IntroductionWelcome| 00:00 | (music playing)
| | 00:04 | Hello! My name is Mark Lefitz, and welcome to
Photorealistic Lighting with Maya and Nuke.
| | 00:09 | In this course, I am going to be
guiding you through the essential tools,
| | 00:13 | techniques, and workflow to effectively
light, render, and composite a CG object;
| | 00:20 | in this case, a futuristic
vehicle to a photographic plate.
| | 00:24 | I will start by discussing image-based
lighting, including HDRI image
| | 00:29 | creation and manipulation.
| | 00:32 | Next, we will jump into Maya to
explore shading, lighting, and rendering.
| | 00:36 | In Nuke, we will look at how to use our
output passes to render our final composite.
| | 00:43 | Finally, we will put some
finishing touches in Photoshop.
| | 00:47 | So let's get lighting with
Photorealistic Lighting with Maya and Nuke.
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| What you should know before watching this course| 00:00 | It is worth mentioning that when
it comes to standard Maya and Nuke
| | 00:04 | operations, I will work with the
assumption that you have a basic working
| | 00:08 | knowledge of these applications.
| | 00:10 | If you are new to 3D, Maya, and
compositing, I would suggest you check out some
| | 00:15 | of the essential training
courses here at Lynda.com.
| | 00:18 | A basic working knowledge of photography
is also helpful. Here are some
| | 00:22 | additional courses you might want to view.
| | 00:24 | All these skills are helpful, but they
are by no means essential for you to
| | 00:28 | follow along and understand this course.
| | 00:30 | I will briefly go over some of the
more important principles as we proceed
| | 00:35 | with the course.
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| Using the exercise files| 00:00 | If you are a premium member of the
Lynda.com Online Training Library, or if you
| | 00:05 | are watching this tutorial on a DVD-ROM,
you have access to the exercise files
| | 00:10 | used throughout this title.
| | 00:13 | As you can see I have an Exercise
folder here on my Desktop; we have another
| | 00:17 | folder called Concept_Car. Within that
we have all our Nuke files that I'll refer
| | 00:23 | to. In our scenes folder, we have all
our Maya scenes that I also refer to
| | 00:29 | throughout the course.
| | 00:30 | We go up one more directory; in our
assets directory, we have our reference
| | 00:36 | files that our Maya files will
reference throughout the course.
| | 00:41 | And if we go into our images
directory, we have our images that have been
| | 00:46 | rendered out from Maya that are used in Nuke.
| | 00:49 | Back in the Concept_Car directory,
we also have our sourceimages.
| | 00:55 | In sourceimages, you will find our
HDRI files, as well as our RAW file used
| | 01:01 | for our back plate.
| | 01:03 | We also have some texture files that
are being used in some Maya shaders.
| | 01:09 | In Maya, it is important to make sure
that you set your project accordingly.
| | 01:14 | You may add your Exercise File directory to
projects, or you can keep it on the Desktop.
| | 01:20 | Wherever you put your Exercise Files,
make sure you set Concept_Car as your
| | 01:25 | project folder, and all your Maya
files will then pull in the proper images,
| | 01:29 | and work accordingly.
| | 01:31 | If you are a monthly subscriber, or
annual subscriber to Lynda.com, you don't
| | 01:36 | have access to the exercise files,
but you can follow along from scratch
| | 01:40 | with your own assets.
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1. Image-Based LightingExplaining image-based lighting| 00:00 | Most commercially sold 3D render
engines that use ray tracing as their primary
| | 00:04 | means to render a scene can accommodate
image-based lighting, or IBL for short.
| | 00:10 | To do this, an artist must use a
spherical image that captures the real world
| | 00:15 | lighting information of
the scene that is being lit.
| | 00:18 | The resulting image is called a high-
dynamic-range image, or HDRI for short.
| | 00:24 | The dynamic range are the values from the
darkest point to the lightest point in the image.
| | 00:30 | This is also called the contrast ratio.
| | 00:34 | To achieve this range, the image is
created with multiple bracketed exposures
| | 00:38 | crunched together in a single 32-bit image.
| | 00:42 | During the post-processing of the
image, it must be made into a 2:1 spherical
| | 00:48 | map, which can then be
projected onto a dome or sphere.
| | 00:52 | Once this image is mapped, it will
allow the ray tracer to extrapolate the
| | 00:56 | information, resulting in
highly detailed, real world lighting.
| | 01:01 | This is not a photography course on
creating HDRIs, but now that we know
| | 01:05 | about image-based lighting, let's see
how we created that HDRI specifically
| | 01:10 | for this course.
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| Examining how the HDRI was created| 00:00 | Let's take a look at how our HDRI was created.
| | 00:03 | For our shoot, we used a standard,
non-full frame Canon 7D DSLR,
| | 00:09 | keeping in mind that full frame
DSLRs are sometimes cost-prohibitive.
| | 00:14 | Because we were using a DSLR with a
smaller sensor, we therefore cannot
| | 00:17 | accommodate the use of a fisheye lens.
| | 00:20 | We can, however, use a
rectilinear wide-angle lens.
| | 00:24 | This just means we have to take more
pictures to cover the gaps that would
| | 00:27 | normally be covered using a wider angle lens.
| | 00:31 | One of the side benefits of using a
normal lens is that more stitching software
| | 00:35 | supports normal lenses.
| | 00:38 | On our 7D, what we used was a
10-20 mm extra wide-angle lens.
| | 00:44 | Since the 7D has a cropped frame, a
crop factor of 1.6 has to be taken
| | 00:50 | into consideration.
| | 00:51 | Therefore, the focal length was set to
around 10 mm, giving us the equivalent of
| | 00:57 | a 15 mm lens on a full frame camera.
| | 01:01 | Also, since our 7D can only auto-bracket
three total stops, we manually
| | 01:07 | bracketed seven full stops;
| | 01:09 | three stops up, three stops
down, and one stop in the middle.
| | 01:14 | Mounting the camera on a tripod, we
shot a full circle taking care to create a
| | 01:19 | bit of overlap from one view to the next.
| | 01:22 | For each camera position, we bracketed
our exposures three up, and three down,
| | 01:27 | with one in the middle, for
a total of seven exposures.
| | 01:31 | The bracketed exposures were then
stitched using PTGui Pro, giving us a file
| | 01:37 | size that is roughly 17,000
pixels wide, and 4000 pixels tall.
| | 01:43 | Notice the gaps at the
top and bottom of the image.
| | 01:46 | This is because we did not cover
the nadir directly below, or the
| | 01:50 | zenith, directly above.
| | 01:52 | So we had to extend both the sky and
ground to end up with a roughly 17,000
| | 01:58 | pixel wide, and 9000 pixel tall image.
| | 02:01 | A lot of paint work to end up with the
correct 2:1 aspect ratio suitable for
| | 02:06 | spherical mapping in mental ray.
| | 02:09 | This file size is too large to
work with, so I saved out a half- and
| | 02:13 | quarter-sized versions.
| | 02:15 | I simply imported the final large image
into Nuke, placed a Reformat node after
| | 02:21 | the image, and set the Reformat Type to Scale.
| | 02:26 | Then I set the scale to either
0.5, or 0.25, and wrote that file out.
| | 02:33 | I could do the same thing
using Photoshop as well.
| | 02:36 | So now that we know how our HDRI was
created, let's examine the best way to
| | 02:40 | capture our background plate.
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| Shooting the background plate| 00:00 | On some projects, the plate
photography or video is provided to us via the
| | 00:05 | client, and we have to
match whatever is given to us.
| | 00:08 | Other times we are in the position
of creating or choosing these assets.
| | 00:13 | If you are fortunate enough to be in
this position, then I would recommend that
| | 00:16 | the background plate photography be
taken at the same time as the HDR image to
| | 00:21 | ensure the same lighting conditions.
| | 00:24 | When shooting props or vehicles, it is
a good idea to analyze those objects
| | 00:28 | before going to the location.
| | 00:31 | Make note of the body lines, the
proportions, the paint color, and the overall
| | 00:35 | styling. This will help you in
choosing your lens, and lens height.
| | 00:40 | Low, aggressive sports cars almost require
a wider lens, and a lower mounting point.
| | 00:46 | With sedans, you can lift the camera maybe
a bit higher, and choose a narrower lens.
| | 00:51 | In either case, it is a good idea to
shoot the vehicle with several lenses, and
| | 00:56 | create a contact sheet of your results.
| | 01:00 | Shoot front, back, and side to get full
coverage. See what looks good, then match
| | 01:05 | the angle of view and lens
height when shooting the plate.
| | 01:09 | Sometimes, as in the case of this course,
we don't have an actual object to shoot,
| | 01:14 | but we can do the same exercise within
Maya by simply changing the focal length,
| | 01:19 | and rendering several
angles, using the default light.
| | 01:23 | If I open up the Render Settings window,
and we scroll down to the bottom under
| | 01:28 | the Common tab, we're going to notice
there is pulldown under Render Options.
| | 01:33 | Let's make sure Enable Default
Lighting is selected for making this contact
| | 01:37 | sheet, but turn this off
for the rest of the course.
| | 01:41 | You can also see that I've chosen to
Render Using mental ray that I'll be using
| | 01:45 | throughout the rest of this course.
| | 01:47 | Next, let's select our camera, and
I'm going to open up the Attribute by
| | 01:52 | selecting Control+A. Now what I can do is
I can go to my Perspective view, under
| | 01:58 | View > Camera Attribute Editor.
| | 02:01 | That will give us the
parameters to change the focal length.
| | 02:05 | In this particular case, my
Focal Length is set to 50.
| | 02:09 | Let's give it a render.
| | 02:12 | So here we have our car, with a focal
length of 50, and our default lighting.
| | 02:17 | So I went ahead and I change the camera
Focal Length to various numbers, and I
| | 02:21 | rendered out several different renders.
| | 02:24 | So let's take a look at that, and
see what that looks like in Nuke.
| | 02:27 | So, within Nuke,
I brought in all my renders.
| | 02:31 | In this particular case, I rendered the
camera from a High position, a Medium
| | 02:36 | position, and a Low position from the
height of the ground. And then from each
| | 02:41 | of those positions, I rendered out three
focal lengths; a 30 mm, a 40 mm, and a 50 mm,
| | 02:48 | do you can see the differences, and how the
car looks within each of those focal lengths.
| | 02:55 | Once the renders were complete, I brought
all the renders into a contact sheet node.
| | 03:02 | This mimics the contact sheet we were
looking at before, so now I can view all
| | 03:07 | the vehicles, and all the
different focal lengths in a single image.
| | 03:12 | I happened to like the lower, more
aggressive look for the concept car.
| | 03:15 | Also, the lower length lens seems to
make the front end of the vehicle too
| | 03:20 | bulbous, which is the
Low 30 mm lens, as we can see here.
| | 03:29 | So, based on this analysis, we shot
our background plate using a 50 mm lens
| | 03:34 | mounted on a tripod about
3 feet off the ground.
| | 03:37 | Now that we know how our background
plate was shot, let's take a more in-depth
| | 03:41 | look at what we have to work with.
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| Analyzing and color correcting the background plate| 00:00 | Once the background plate has been
shot, we need to carefully study it to
| | 00:04 | determine how to light our object.
What is the sun and shadow direction? What
| | 00:09 | are the darkest darks,
and the brightest brights?
| | 00:12 | Let's open the following image, which can
be found in the sourceimages directory.
| | 00:17 | Notice in the image, we chose that the
shadows are not fully black, and that the
| | 00:21 | color of the sun is warm,
not midday white.
| | 00:25 | We need to take this into consideration
when setting up our lighting.
| | 00:29 | A good photographer will get the right
lighting, framing, and lensing, but there
| | 00:33 | will typically need to be
further enhancements on the image.
| | 00:37 | The great thing about shooting RAW is
that with the 32-bit file format, there is
| | 00:42 | plenty of pixel information to manipulate.
| | 00:45 | There are several ways we can color
correct an image. We can do it now in
| | 00:49 | Photoshop, or we can do it
in our composite.
| | 00:52 | Here is a quick way to color
correct the RAW image in Photoshop.
| | 00:57 | Let's close our preview. We notice in
our sourceimages directory our Camera RAW
| | 01:03 | file. Let's just Click+Drag,
and drop into Photoshop.
| | 01:08 | This will automatically
initialize Camera RAW.
| | 01:11 | Now that we're in Camera RAW, let's
first tint the image, so it's a little
| | 01:15 | bit warmer overall.
| | 01:17 | And now let's bring down the Exposure,
which basically darkens the image, and we
| | 01:23 | can lift our blacks, which
basically gets our shadows darker.
| | 01:28 | Let's do an overall Brightness
increase, and increase our Contrast.
| | 01:33 | Once we have color corrected it, let's
save it in the sourceimages directory as
| | 01:37 | a JPEG image. Click Save; I will
denote a .cc, which means color corrected.
| | 01:45 | We have to save it as something other
than a RAW file, like a .JPEG, or .TIFF for
| | 01:51 | Maya to read it as an image plane.
| | 01:54 | Save the file. Now we're going
to close our Camera RAW; say Done.
| | 01:59 | Another great way to color
correct the image is in Nuke.
| | 02:02 | Since Nuke does not read Camera
RAW files, like CR2s from Canon;
| | 02:07 | we have to convert it
to another file format.
| | 02:11 | Here we are in Nuke.
| | 02:12 | Now let's bring our saved TIFF image,
that is, non-color corrected, into the file.
| | 02:18 | Here we can Click+Drag, and bring
it directly into the application.
| | 02:23 | I hit 1, which is going to select Viewer1
onto our TIFF image, so now we can view it.
| | 02:30 | We can now add a color correct. We
can do this in a couple different ways.
| | 02:35 | We can either hit the Tab button, which
brings up all our Nuke nodes, and we type
| | 02:40 | in color correct, and within a
list we select ColorCorrect.
| | 02:43 | Let's delete that, and I'll
show you another way to do it.
| | 02:46 | Select the Read node, and this time
let's just hit the letter C, and that will
| | 02:51 | also create the ColorCorrect node.
| | 02:54 | Now that our color correct is ready
to use, let's go ahead and bring up our
| | 02:58 | contrast, dial down our gamma,
and let's increase the gain.
| | 03:05 | These are very similar operations
that we did in Photoshop to get the same
| | 03:09 | type of look as before.
| | 03:11 | It seems as though the ground is a little
bit bright, so we need to adjust that as well.
| | 03:16 | Let's create a Rotoscope node, so we
can just change the ground portion.
| | 03:21 | So Tab, and we type in Roto, set
the Rotoscope apart to the side here.
| | 03:28 | Then we're going to double-click
to bring up our parameters.
| | 03:31 | Now, by selecting the Control and Alt key,
we can lay down some beginning points of
| | 03:37 | the Rotoscope just to outline the road.
| | 03:40 | The final click will enclose the
Rotoscope, and we can even hit the spacebar to
| | 03:46 | enlarge the entire image onto the screen.
| | 03:48 | So now let's go ahead and fine-tune
those points, highlighting just the road.
| | 03:56 | Spacebar again, so we can
get back to our Node window.
| | 04:01 | What I like to do is I like to have
the in leader, which is this leader right
| | 04:05 | here, come from the image file,
so it knows the size of the image.
| | 04:10 | Now what we can do is
add another color correct.
| | 04:14 | Hit the letter C, we bring our
mask leader into the Rotoscope.
| | 04:20 | Now what we can do is double-click this
second ColorCorrect, so we have our parameters.
| | 04:26 | Back to the Rotoscope node, we invert it.
| | 04:29 | So now only the inside of the Rotoscope is
going to be affected by this color correct.
| | 04:36 | So with the ColorCorrect selected, we
can bring down the gamma, and also the
| | 04:41 | gain to darken the road.
| | 04:43 | Finally, what we want to do is we want
to write this image out, so we can use
| | 04:48 | that now in Maya as an image
plane, and also in our final comp.
| | 04:54 | So let's move this viewer to the
side, Tab, and we can type in write.
| | 04:59 | The other thing we can do is we
select the ColorCorrect node, and hit the
| | 05:03 | shortcut key for W; that
will create a Write node.
| | 05:07 | Let's go into our Explorer browser window,
let's Copy+Paste; Control+C, and now we go
| | 05:15 | into our file, and we Control+V,
telling where we want to write our image.
| | 05:20 | Let's add one more Backslash, and type
in the name of the file that we want to save.
| | 05:27 | So in this case, we're going to type in
IMG_2117_colorcorrect, and we can say .jpg.
| | 05:38 | We have to make sure that the JPEG
quality is set to 1, and now we can render
| | 05:43 | that out by simply hitting
the Render button, and saying OK.
| | 05:47 | I am going to Cancel that out. I
already have a version of that saved.
| | 05:52 | I have shown a couple of different ways
to color correct the background plate.
| | 05:55 | Now let's take a look at how we
can color correct the HDRI as well.
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| Correcting the HDRI| 00:00 | Just as we color corrected our background
plate, we can do the same to the HDRI image.
| | 00:05 | Let's read in our panoramic
HDRI quarter-sized image into Nuke.
| | 00:10 | The first thing we are going to
do is add a ColorCorrect node.
| | 00:13 | Let me hit the spacebar; zoom out here.
| | 00:16 | We are going to open up our Windows
Explorer window, and here is our
| | 00:23 | quarter-sized panoramic image that we
created in a previous lesson.
| | 00:27 | So minimize that,
and let's view the HDRI image.
| | 00:33 | And again, we're going to
create a color correct node.
| | 00:35 | We can either tab ColorCorrect, or
press the letter C for the hot key.
| | 00:42 | Let's first bring up our contrast just a
tad, and we are going to bring down our
| | 00:48 | gamma, and let's bring up our gain.
| | 00:50 | And the point of this is, we are going
to look now at our ColorCorrect for our
| | 00:54 | background image;
put that on the number 2,
| | 00:57 | so now we can toggle between number 2, and
number 1, number 1 being our HDRI image.
| | 01:03 | We are trying to get
them roughly in the same world,
| | 01:06 | so when I bring this HDRI image
into Maya, the lighting will match.
| | 01:11 | The HDRI was taken in a slightly different
location and time of day than the back plate,
| | 01:15 | so we have to accommodate for these changes.
| | 01:18 | The HDRI was taken on dirt, but the
back plate shows very little very dirt.
| | 01:22 | We need to adjust the color of the
dirt to more closely match the background
| | 01:26 | plate, to get the proper bounce lighting,
and mimic that color reflected onto
| | 01:30 | the vehicle from below.
| | 01:32 | Let's create a constant at the
same resolution as the scaled down HDRI.
| | 01:38 | Tab button, Constant, and now
let's double-click the Constant, so the
| | 01:44 | parameters are now shown.
| | 01:46 | Let's select the ColorCorrect.
Hit number 2,
| | 01:49 | so we bring that into the viewer.
| | 01:52 | Now, within the Constant,
we select our color picker.
| | 01:56 | Holding down the Ctrl and Shift key, we
can now select the color of the ground.
| | 02:03 | Back to the Constant, make sure that
the Constant size is going to be the
| | 02:07 | same as the HDRI image.
| | 02:10 | Select the ColorCorrect, number 1,
and now under Format, we select the
| | 02:16 | 4383 by 2185 resolution.
| | 02:20 | So now they are both going
to be the same resolutions.
| | 02:24 | Next, I'm going to add a Bezier.
| | 02:27 | Click in the workspace, select X,
and we are going to make sure the TCL
| | 02:33 | option is selected.
| | 02:35 | We are going to type in Bezier, with a
capital B. Hook that up to the Constant.
| | 02:41 | Holding down Ctrl+Alt key, we are going
to place a Bezier carefully around just
| | 02:47 | the dirt area to isolate that area.
| | 02:50 | So, we are going to set
some points on the Bezier,
| | 02:54 | and now what we can do, just one click
in our viewer window, hit the spacebar,
| | 03:00 | and now we can bring that full size up.
| | 03:03 | This gives me the opportunity now to go
in and finely tune the Bezier curves.
| | 03:10 | I'm only isolating just the ground.
| | 03:16 | Open this one up a little bit.
There we go!
| | 03:19 | That looks good for now.
Spacebar to resize it back.
| | 03:24 | Lastly, what we want to do; we want to
bring this Constant color on to the ground.
| | 03:29 | To do that,
we have to create a Merge node.
| | 03:32 | So we can either hit the Tab bar, and
type in Merge, or we can use Nuke's
| | 03:39 | hot key, which is M. Make sure that our
Merge node, the operation is selected to screen.
| | 03:47 | Now set the A leader to the Bezier;
the B leader to the ColorCorrect.
| | 03:54 | One last thing we need to do; as you
notice, the color is outside of the
| | 04:00 | Bezier. We have to now go to
our color, and set it to black.
| | 04:07 | Back to the Bezier tab, we
are going to invert that color.
| | 04:11 | Finally, back to the Screen node by
double-clicking, we now can mix in the
| | 04:16 | amount of color that we like.
| | 04:18 | Now, with our ColorCorrect selected,
we can hit the number 2, and we can dial
| | 04:24 | between the two, and see
if that is what we like.
| | 04:28 | So, let's go back to the screen, I think it
might be a little bit heavy. Bring that down.
| | 04:33 | Now we can compare our original
HDRI with our color corrected HDRI.
| | 04:39 | Our last order of operation here
is we have to write out the file.
| | 04:44 | So we are going to hit the Tab button,
type in write, or the Nuke shortcut is
| | 04:49 | simply W. Let's go ahead and
bring our Explorer window up.
| | 04:53 | Let's Copy+Paste where we want it to
write to; in this case, our sourceimages
| | 04:57 | directory, and in the file,
we are going to paste.
| | 05:01 | And add a backslash, and type in the
name of the file that we want to save.
| | 05:08 | Once that file name is in, we simply hit
Render, and it will render it into our
| | 05:13 | sourceimages directory.
| | 05:15 | Now that we have our HDRI and our back
plate color corrected, and sized properly,
| | 05:20 | let us use them in Maya.
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2. Asset IntegrationUsing Maya references to import the geometry| 00:00 | We need to do some organizational work
before we can begin to light our vehicle.
| | 00:05 | The general idea is that we will store
a progressively changing unshaded model
| | 00:10 | in our assets directory.
| | 00:12 | In another Maya file, this
unshaded file will be referenced in using
| | 00:17 | Maya's Reference Editor.
| | 00:20 | This is where we add shading and lighting.
| | 00:23 | We will call this our shading file, and
progressively save changes to the scenes directory.
| | 00:29 | In a fresh version of Maya with
nothing in it, we are going to
| | 00:32 | File > Reference Editor.
| | 00:36 | In Reference Editor, we are
going to go File > Create Reference.
| | 00:41 | Now what we do is we have to
browse to our assets directory.
| | 00:45 | In our assets directory, this is where
our unshaded geometry only model lives.
| | 00:52 | So let's go ahead, and we are going to
select version 3 of our reference file.
| | 00:59 | Go ahead and minimize our Reference
Editor, and we are going to select 5 to turn
| | 01:04 | on hardware shading.
| | 01:06 | So now, if we open up our Outliner by
going to Window > Outliner, and let's open
| | 01:13 | up our hierarchy,
we can see our grouped car.
| | 01:18 | What I've done is I've gone ahead and
I've grouped it in terms of windows,
| | 01:23 | we have an interior layer;
| | 01:25 | turn off the shading, so we can see
inside the car. Hardware shading back on.
| | 01:30 | This is our sheet metal.
| | 01:32 | I separated out the front wheels;
| | 01:34 | We have a front wheel left, and we have
a front wheel right, and we have a rear
| | 01:42 | wheel right, and we have a rear wheel left.
| | 01:47 | I primarily do this so I can go
ahead and select the two front wheels,
| | 01:53 | and now I can rotate them, to give
the car maybe a more aggressive look.
| | 01:59 | I also have all the axles, and the light
assemblies, and finally, the side mirrors.
| | 02:09 | The reason we do this is that any time
our geometry changes -- pieces added,
| | 02:13 | deleted, separated, or UVed -- we
don't have to go through the process of
| | 02:18 | re-shading our geometry.
| | 02:20 | We simply update the model, version up to a
higher number, then version up our reference.
| | 02:26 | So let's go ahead and open
up that Reference Editor again.
| | 02:30 | This is a good setup when multiple
artists are working on the same project in
| | 02:33 | different capacities.
| | 02:35 | One artist can be modeling, while
other artists are shading and lighting.
| | 02:39 | When the model is progressed, the
shading file is simply versioned up to the
| | 02:43 | latest geometry file.
| | 02:46 | Let's go ahead and
open up our Shading file.
| | 02:49 | Tab over to another Maya file.
| | 02:52 | This is our shading file.
| | 02:54 | Open up our Reference Editor.
| | 02:55 | You will notice it's
bringing in a fresh reference.
| | 02:59 | In here, we are going to
open up our Hypershade window,
| | 03:02 | so we go to Window >
Rendering Editors > Hypershade.
| | 03:07 | Inside, you will notice several mia
material shaders, specifically designed for
| | 03:13 | the mental ray render engine.
| | 03:15 | We can put the vehicle off to the side,
and now we can start selecting various
| | 03:21 | pieces of our geometry.
| | 03:23 | Let's go ahead and open up our Outliner
window, open up our hierarchy, and now
| | 03:31 | we can select, for instance,
all the sheet metal.
| | 03:35 | We find our paint shader, we
right-click, and Assign To Selection.
| | 03:40 | Now all our paint material
is assigned simultaneously.
| | 03:44 | We can do the same thing now
for our windows.
| | 03:48 | Let's select our windows group.
| | 03:49 | Let's find our Window shader,
right-click, Assign Material To Selection.
| | 03:58 | We can continue on
assigning materials to the car.
| | 04:01 | So, for instance, maybe what we do is
we assign the insides of our wheel to
| | 04:07 | a nice Chrome shader.
| | 04:08 | Let's find the Chrome shader.
| | 04:11 | They're actually listed alphabetically.
| | 04:13 | Right-click, and Assign To Selection.
| | 04:17 | We can also select individual
pieces outside of the hierarchy.
| | 04:22 | So for instance, this piece right here
on the front, maybe I don't want that as
| | 04:25 | red paint; I actually want it as silver paint.
| | 04:28 | So we are going to right-click, and Assign
To Selection for our SilverPaint shader.
| | 04:34 | So no matter what kind of geometry
you are shading and lighting, it is
| | 04:38 | important to use references
with a well organized hierarchy.
| | Collapse this transcript |
| Creating a 3D camera to match the plate| 00:00 | To match the Maya camera to the camera
that shot the plate, we need to get the
| | 00:05 | metadata from our RAW image.
| | 00:07 | This data will tell us our file
size and lensing information that we
| | 00:11 | can replicate in Maya.
| | 00:12 | Open Photoshop, and click+drag
our RAW file into the application.
| | 00:18 | We get our Explorer window, we click+drag
in our CR2, which is our RAW image, and
| | 00:24 | that will bring up Camera RAW.
| | 00:26 | Now, we are not going to do any color
correcting here; we are simply going to
| | 00:30 | use this to get the information
from the lens.
| | 00:32 | We notice it was taken with an ISO of a
100, the lens was shot with 24-105, and
| | 00:39 | it was shot at 50 millimeters.
| | 00:41 | So, what we want to do is, in Maya, we want
to create a 50 mm lens based on this data.
| | 00:48 | We are done with that, and let's open up
Maya back to our shading file where we left off.
| | 00:54 | First thing we want to do is we want
to create a single node Maya camera, and
| | 00:59 | name it something like shotCam.
| | 01:01 | So, let's go up to the Create menu,
Cameras, and we are going to create a
| | 01:05 | single node camera.
| | 01:07 | In the channel box, we're going to select
that, and we are going to call this shotCam.
| | 01:12 | Now let's go ahead, and under panels,
we're going to go to Perspective, and we
| | 01:16 | see our shot camera.
| | 01:17 | Let's go ahead and look through that.
| | 01:19 | Let's open up our
Attribute Editor for that camera.
| | 01:23 | Back in Camera RAW,
Focal Length was set to 50.
| | 01:26 | Here in Maya, the default is 35,
| | 01:28 | so let's go ahead, and set that to
50 to match our live-action camera.
| | 01:34 | We need to open up the
Render Settings window.
| | 01:38 | If we scroll down to our Image Size,
we have to set an initial Image Size.
| | 01:43 | Let's try HD 720 for now,
under Common > Image Size > Presets.
| | 01:50 | Let's open up the Presets,
scroll down, HD 720,
| | 01:55 | and we can lock that.
| | 01:56 | So any time we change this number,
the aspect ratio will be locked.
| | 02:01 | We can always make this smaller at render
time if we want to, because it is still
| | 02:06 | a fairly large image to render.
| | 02:09 | Let's scroll back up here under Renderable
Cameras, and make sure our shotCam is selected.
| | 02:15 | That way, when we render in Batch mode,
we have to change our menu selection to
| | 02:20 | Rendering, Render > Batch Render.
| | 02:22 | The shot camera will be the
proper camera that is being rendered.
| | 02:27 | Let's go ahead, and under View > Camera
Settings, let's turn on our Resolution Gate.
| | 02:34 | Now we know we locked in our 1280 by 720
to our shot camera. We can dolly, tumble,
| | 02:42 | and track, and position our car.
| | 02:45 | Our next step is we need to create
a polygon plane with at least three
| | 02:49 | subdivisions, and we will try and
match that up to the ground plane of
| | 02:53 | the background image.
| | 02:55 | We go to Create > Polygon Primitives > Plane.
| | 03:00 | I like to turn Interactive Creation off;
| | 03:04 | Create > Polygon Primitives >
Plane. Hit R for scale.
| | 03:09 | Let's scale that up in the Channels box.
| | 03:12 | Let's select Polygon Plane 1.
| | 03:14 | Reduce the subdivisions,
let's say, to around 5.
| | 03:18 | We can always increase those
subdivisions, or reduce them.
| | 03:22 | Let's go under
View > Camera Attribute Editor.
| | 03:24 | We are going to scroll down
under Environment.
| | 03:29 | We see the Image Plane >
Create button. Let's select that.
| | 03:34 | Now, we need to browse for our image plane.
| | 03:37 | We select the Browse button, and in this
particular case, we are going to select
| | 03:41 | our TIFF that we
color corrected in Nuke.
| | 03:45 | Hide the Attribute Editor.
Select 4 to turn hardware shading off.
| | 03:50 | We're now working in a 50 mm lens.
| | 03:54 | Dolly, tumble, track, and move, and
rotate the camera into position in such a
| | 03:59 | manner so the polygon plane will
match the perspective of the road.
| | 04:03 | Let's scale up our ground plane, maybe
make it a little bit longer, and we use
| | 04:09 | the lines of the ground plane
to match the lines of the road.
| | 04:13 | Let's center the car as well.
| | 04:16 | Once we are satisfied with our camera
positioning, we need to lock our camera.
| | 04:21 | So let's go back up to View, select
Camera, and in the Channels box, we need to
| | 04:25 | select the Translates, the
Rotates, the Scale, and the Visibility.
| | 04:29 | We simply select the top one, the first
Translate X, select the last Visibility,
| | 04:34 | Shift+Select, right-click,
and we lock selected.
| | 04:39 | Now our camera is locked into position.
| | 04:41 | So, this is one method to
match still plate photography.
| | 04:45 | If you're using running footage, you
might want to check out Matchmoving
| | 04:49 | Software, such as Boujou, SynthEyes,
3D Equalizer, Matchmover, and PFTrack.
| | 04:56 | Now that we have our Maya camera, we
need to set up our image-based lighting.
| | Collapse this transcript |
| Setting up image-based lighting| 00:00 | Now, we can use our HDRI image
to begin lighting the geometry.
| | 00:04 | The workflow I suggest you use is to
dial in your image-based lighting first,
| | 00:09 | then add your physical lights to the scene.
| | 00:12 | Tweak the intensity of the IBL until it
feels comfortable using final gathering
| | 00:17 | to get the desired look and feel.
| | 00:19 | Let's go ahead and hide the ground plane;
select it, Ctrl+H, and let's open up
| | 00:25 | our Render Settings window.
| | 00:28 | Next, let's go to the Indirect Lighting tab.
| | 00:31 | Next to Image Based Lighting, select Create.
| | 00:34 | Next to the Image Name, let's browse for
our quarter-sized color corrected HDRI image.
| | 00:41 | Select it, and Open.
| | 00:44 | It's important to make sure that
the Mapping is set to Spherical.
| | 00:47 | Also, if we scroll down, notice that
there is a Primary Visibility toggle.
| | 00:53 | This is very important, because when we
do our final render, we want to make sure
| | 00:58 | Primary Visibility is set to off.
| | 01:01 | That way, when we render, we
don't see the IBL in the background.
| | 01:05 | But for our purposes right
now, let's select it to on,
| | 01:09 | so when we are in our viewport, we can
actually position the IBL, and view it.
| | 01:14 | Let's go back to the Render Settings window,
and turn on Raytracing, and Final Gathering.
| | 01:20 | So, under Features, Raytracing; on.
Back to Indirect Lighting, and let's
| | 01:25 | turn Final Gathering on.
| | 01:28 | Let's just leave these at
default settings for now.
| | 01:31 | And now is a great time
to do some test renders.
| | 01:34 | Let's minimize our Render Settings window.
| | 01:37 | Render the current frame using mental ray.
| | 01:42 | So, as you can see, we are starting to
get a little bit of lighting in here,
| | 01:46 | but what we are going need to do is we
are going to increase the value of the IBL.
| | 01:52 | Let's go back to the Render Settings
window, Indirect Lighting tab; let's go to
| | 01:57 | the Image Based Lighting file.
| | 02:00 | Under Color Gain, let's select the color
swatch, and increase the value to 4, and
| | 02:07 | go ahead and save this render in our
render buffer, and let's do another render.
| | 02:14 | We can always go back to the Color
Gain in the Render Settings window, and
| | 02:18 | dial it in to taste.
| | 02:20 | If we close our Render view for a
moment, let's go to our Perspective view;
| | 02:25 | spacebar, and then right-click;
Perspective View.
| | 02:29 | Now, let's turn our lighting
hardware to 6.
| | 02:33 | That way we can view our
IBL in our Perspective view.
| | 02:38 | In the OpenGL view, we see a seam
where the ends of the image meet.
| | 02:43 | This is not the most desired effect,
| | 02:45 | but because we used normal lens, and
had paint in the gaps, the HDRI is not
| | 02:51 | perfectly spherical.
| | 02:52 | But we can position it in such a way where
we will not see that seam in our final render.
| | 02:59 | Also notice that our sun is coming from
the opposite side of the car from where
| | 03:03 | it needs to be, based on our back plate.
| | 03:06 | This is because the HDRI image was
taken at a much later time of the day than
| | 03:13 | the early morning of the back plate,
| | 03:15 | nut this can be corrected in Nuke.
| | 03:18 | So, let's go ahead and open up Nuke.
| | 03:21 | We have our color corrected HDRI file.
| | 03:25 | We view our color correction node.
| | 03:26 | What we can do is we can add a
reformat to flop the sun to the
| | 03:32 | opposite direction.
| | 03:34 | So, let's go ahead and hit Tab, type
in Reformat to bring the Reformat node
| | 03:39 | below the ColorCorrect.
| | 03:41 | Now, under type, we set it to scale.
| | 03:45 | We make sure the scale is 1.
| | 03:47 | So there's no change in scale
from the original image file.
| | 03:51 | Now we simply select the Flop node, which
takes the sun, and the entire image, and
| | 03:57 | flops it around, keeping the same scale.
| | 04:00 | In the Write node, let's go ahead and
add the word flopped, with an underscore,
| | 04:08 | and let's go ahead and render
that out, which I already have done.
| | 04:12 | So, let's go back to Maya.
| | 04:14 | Back into our Render globals; our
Render Settings window. Let's go to our Image
| | 04:19 | Based Lighting, and now we browse for
the flopped version, color corrected.
| | 04:28 | Now when we view the HDRI in the
OpenGL, we notice that the sun is coming
| | 04:34 | from the opposite side of the car,
much more in line from where the sun is
| | 04:38 | coming in the back plate.
| | 04:40 | Let's go back to our shot camera,
and let's do another render.
| | 04:46 | Let's put this one in
the buffer, and hit Render.
| | 04:50 | Now, we can look at the
different types of images that we get.
| | 04:53 | We notice here that the sun is coming
from the left side. In our new render, the
| | 04:57 | sun is coming from the proper
direction of where the back plate was shot.
| | 05:02 | Feel free to play around with the
rotation and the intensity of the IBL to
| | 05:06 | create different looks.
| | 05:07 | Once you have something you like, we
need to determine how large to render
| | 05:11 | our file.
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| Determining render resolution| 00:00 | The render size I've been
using is primarily used for video.
| | 00:04 | What if I wanted to render for print?
| | 00:06 | Let's look a little more in
depth our render resolution.
| | 00:09 | In order for us to figure this out,
let's open the background image in Nuke,
| | 00:14 | using our background color
correction file. Open up Nuke.
| | 00:18 | Here we are in our color
corrected background file.
| | 00:21 | We are going to select our last node in
the chain, which is our ColorCorrect. Tab.
| | 00:26 | Let's type in Crop, and add the
Crop node below our ColorCorrect.
| | 00:30 | Let's manually bring in the edges of our crop.
| | 00:34 | What I like to do is I like to try
and leave about the same amount of black
| | 00:37 | space on both sides.
| | 00:39 | So, what we're doing is we're going
from a landscape image, which is more
| | 00:43 | horizontal, to an image that has
more height than it has width;
| | 00:48 | something that is going to be
much more workable for print.
| | 00:51 | What we need to do next is we need to jot
these numbers down; the width, and the height.
| | 00:56 | So we have 4620 by 3456.
| | 01:01 | Now, once we have those numbers down,
we go back to Maya, open up our Render
| | 01:06 | Settings window, turn off
Maintain width/height ratio.
| | 01:10 | That way, the width and
the height are not locked.
| | 01:14 | Let's type in our numbers
that we wrote down; 4620
| | 01:18 | -- and let's minimize our Render window --
by 3456.
| | 01:25 | Let's minimize our Render Settings window.
| | 01:27 | Now, our Render view in Maya
matches our Crop window in Nuke.
| | 01:33 | What are we going to render for this course?
| | 01:35 | Well, since we want to render more
for video, we are going to go back to
| | 01:40 | Maintain width/height ratio, we're
going to use our Preset, and we are going
| | 01:44 | to set it to HD 720.
| | 01:47 | You might want to experiment rendering
a little bit higher. The same aspect
| | 01:50 | ratio of 177 is also HD 1080, which
is what is normally called a 2K image.
| | 01:58 | Now that we have our render resolution,
we need to add lights to our scene,
| | 02:02 | which we will do in the following chapter.
| | Collapse this transcript |
|
|
3. LightingExploring mental ray light types| 00:00 | Since we are getting a majority of our
reflections and some lighting from our
| | 00:04 | HDRI, we still need to add more
lights to our scene to enhance the shape of
| | 00:08 | the vehicle, and also to accentuate
areas of the object that might not be
| | 00:12 | getting enough light.
| | 00:14 | Adding lights also creates more
separation of the object from the background.
| | 00:19 | If we go under the Create menu, under
Lights, we can see a variety of different
| | 00:24 | lights that are accessible to us.
| | 00:27 | Typically, I never use ambient
lights; I only use directional lights,
| | 00:31 | spotlights, or area lights.
| | 00:34 | So, let's go ahead and take a look
at our first selection, which is the
| | 00:37 | Directional Light, and hit the W key.
| | 00:41 | Let's go into Panels > Perspective, and
let's just move that directional light out
| | 00:47 | of the way, hit the E key to
rotate the light, and back to W.
| | 00:52 | What we can do is we position the light
such as we are mimicking the direction
| | 00:59 | of the sun, based on the
back plate that we have.
| | 01:02 | If we open up our Outliner, if we go
under Window > Outliner, I went ahead and I
| | 01:07 | created three different lights here.
| | 01:09 | So, let's go ahead and delete the
Directional Light, and we are just going to
| | 01:12 | use the one I already have in here.
| | 01:14 | And we are going to go to
Display, and Show Selection.
| | 01:17 | So, we can see the Directional Light up here.
| | 01:21 | One more thing, if we go to Ctrl+A, look
at the lights' attributes; we scroll down here.
| | 01:27 | For each of these lights, I turned on Line
Ray Trace Shadows, so we can see what kind of
| | 01:30 | shadow quality we get.
| | 01:32 | Close that out, back to Perspective view,
shot camera, and render out our first light type.
| | 01:39 | I just put a Lambert shader on the
ground, so we can kind of see the effects of
| | 01:45 | the shadow, and let's go ahead and
save this render in our render buffer.
| | 01:51 | Directional lights are really good at
simulating the sun, but their shadows are
| | 01:55 | generally too crisp; they
have very sharp edge to it.
| | 01:59 | Also, their specular highlights, bright
shiny parts that reflect in the shader
| | 02:04 | material is generally too focused and round.
| | 02:08 | The other thing about directional
lights that I typically don't like: the light
| | 02:12 | quality is very even, and I
generally like to have pockets of light.
| | 02:18 | That way, I can accentuate
different parts of the car.
| | 02:21 | Let's take a look at another light
type that we have, which is a spotlight.
| | 02:25 | So let's go back to our Window > Outliner.
| | 02:29 | Let's go ahead and hide the
directionalLight, minimize the Render window,
| | 02:32 | and I am going to go into Perspective View,
just so you can kind of see what I'm doing here.
| | 02:37 | You can see light type right up over here.
| | 02:40 | I'm going to hit the Ctrl+H button; hide it.
| | 02:42 | Let's select the spotlight, Display > Show >
Show Selection, and now here's our spotlight.
| | 02:49 | Another little trick I like to do is I
like go into Panels > Look Through Selected.
| | 02:54 | So let's go ahead and do that.
| | 02:56 | We can just basically look through the
selected light, and that way it's a much
| | 03:00 | easier way to position the light; make
sure that the vehicle or whatever object
| | 03:04 | we're lighting to is
fully framed into our light.
| | 03:08 | So back to Panels, let's go back to our
shot camera, and let's do another render.
| | 03:14 | We have this one in our buffer.
| | 03:16 | So now we're just going to hit the Render
button; redo previous render in mental ray.
| | 03:22 | So now let's save that
one in our buffer as well.
| | 03:24 | And let's go ahead and open up the
Attribute Editor for our selected light
| | 03:28 | type: our spotlight.
| | 03:30 | Ctrl+A. Spotlights are great, because
they give us a lot of different attributes
| | 03:35 | that we don't normally have in other
light types, such as our Cone Angle, how
| | 03:40 | big the cone is, and the Penumbra, which is
the falloff, the softness of the cone,
| | 03:45 | and also the Dropoff.
| | 03:48 | But as you can tell, spots are particularly
good for interior scenes, because
| | 03:54 | they create soft shadow effects,
| | 03:56 | but they're also difficult to match
to exterior scenes like we have here,
| | 04:00 | because they really don't mimic the
effects of the sun, which leaves us to our
| | 04:05 | final light type, and that is our Area Light.
| | 04:09 | So, let's minimize our Render view, and
let's close out our Attribute Editor for now.
| | 04:15 | Let's go back to our Perspective.
| | 04:17 | We are going to hit Ctrl+H, hide our
spotLight, and I created an areaLight in
| | 04:24 | here, and let's go to Show > Show Selection.
| | 04:27 | Now, we'll go finally back to our shot
camera, and let's go ahead and take a
| | 04:35 | look real quickly at some of the
parameters into our areaLight.
| | 04:40 | And just to let you know, I turned
on ray trace shadows. Let's scroll up.
| | 04:44 | I cranked up that the Intensity to
about 10, and I am able to adjust the Color.
| | 04:49 | In this particular case, I just made it
warm to kind of match the rocks behind it.
| | 04:54 | Let's go ahead and open up our Render
view, and I know we've put that one in our
| | 04:59 | render buffer, but let's do it again anyway,
| | 05:01 | and let's go ahead and
re-render our shot camera.
| | 05:07 | Here's our render with our area light.
| | 05:10 | So you notice that we are getting a nice pool
of light closer to where the light source is,
| | 05:16 | so the light tends to fall off, and
we get those big, broad, more specular
| | 05:20 | highlights closer to the light, which
is going to basically require us to add
| | 05:24 | more area lights, depending upon where
we want those pools of light, and where we
| | 05:29 | want those specular highlights.
| | 05:31 | But, as we add more area lights, the
render times are going to increase.
| | 05:36 | Area lights are also dependent upon their size.
| | 05:40 | So, if we minimize our Render view,
let's close out the Attribute Editor, and
| | 05:45 | let's go back to Perspective.
| | 05:46 | Area lights can be scaled.
| | 05:50 | So I can scale them in a singular
direction, or I can scale them overall.
| | 05:56 | Keep in mind, as I scale my light, we are
going to be throwing more light onto the object.
| | 06:02 | More light means longer render times.
| | 06:05 | But, there's also a fine balance
between the scale, the coverage, and the
| | 06:09 | intensity, as well as the render times.
| | 06:12 | Take some time to create different
light types, taking time to change color,
| | 06:16 | shadows, and intensity to see
the different results you get.
| | Collapse this transcript |
| Lighting with low quality settings and proxies| 00:01 | Rendering multiple test renders
when lighting takes a lot of time.
| | 00:04 | Here are some workflow tips to
help you speed up that process.
| | 00:07 | Let's go ahead and open up
our Render Settings window.
| | 00:11 | Down in the Image Size,
we're rendering HD 720.
| | 00:14 | I don't want to do test renders
in this size.
| | 00:18 | What I want to do is render something
about half that, or a third of that; make
| | 00:23 | the process a lot quicker.
| | 00:24 | What we want to do is let's close out of
our Render Settings window, and this time
| | 00:28 | we're going to open up our Render View.
| | 00:31 | Under Options > Test
Resolution, I've selected 50%.
| | 00:36 | So I'm going to be rendering 50% of
whatever is in my Render Settings window.
| | 00:42 | We're going to be rendering 50% of HD 720.
| | 00:46 | Let's go ahead and do a
quick render; see what we get.
| | 00:50 | Let's move our Render View off to
the side, and let's open up our Render
| | 00:53 | Settings window again,
| | 00:55 | and this time we're going
to go to our Quality tab.
| | 00:58 | First thing we want to do is we want to set
our Sampling mode to something like Custom.
| | 01:03 | That way, our Min Sample, and our Max Sample
can now be adjusted independently of each other.
| | 01:10 | So let's set our Min Sample Level to 0,
and we'll keep our Max Sample Level to 1.
| | 01:15 | Next, let's scroll down, and we're
going to open up our Raytrace Settings.
| | 01:19 | I'm going to keep our Raytrace Settings
down to its minimum, which is 1, 1, and 2;
| | 01:25 | Reflections: 1, Refractions: 1,
| | 01:27 | and Max Trace Depth to 2.
| | 01:31 | I can always change those higher
as we prepare for our final render.
| | 01:35 | Finally, let's go to our
Indirect Lighting tab.
| | 01:38 | Let's turn on our Final Gathering, and we're
going to leave these all at minimum settings;
| | 01:43 | our Accuracy to 50, our Point Density
to 1, and our Point Interpolation to 5.
| | 01:50 | Now let's do one more render.
| | 01:52 | Let's save this current render in
the buffer, and we're going to redo our
| | 01:56 | previous render, which is our shot camera.
| | 02:00 | So now we can see some of the effects
of turning on final gather. Let's scrub
| | 02:04 | between the two images.
| | 02:07 | Another trick I like to do to speed
the render process up, especially when
| | 02:10 | working with very large scenes or CAD data is
to create a low resolution proxy scene file.
| | 02:17 | We still get the basic
shape, but not all the detail.
| | 02:20 | There is a great way to initially set
up the lighting, then we swap out the
| | 02:25 | low resolution proxy for the higher
resolution final model, which is what
| | 02:29 | we're looking at here.
| | 02:30 | So let's go ahead and do that.
| | 02:31 | I'm going to minimize my
Render View window.
| | 02:33 | Let's take a look at the low
proxy file I have saved already.
| | 02:37 | So, we notice in the low proxy file,
we don't have a lot of detail, for
| | 02:41 | instance, like on the wheels;
| | 02:42 | we don't have all the rims,
and the hub caps.
| | 02:45 | Also notice that the model
is much more faceted.
| | 02:47 | That's because it's not smoothed.
| | 02:49 | Smoothing adds a lot more geometry to
the model, which takes time to render.
| | 02:54 | So, we are going to want to bring this
low proxy model back into our shading
| | 02:59 | file, and then light that, and then
we can swap back out the low proxy file
| | 03:04 | for a high-res model.
| | 03:06 | So, let's go back to our shading file.
| | 03:09 | We're going to open up our Reference Editor.
| | 03:12 | Let's move this off to the side, so we
can kind of see what's happening here.
| | 03:16 | Let's turn off our high-resolution model.
| | 03:19 | Now we're going to browse for our low-res
proxy in our assets directory, and
| | 03:25 | here it is: loresProxy.
| | 03:26 | So now in our Reference Editor, we can
see we have both the high-res, and the
| | 03:32 | low-res, and simply by clicking on
these checkboxes, I can go between the two.
| | 03:37 | Also notice that the low-res
proxy is only gray-shaded.
| | 03:40 | This is great, because I only want to be
lighting to a gray-shaded car for now.
| | 03:45 | I'm only interested in
light coverage and values.
| | 03:49 | I'm not really interested right now in how
the light is interacting with the shaders.
| | 03:52 | So let's go ahead, open up our Render
View window, put this one in our render
| | 03:57 | buffer, and let's do one more render.
| | 04:01 | That render was much faster than
having our fully shaded car in the scene.
| | 04:06 | Let's minimize that.
| | 04:08 | Let's go ahead and open up our
Reference Editor one more time, and now
| | 04:12 | let's turn on our high-resolution model,
turn off our loresProxy, and now we
| | 04:19 | can continue lighting.
| | 04:21 | Notice too that all our shader assignments
are still assigned to the proper geometry.
| | 04:26 | As long as the name of our
objects do not change, those assignments
| | 04:30 | will continue to hold.
| | 04:31 | So, these are some good ways to make
your lighting workflow quite a bit faster.
| | 04:36 | Now we need to add more area lights
to our scene to finish off the lighting
| | 04:40 | of our vehicle.
| | Collapse this transcript |
| Working with area lights| 00:00 | Now that we know what kind of light
types we are going to be using -- the area
| | 00:04 | lights -- let's start lighting.
| | 00:06 | Let's go back into our
Create menu > Lights > Area Light.
| | 00:11 | We need to scale and rotate this
light in the place, taking advantage of our
| | 00:16 | background image analysis from chapter 1,
as well as looking at our IBL in our scene.
| | 00:22 | So we go to Panels > Perspective.
| | 00:26 | Let's dolly in, and tumble and track out,
hit the W key; let's move the light out.
| | 00:32 | Let's swing around here.
| | 00:33 | We notice in IBL that there is a lot
more light coming from this general
| | 00:38 | direction, because this light is going
to be our key light, mimicking the sun.
| | 00:42 | Back to panels, and Look Through Selected,
| | 00:45 | and let's back this camera out.
| | 00:48 | We are actually looking
through our light right now.
| | 00:51 | Now back to Panels > Perspective.
| | 00:55 | Another nice little trick I
can do is I can hit the T key.
| | 00:59 | That gives us another manipulator.
| | 01:00 | This second manipulator is actually
our look at point, where the light is
| | 01:04 | going to be following.
| | 01:06 | So let's hit our spacebar.
| | 01:08 | We look in our top view.
| | 01:09 | This is just an easy way in
which to place the look at point.
| | 01:13 | So we are looking down; I want to get
it centered in the car, and maybe little
| | 01:18 | to lower here in our front view.
| | 01:20 | Spacebar, so it goes full screen again.
| | 01:24 | Notice that on the area light, there
is a little toggle that comes out.
| | 01:28 | That indicates the direction of the light.
| | 01:31 | We want the light to be
shooting towards the car,
| | 01:33 | so we have to be aware of that toggle.
| | 01:37 | Now let's move the light more in
place where our sun is coming from.
| | 01:44 | That looks pretty good.
| | 01:46 | Let's hit our R key,
and we can scale the light up.
| | 01:50 | Maybe make it a little bit wider
to get more coverage of the car.
| | 01:54 | Let's go back to our
Perspective View, and our shot camera.
| | 01:58 | Now let's do a render.
| | 02:00 | Looking pretty good so far, but there is
still quite a bit more work to be done.
| | 02:05 | Let's minimize our Render View.
| | 02:06 | Our light is selected.
| | 02:08 | Let's go ahead and isolate the light, so we
are not getting any influence from the IBL.
| | 02:14 | Let's open up our Render Settings window,
Indirect Lighting tab > Image Based Lighting.
| | 02:20 | Let's scroll down to our Color Gain.
| | 02:23 | If you will recall from a
previous lesson, we set our value to 4.
| | 02:26 | Let's set our value to 0,
| | 02:29 | so now we will have no influence from our IBL.
| | 02:34 | Let's do another render.
| | 02:37 | Let's save that into our render buffer.
| | 02:39 | So now we are only seeing just the effects
of the light, without the influence of the IBL.
| | 02:45 | Let's go ahead and take a
look at the actual light itself.
| | 02:50 | So let's close out the
Render Settings window for now.
| | 02:53 | Let's make sure the
light is selected right here.
| | 02:55 | Ctrl+A to open up the Attribute Editor.
| | 03:00 | Now we are looking at some of the
light parameters of our Area Light.
| | 03:04 | First thing we want to probably do is
set the color, maybe a little warmer.
| | 03:08 | I can just dial this towards warmer color here.
| | 03:12 | And then using this little icon, we can
change the color of the light, but we just do
| | 03:17 | this very sparingly.
| | 03:20 | Next, we want to change
the intensity of the light.
| | 03:22 | Right now the car looks quite a
bit dark just from that one light.
| | 03:26 | So let's crank that up, maybe even 10.
| | 03:28 | Also, let's make sure Emit Diffuse and
Emit Specular are both turned on, so we
| | 03:33 | get both diffuse and
specular highlights from our light.
| | 03:37 | Since our image is now
saved, let's do another render.
| | 03:41 | Obviously, that is bright,
| | 03:43 | so you might be tempted to adjust the
Intensity back down to a lower number,
| | 03:47 | like 2, but the reason why our light is so
bright is because we have no Decay selected.
| | 03:52 | So we are going to have to set our
Decay to at least Linear or Quadratic.
| | 03:59 | Quadratic decay rates mimics real
world decay, where light falls off at a rate
| | 04:04 | of about a quarter,
| | 04:05 | whereas Linear decay falls off at around
half, meaning every time you double your
| | 04:11 | distance, you halve the light intensity.
| | 04:15 | I find that Linear decay reduces
clipping of whites, because the falloff is
| | 04:20 | less abrupt than Quadratic.
| | 04:23 | Let's keep our Decay Rate to Linear, and
let's reset our Intensity back to 10, and
| | 04:28 | let's do another render, and see what we get.
| | 04:32 | Starting to look a little bit better now.
| | 04:34 | Let's scroll down here, and the last
parameter we are going to look at is Use Light Shape.
| | 04:40 | We want to make sure that we
are using a Rectangle light shape.
| | 04:45 | This translates the Maya area
light to use with mental ray.
| | 04:48 | Since we are using a Rectangle area
light, we need to set this to Rectangle.
| | 04:53 | This translation will ensure the light
performs according to the input parameters.
| | 04:57 | You will notice several other
shapes that area lights can be set to.
| | 05:02 | We have Discs, Sphere, Cylinder, Custom;
| | 05:04 | there is not a huge visual
difference between the shapes,
| | 05:08 | but there does seem to be
changes in the shape of the shadow.
| | 05:12 | So experiment for yourself to see
which shape might work best for you.
| | 05:16 | In the meantime,
let's set this to Rectangle.
| | 05:20 | Let's do one more render.
| | 05:22 | Now that we have our key light in our
scene file, we need to further fine-tune
| | 05:26 | it to get our desired results.
| | Collapse this transcript |
| Setting light samples| 00:00 | One of the most important parameters
we need to address when improving the
| | 00:04 | quality of our area lights are light samples.
| | 00:07 | If we were to leave our samples set
to the default settings, we get a lot
| | 00:14 | of grain and noise.
| | 00:15 | Here is a render that I did with our
area light, which is our key light, set to
| | 00:19 | our default settings.
| | 00:20 | Notice quite a bit of
noise and grain in the image.
| | 00:24 | Let's look at the sample settings get a
better idea on how to fix these issues.
| | 00:28 | Minimize the render window.
| | 00:30 | Let's select our area light, and we're going
to hit Ctrl+A to bring up the parameters.
| | 00:36 | The area light sample settings are
under the Area Light rollout, and we set our
| | 00:42 | light shape to a Rectangle.
| | 00:44 | The default settings are 8 for High Samples.
| | 00:47 | The High Sample Limit is set to 1, and
the Low Samples are set to 1 as default.
| | 00:52 | High Samples are the amount of samples
that get shot toward the light when an
| | 00:57 | I-ray strikes an object.
| | 00:59 | This is the most important level of quality.
| | 01:02 | The larger and closer the area
light, the more samples you need.
| | 01:07 | The High Sample Limit can be
set lower than the High Samples.
| | 01:11 | Once this number of combined reflections
and refractions is exhausted, the sample
| | 01:16 | can draw fewer samples, as
defined by the Low Samples setting.
| | 01:20 | The Low Samples are the amount of
samples to draw from, a sample taken after the
| | 01:26 | number of reflections and
refractions in the high sample.
| | 01:29 | If Visible is checked, the area
light will be visible in the render.
| | 01:34 | For our purposes in this course, we
want to make sure that the Visible
| | 01:37 | checkbox is unselected.
| | 01:39 | If it is selected, then we
actually see the shape of the light.
| | 01:43 | We don't want to see that,
| | 01:44 | so make sure that Visible is unselected.
| | 01:48 | Changing the Area Light samples reduces
grain, not only the shadows, but in the
| | 01:54 | highlights, and lit areas as well.
| | 01:56 | Let's reset the High
Samples to something like 64.
| | 02:00 | Let's set the High Sample Limit to 32,
and the Low Samples to something like 16.
| | 02:06 | So basically, it's a cascading array of numbers.
| | 02:10 | The High Sample Limit is typically
the highest, and the Low Samples is
| | 02:13 | typically the lowest.
| | 02:15 | So now let's do another
render and we can compare.
| | 02:18 | So let's open up a render view.
| | 02:19 | This time let's create a render region.
| | 02:22 | So I'm going to just select that portion of
the car, and now we're going to hit Render Region.
| | 02:29 | Let's save this render in our render
buffer, and now we can compare the two renders.
| | 02:33 | This was our render with the samples
set to default, and this is our new render
| | 02:38 | with a higher sample limits.
| | 02:41 | If we look at the difference,
we've eliminated the grain.
| | 02:45 | Let's go back to the light in our
Attribute Editor, and these are some of the
| | 02:49 | production quality settings I typically use.
| | 02:52 | So we can set our High Samples to
something like 256, our High Sample Limit
| | 02:58 | maybe to 64, and our Low Samples we
can either do 64, or maybe even 128.
| | 03:05 | I would suggest that you play around
with these numbers to see what best suits
| | 03:09 | your needs to get the grain and the noise
reduced, but also keeping render times low.
| | 03:15 | But for a photorealistic image,
you need shadows,
| | 03:18 | so let's next look into how to set up shadows.
| | Collapse this transcript |
| Using raytrace shadows| 00:00 | In real life, whenever we have light
and an object, we usually have a shadow.
| | 00:05 | Right now we don't have shadows on.
| | 00:08 | Let's look at some of the shadow
parameters we need to address with our area lights.
| | 00:12 | So, if we select our area light, and we
hit Ctrl+A, we'll bring up the parameters
| | 00:17 | of the selected object.
| | 00:19 | Let's scroll up to Shadows.
| | 00:22 | Our first parameter is our Shadow Color.
| | 00:25 | I generally leave the Shadow Color to
Black. With final gather on, it will add
| | 00:30 | indirect lights to our scene,
lifting shadow color by default.
| | 00:34 | If our background plate that we shot
has lighting that shows very little
| | 00:38 | shadow detail, we can simply increase
the value of the shadow color. We simply
| | 00:42 | select the Shadow Color,
and increase the value.
| | 00:47 | You'll notice that very small
increments make a big difference,
| | 00:50 | so I typically leave
this to a very small number.
| | 00:53 | So let's bring it back to black.
| | 00:54 | We're going to render with
a black shadow color.
| | 00:58 | Next we have Depth Map Shadows.
| | 01:01 | Depth map shadows are
generally not used when ray tracing.
| | 01:06 | Depth map shadows are a type of shadows
that are rendered out, and saved to disk,
| | 01:09 | so you actually have a
physical shadow map file.
| | 01:13 | Those shadow maps are then
mapped back into the light.
| | 01:15 | Since we're ray tracing, Use Depth
Map Shadows are not going to be in use.
| | 01:22 | So let's close that pulldown.
| | 01:24 | Now we are going to use Raytrace
Shadow Attributes, and we're simply going to
| | 01:27 | Use Ray Trace Shadows.
| | 01:30 | Let's take a look at render,
and see what we get.
| | 01:33 | We can see the shadows affecting the
areas of the wheels, as well as the tires,
| | 01:37 | creating shadows on the body of the car.
| | 01:40 | We can easily control the shadow quality
by the amount of rays, and the depth limit.
| | 01:46 | I typically like to keep
these to default; 1, and 1.
| | 01:50 | We can open up our Render settings.
| | 01:53 | In the Raytracing pulldown, in the
Quality tab, there's a Shadow quality
| | 01:57 | setting right here.
| | 01:58 | This is a global quality setting.
| | 02:00 | This global quality setting will set
the shadow quality overall to all our
| | 02:06 | lights in our scene.
| | 02:08 | I typically set it to 2, but
let's not deviate too far from that.
| | 02:13 | Now that we know how to manage our lights,
next let's add some additional lights
| | 02:18 | to accentuate the body lines, and to
better integrate the car to the plate.
| | Collapse this transcript |
| Lighting the body lines| 00:00 | We have our key light and our
HDRI starting to get dialed in,
| | 00:03 | but looking at our render, I still want
to see more body lines, and the concept
| | 00:07 | car more integrated into the plate.
| | 00:10 | What we're going to have to do is we are
going to have to create couple new lights.
| | 00:14 | The first one is going to be an
area light that is just going to
| | 00:18 | accentuate those body lines.
| | 00:19 | So let's minimize our render view.
| | 00:20 | Let's go into to Panels > Perspective,
| | 00:22 | then select our key light; Ctrl+H to hide.
| | 00:26 | Create > Lights > Area Light.
| | 00:29 | Hit the number 4 on our keyboard,
and then the letter W. 4, just so we can
| | 00:35 | turn off hardware shading.
| | 00:36 | Kind of easier to see it.
| | 00:39 | Lets hit E, rotate the
light, and now R to scale it.
| | 00:44 | We're going to get it nice and narrow,
and really long. W key, and now let's
| | 00:49 | just move into place.
| | 00:51 | Something like that.
| | 00:54 | Let's hit the spacebar.
| | 00:56 | We're going to go into the top view.
| | 00:57 | Just rotate it, so it's in line with the car.
| | 01:00 | Something like that.
| | 01:01 | Middle-mouse button,
perspective view, spacebar;
| | 01:06 | now let's Look Through Selected.
| | 01:07 | This is always very helpful.
| | 01:11 | Get much closer on it; kind
of get a downward angle on it.
| | 01:15 | Something like that.
| | 01:17 | Panels > Perspective.
| | 01:21 | Now let's scale the light a little bit
longer, and maybe a little bit over too,
| | 01:24 | so we are getting the whole car.
| | 01:26 | Let's go ahead and open up our
Attribute Editor for our selected object.
| | 01:32 | We're going to use a Rectangle light.
| | 01:35 | Let's turned on Ray Trace Shadows, and
let's turn on Linear Decay, and let's crank up
| | 01:42 | our Intensity, maybe to around 5.
| | 01:45 | Close out of our
Attribute Editor for now.
| | 01:47 | Back to Panels > shot camera, and
let's open up our Render View.
| | 01:53 | Let's go ahead and save this render
in our render buffer, and let's just
| | 01:59 | select the car here.
| | 02:01 | All we have on our scene is just
the IBL, and our new body lines light.
| | 02:06 | So now let's render the region.
| | 02:09 | So, let's kind of compare the two.
| | 02:11 | What we need to do,
if we hit the Ctrl+A button,
| | 02:16 | we're going to get our Attribute Editor,
and we're going to want to set our High
| | 02:20 | Samples to some thing like 64,
because we're getting some noise in here.
| | 02:24 | High Sample Limit to 32, and our
Low Samples, maybe to 16, and then also
| | 02:31 | let's rename this light.
| | 02:33 | Maybe we'll called bodyLines.
| | 02:36 | Now that we have an area light that
accentuates the body lines of car, we still
| | 02:40 | need to add a third area light behind
the car that is going to accentuate the
| | 02:46 | back of the car, and act as a
bounce light from the rocks behind.
| | Collapse this transcript |
| Adding a bounce light| 00:00 | So, the next step is we need to add some
bounce light to make it feel as though
| | 00:04 | the light is bouncing off
the rocks from behind.
| | 00:07 | This is frequently used by photographers
to really integrate an object into its
| | 00:12 | surroundings, and we kind of
want to the same thing in CGI.
| | 00:15 | So let's go ahead and do that.
| | 00:17 | Let's minimize our Render View, select
our bodyLines area light, and Ctrl+H to
| | 00:22 | hide it, and now let's go ahead
and go to Create > Lights > Area Light.
| | 00:30 | Panels > Perspective. So let's move the
area light to the back of the car this time.
| | 00:38 | This is the light that's coming off the
rocks from behind the car, and I am just
| | 00:43 | going to manipulate the light, moving
it, scaling it, rotating it into place.
| | 00:49 | Let's hit E to rotate the
light, and now R to scale it.
| | 00:53 | We are going to get it nice
and narrow, as we can see here.
| | 00:56 | Now let's go into Panels >
Look Through Selected.
| | 00:59 | Let's get a little bit higher on
the car; center it in frame.
| | 01:03 | Let's go back to Panels > Perspective.
| | 01:07 | Bring up our Attributes for the light;
select Ctrl+A. We are going to set the
| | 01:12 | Decay Rate to Linear.
| | 01:14 | Shadow Color is to black, by default.
| | 01:17 | Use Ray Trace Shadows, and we
have to select Use Light Shape,
| | 01:22 | so mental ray knows that the area
light that we want is a Rectangle.
| | 01:27 | Since our Decay Rate is Linear, let's
really bring up that Intensity, maybe to
| | 01:31 | around 15, and let's go ahead back to
Panels > shot camera, and let's do a render.
| | 01:40 | Save that one in our buffer.
| | 01:41 | Make sure this time, though, that
we are rendering the shot camera.
| | 01:47 | There's a couple things that
we are going to have to address.
| | 01:50 | We are seeing quite a bit of noise here,
which is an artifact of our specular
| | 01:54 | highlight, and we're going to want to
change the color of the light to more
| | 01:58 | closely match that of the background.
| | 02:01 | So let's just move the Render View out
of the way. With the area light selected,
| | 02:07 | we are going to hit Ctrl+A to
bring up the Attribute Editor.
| | 02:10 | In order to get rid of that specular
noise, we are just going to simply select
| | 02:14 | Emit Specular off.
| | 02:16 | So now the area light is
only going to emit just diffuse.
| | 02:19 | Let's bring up the Intensity, maybe to
around 20, and finally, with our Render
| | 02:24 | View open, we can select the color
swatch, and in here there is a little color
| | 02:29 | picker, and let's go in here and
we can select different areas.
| | 02:33 | As you can see, the color now
matches where I just selected.
| | 02:37 | So let's go back to the color picker.
| | 02:39 | Let's pick, maybe, a lighter area.
There we go.
| | 02:41 | That looks pretty good.
| | 02:43 | Let's put this one into our buffer.
| | 02:46 | Now let's do another
render, and see what we have.
| | 02:49 | That's starting to look pretty good.
| | 02:51 | We are starting to get some
light wrap from behind the car.
| | 02:54 | Let's compare it to our previous
render, and we got rid of a lot of that
| | 02:57 | specular noise as well.
| | 02:58 | So the last step we want to do is we
want to actually change the name of light,
| | 03:03 | so each light in our scene,
we know what they're called.
| | 03:06 | With the light selected, let's go over
here to the Channels box, and let's just
| | 03:11 | call this bounceLight.
| | 03:12 | So, if you have lit objects from
behind, make sure you add bounce lights to
| | 03:17 | further enhance the realism of your images.
| | Collapse this transcript |
|
|
4. mental ray RenderingUsing render layers| 00:00 | Since we're going to be rendering
output passes, like diffuse, specular, and
| | 00:05 | reflection, we need to create render
layers to tell Maya that we want those
| | 00:09 | passes rendered exclusively
for a specific set of geometry.
| | 00:13 | Each render layer can then be composited
separately, giving you much more control
| | 00:18 | in your final composite.
| | 00:20 | If we go into our Perspective view, we
can add geometry a couple different ways.
| | 00:25 | We can either select everything
here in the viewport, or we can go to
| | 00:30 | Window > Outliner, and then we select the
geometry, and then add the render layer that way.
| | 00:36 | Let's do it in the viewport instead.
| | 00:38 | I am going to just select my geometry in here.
| | 00:42 | Then I am going to select this icon,
which basically means we are going to add
| | 00:47 | the selected geometry to a new render layer.
| | 00:50 | Next, we are going to
select the new render layer.
| | 00:53 | We are going to double-click, and inside we
are going to give our render layer a name.
| | 00:59 | In this particular case, let's call it Car.
| | 01:01 | Let's switch back to our masterLayer.
| | 01:03 | Notice that we don't have our IBL
icon attached to our new render layer.
| | 01:09 | Let's go back to our new render layer, and we
can add any geometry to our new render layer.
| | 01:16 | So how we do that is we simply right-click,
and we say Add Selected Objects.
| | 01:22 | Now our IBL icon is
associated with that render layer.
| | 01:26 | Had we not done that, and we rendered
our Car render layer, we would not be
| | 01:30 | getting the effects of the
IBL on that render layer.
| | 01:33 | The next step that we want to do is
we want to go into our Render Settings
| | 01:38 | window, and under the Common tab, we
need to rename our file name prefix.
| | 01:44 | So let's right-click in the
area, and this time we are going to
| | 01:48 | select RenderLayer.
| | 01:50 | As you can see, Maya is smart enough to
give us the correct path of where our
| | 01:55 | render layer is going to be going, and
what our file name is going to be called.
| | 01:59 | Our file name is now going to be called Car.tif,
which is the same name as our render layer.
| | 02:06 | Another thing we can do is we can
actually instruct Maya to render this
| | 02:11 | RenderLayer into its own
folder outside of the images folder.
| | 02:15 | For instance, I can now say
Car, add a forwardslash, hit Enter;
| | 02:21 | now the path name changes.
| | 02:23 | So now we are going to be rendering to
images, a new directory called Car, and
| | 02:29 | then the file name called Car.tif.
| | 02:31 | This just gives us another added
layer of control for more organization.
| | 02:36 | This is very good when multiple
artists are working on a single asset.
| | 02:39 | Their outputs do not want to be
populating the same directory.
| | 02:44 | Now that we have singled out our vehicle
to render on its own, we need to render
| | 02:48 | out passes associated with this render layer.
| | Collapse this transcript |
| Setting up render passes| 00:00 | One of the great benefits of using
render layers is that we can now render
| | 00:04 | unique passes associated
with the selected render layer.
| | 00:07 | This gives us a lot of flexibility
in our composite, where we can make
| | 00:11 | adjustments to a single pass.
| | 00:13 | Let's take a look at how we
can create these render passes.
| | 00:16 | Here in Nuke, I'm going to show
you what these passes actually look
| | 00:20 | like separated out.
| | 00:21 | So here's our car render layer that
we rendered out, and here is our ambient
| | 00:26 | occlusion which I call AO.
| | 00:28 | I'm simply hitting the number 1 button,
so our viewer is now viewing that node.
| | 00:33 | I can also just grab the Viewer
node, and move it to a different node.
| | 00:36 | So now we're looking at our Indirect
pass, Specular, Reflection, and Refraction.
| | 00:44 | If we were to add all these up using the
Merge add node, we would end up with the
| | 00:49 | same render that we started with.
| | 00:51 | Let's go back to Maya, and see
how I output these render passes.
| | 00:56 | Here in Maya, I have to make sure, first
and foremost, that my Car render layer is
| | 01:02 | selected. That way, when I go into my
Passes tab, any associated passes I add will
| | 01:08 | be added to my Car render layer.
| | 01:12 | Let's go back into our Render
Settings, and Create new render pass.
| | 01:17 | Now we have this big list that comes up.
Let's go ahead and find those passes
| | 01:21 | that I rendered out.
| | 01:22 | First one is Ambient Occlusion, and now
let's scroll down; we can use this side
| | 01:27 | scrollbar here. Holding down the Control
button, I'm adding a selection; in this case,
| | 01:33 | Diffuse. Let's go ahead and add Indirect.
Let's continue down. Let's go ahead
| | 01:38 | and add Reflection,
Refraction, and finally, Specular.
| | 01:44 | And we can say Create and Close.
| | 01:47 | Since these Render Passes are up in here
in the scene selection, we still have to
| | 01:51 | associate them with the render layer.
| | 01:54 | So let's select this button right
here, which associates the selected render
| | 01:58 | passes to that render layer.
| | 02:01 | Next, let's go back to our Common tab.
| | 02:04 | Right now we're only rendering out
images, car.tif. If we want to render out
| | 02:09 | separate render passes, we simply
right-click; go down to our render pass name,
| | 02:16 | let's insert a forward slash, and hit Enter.
| | 02:20 | Now we're rendering to Concept_Car/images,
to a directory called Car; within that
| | 02:27 | directory, we're going to be getting our
associated render passes. Let's go ahead
| | 02:32 | and open up our Hypershade window. Go
to Window > Rendering Editors > Hypershade.
| | 02:40 | Notice that each of these shaders is
a mia_material_x_passes shader. This is very
| | 02:45 | important. If these materials don't
have the x passes truncated on to the end,
| | 02:52 | then when we render out our render
passes, these passes will not render.
| | 02:58 | So we select mental ray, we scroll down,
and notice several of the shaders have
| | 03:06 | passes associated to them.
| | 03:08 | In this particular case, we're
using the mia_material_x_passes.
| | 03:12 | Now we know that our passes will be
rendered out when anything is assigned to
| | 03:16 | that object with that shader.
| | 03:19 | To properly composite these passes, we
must make sure they have the highest
| | 03:23 | bit depth available,
| | 03:24 | so let's examine how to
make these passes 32-bit.
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| Creating 32-bit files| 00:00 | 32-bit images are great at showing
values brighter than white, and subtle
| | 00:04 | variations in hue and tone.
| | 00:06 | 32-bit images contain millions more
colors per pixel than 8-bit and 16-bit images.
| | 00:12 | Let's compare this in Nuke.
| | 00:14 | So, here is my rendered car,
and my associated passes.
| | 00:20 | Let's use our specular pass to show
the comparison between 32-bit, and 8-bit.
| | 00:26 | Let's view our specular pass here in
our 32-bit, and here I rendered out a
| | 00:30 | separate 8-bit pass that I'm
only going to be using here for
| | 00:34 | demonstration purposes.
| | 00:35 | Already, you can see a huge difference,
not only in the brightness of the pass,
| | 00:42 | but also in how the brights are
maintaining their highs, and the darks
| | 00:47 | maintain their lows.
| | 00:49 | So, I simply select my node, I'm hitting 1,
I'm on the specular pass for my 32-bit,
| | 00:55 | and here on my 8-bit, I'm selecting 2,
and I'm just toggling between the two.
| | 01:01 | To show you a little more in depth
what I'm talking about, let's go ahead and
| | 01:04 | add a glow node onto each of these images.
| | 01:07 | So I'm going to hit Tab. Let's type
in Glow, and let's just view that first
| | 01:13 | in our 32-bit image.
| | 01:14 | So now we can kind of see the difference.
| | 01:15 | I'm going to go between 1 and
2 here; so we add some glow.
| | 01:20 | And let's go ahead and add some color;
make it pretty saturated. Let's close that out.
| | 01:28 | What I'm going to do is I'm going to
simply Ctrl+C, Copy that node. I
| | 01:32 | select my Reformat, because I
rendered it out a little bit smaller than
| | 01:35 | HD. Ctrl+V for Paste.
| | 01:38 | And now I'm going to put
that on my Render buffer 2.
| | 01:42 | So now my glow is on number 1 for my 32-bit
image, and number 2 for my 8-bit image.
| | 01:48 | This just really further enhances the
idea that when you add color corrects,
| | 01:54 | and other operations, like glow, 32-bit images
are very important to render out from Maya.
| | 02:00 | So let's go into Maya, and see how I did that.
| | 02:02 | Let's open up our Render Settings window,
go to our Passes tab, and our Associated
| | 02:09 | Passes, to our Car render layer.
| | 02:12 | For our ambient occlusion pass, we do
not have to set this to 32-bit; it's just
| | 02:16 | simply a black and white image that
we're going to multiply into our comp.
| | 02:20 | But for our diffuse, our indirect,
our reflection, our refraction, and
| | 02:24 | our specular we will.
| | 02:26 | Let's double-click each render pass, and
change them individually. Under Frame Buffer Type,
| | 02:32 | let's open up the rollout, and select
32-bit Float. Indirect, reflection,
| | 02:43 | refraction, and finally, specular.
| | 02:48 | This only affects the render passes.
There might be some other things that you
| | 02:53 | render in your scene other than the passes.
| | 02:56 | Now we have to set the
entire Maya file to render 32-bit.
| | 03:00 | Let's go to our Quality tab, let's
scroll down to the bottom to the Framebuffer.
| | 03:07 | Let's open up that rollout, and under
Data Type, right now any other elements in
| | 03:12 | our scene would render at 8-bit. To
ensure that everything renders in 32-bit,
| | 03:17 | let's scroll down, and under
RGBA (Float) 4x32 Bit, let's select that.
| | 03:24 | RGBA (Float) 4x32 simply means four channels,
the R, G, B, and A, will now render at 32-bit.
| | 03:33 | So when rendering your render layers
and passes, make sure your settings are
| | 03:38 | at 32-bit.
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| Adjusting the render quality settings| 00:00 | A quick word about quality
level settings in mental ray.
| | 00:04 | Notice here, I pre-rendered an
image that I have set to low quality.
| | 00:10 | Unfortunately, rendering low quality
produces aliasing artifacts, jagged edges,
| | 00:15 | as you can see here in the image.
| | 00:16 | This is okay, because I'm not actually
going to be rendering out and saving
| | 00:20 | these images for final output, but
what I am going to be doing is just doing
| | 00:24 | quick test renders.
| | 00:25 | I'm going to show you those settings,
and then I'm going to show you how to get
| | 00:29 | better quality settings for final output.
| | 00:31 | So if we go into our Render Settings
window, here in the Quality tab, we have to
| | 00:35 | make sure that are Sampling mode is set
to Adaptive, which simply means that both
| | 00:39 | the max and min samples
are going to be constrained.
| | 00:43 | So for low quality settings, -2; Max, 0.
Maybe for high quality, I typically go with
| | 00:50 | something around 0, 2. Anti-aliasing
Contrast threshold; low quality settings, .1.
| | 00:57 | When I want to render my
final quality settings, .05.
| | 01:00 | Multi-Pixel Filtering, low quality
settings, I set to Box Filter Size in X 1, and
| | 01:11 | the Filter Size in Y 1.
| | 01:14 | For final renders, let's set that to
Mitchell, which automatically sets the
| | 01:19 | Filter Size to 4, 4.
| | 01:21 | Scrolling down here, Raytracing;
Reflections 1, Refractions 1, Max Trace Depth 2.
| | 01:27 | Final quality settings, I typically
do something around 2, 2, and 4. Okay.
| | 01:34 | Now, if we take a look real quickly
at the difference between low quality
| | 01:38 | settings, and a high quality
setting, that would be our difference.
| | 01:43 | But notice render times
are quite a bit higher.
| | 01:47 | We go from around 48
seconds to about 5 minutes.
| | 01:50 | Let's jump over here real
quick to our Render Passes.
| | 01:54 | When we do test renders, we want to
make sure our Render Passes are set off,
| | 01:58 | especially when we are rendering batch
mode, because when we render in batch
| | 02:02 | mode, that's when the render passes
are output.
| | 02:04 | So there is couple of
different ways we can turn these off.
| | 02:07 | One way is we Shift+Select all the
passes, and we can de-associate the passes.
| | 02:13 | Now they're not going to be rendered.
| | 02:14 | Let's put them back down into
the Associated Passes section.
| | 02:18 | The second way we can do that
is we select Shift+Select again,
| | 02:22 | right-click > Set Non-Renderable.
| | 02:24 | Just remember that when you are ready to
batch render, or render on a render farm,
| | 02:29 | we have to make sure that we are
going to set these back to Renderable.
| | 02:32 | So that's just to real quick overview
on how to get our render settings both to
| | 02:36 | a low quality, and high quality, and
hopefully save you some time in the
| | 02:40 | rendering process.
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| Explaining final gathering| 00:00 | We need to talk a little bit
about final gather.
| | 00:02 | Final gather in mental ray is like a
global illumination cheat when global
| | 00:08 | illumination is not set.
| | 00:10 | Final gather is mental ray's method to
calculate diffuse reflections, where light
| | 00:15 | bounces from non-reflective surfaces.
| | 00:18 | This gives a render a lot more
realistic look, especially when large
| | 00:22 | light sources are used.
| | 00:24 | As we've seen, I am using large
light sources in our area lights.
| | 00:27 | So this is just another
great reason to use area lights.
| | 00:31 | So let's go ahead and look
at our final gather settings.
| | 00:34 | With our Render Settings window open,
we're going to go to our Indirect Lighting
| | 00:38 | tab, and we're now going to go under the
Final Gathering rollout. Let's scroll down.
| | 00:44 | Open this up.
| | 00:45 | What I have here are my
lower quality settings.
| | 00:48 | So here in our Render View,
these are my lower quality settings.
| | 00:53 | We are going to increase our Accuracy,
which is how many rays are used during
| | 00:59 | the render of the final gather.
| | 01:01 | Higher values are going to improve quality.
| | 01:03 | So let's go from 50, which is our lower
quality setting, to something around 200.
| | 01:09 | Next, let's look at Point Density.
| | 01:11 | The more final gather
points in the scene, the better.
| | 01:14 | So, the Point Density increases
the amount of final gather points.
| | 01:19 | Our low quality setting is .5.
| | 01:21 | Let's set our higher quality
setting to maybe around 1.
| | 01:26 | The Point Interpolation
increases to smooth the render.
| | 01:30 | It is not as accurate as increasing
your Accuracy, but it is a much faster way
| | 01:35 | to improve the quality.
| | 01:36 | So lower quality setting, I
typically leave it to around 5.
| | 01:41 | Bring that up to maybe around
30 for a higher quality setting.
| | 01:45 | So these are my high quality settings now.
| | 01:47 | Lastly, let's look at the Final
Gathering Quality rollout, and we notice that
| | 01:52 | there's a Filter number here.
| | 01:54 | Always set that the final
gather quality filter to 1.
| | 01:57 | As you increase this, less spots
will be visible in the final render.
| | 02:02 | Now, I keep this setting to 1 for
both low and high quality renders.
| | 02:07 | By increasing the number doesn't
necessarily increase the time of the render,
| | 02:10 | so let's just keep that at 1.
| | 02:13 | Experiment with different settings, and
see what works for you, but the settings
| | 02:16 | I've described above should
work really good for this course.
| | 02:20 | Our last step in setting up our
renders is to add ambient occlusion.
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| Rendering the final image| 00:00 | A quick word about our file format
before we render out our final lighting file.
| | 00:05 | We have all our lights, geometry, and IBL
assigned to a unique render layer called Car.
| | 00:12 | Right here is our render layer Car,
and our lights, our geometry, and our IBL
| | 00:17 | are assigned to that render layer.
| | 00:20 | Let's open up our Render Settings
window, or just bring that forward; it's
| | 00:24 | already opened up, and we have to
change our image file format to OpenEXR, so
| | 00:29 | let's scroll down, and
select OpenEXR file format.
| | 00:34 | Make sure the File name
prefix is set to RenderLayer only.
| | 00:38 | Right now I have RenderLayer/RenderPass,
so let's clear out that selection,
| | 00:42 | and right-click, and we're going to
scroll down here, and say Insert layer
| | 00:46 | name <RenderLayer>.
| | 00:48 | We have to make sure that the File
name prefix is set to RenderLayer only,
| | 00:52 | because if we include the RenderPass,
then when we batch render, you'll only get
| | 00:58 | passes into separate files.
| | 01:01 | You'll find it quite a bit easier to
have a single .exr file, and then extract
| | 01:06 | those passes manually in Nuke,
| | 01:08 | but you should try both ways
to see which works best for you.
| | Collapse this transcript |
|
|
5. Creating Secondary PassesRendering matte passes| 00:00 | In order to color correct, or make
changes to parts of the vehicle in Nuke, we
| | 00:05 | need to single out bits
and pieces of the object.
| | 00:08 | To do this, we need to assign and render
individual parts of the geometry: Red,
| | 00:13 | Green, and Blue; primary colors that
can easily shuffled out to white by the
| | 00:18 | Shuffle node in Nuke.
| | 00:19 | And then we can use that as a matte to do
any number of different color corrections.
| | 00:25 | So, for example, if I want to darken
down just the paint, let me put a Shuffle
| | 00:30 | node on the paint matte that I created.
| | 00:33 | We're going to hit the Tab button, let's
type in Shuffle, and let's set this all
| | 00:39 | to red, because that's
where all my paint is.
| | 00:43 | That sets the paint to white.
| | 00:45 | Under the Grade node here, let's hit
the Tab again, and let's type in Exposure,
| | 00:50 | just to darken it up a bit.
| | 00:52 | Now let's bring our mask up to our
Shuffle, and we have the Exposure node in
| | 00:58 | our Properties, and now let's just view the
Exposure node, and bring down just the paint.
| | 01:05 | What it basically is doing is it's
isolating bits and pieces of the car, so now we
| | 01:10 | can make color changes.
| | 01:12 | Now let's go over to Maya, and I'm going
to show how I actually output those passes.
| | 01:16 | So, in Maya, what I first like to do is
let's select the entire car, and let's
| | 01:23 | create a couple of different render layers.
| | 01:26 | I think what I did is I
actually created four of them.
| | 01:29 | So we are going to double-click on each render
layer, and we're going to say M1, for Matte 1.
| | 01:34 | We're just going to our work our way up.
| | 01:39 | So we go back to our M1 render layer.
| | 01:42 | Now we open up our Hypershade window;
| | 01:44 | Window > Rendering Editors > Hypershade.
| | 01:49 | Now, for each one of these, I am going to have
to assign what I call the blackHole shader.
| | 01:53 | Let's double-click that, open up the
Attribute for that, and all it is just a
| | 01:56 | Lambert shader, and you
could put any color on it.
| | 01:59 | I like to do anything other than black,
so when I assign constant colors -- the
| | 02:04 | Red, Green, and Blue -- then you
can easily see the geometry.
| | 02:07 | The other thing I like to do is set
the Matte Opacity to Black Hole, because
| | 02:11 | that will just give us a lot
more flexibility in my composite.
| | 02:14 | So let's close out the Attribute
Editor, and so for each one of these render
| | 02:18 | layers, I'm going to just select my
geometry in here, and now let's just
| | 02:24 | right-click, Assign Material.
| | 02:25 | Let's go to M2, and assign to
selection, and then M3, and then M4.
| | 02:36 | We need to create our Surface
shaders with the constant color on there.
| | 02:41 | Notice, I already have my
green and my blue already created.
| | 02:44 | I'm going to show you what
I did in order to do that.
| | 02:48 | I just went down here to Surface Shader.
Let's make that a little bit easier to see.
| | 02:52 | Let's bring up the Attribute by double-clicking,
and under the Out Color, we just
| | 02:56 | select Red, Green, or Blue.
| | 02:58 | Well, since I don't have Red, let's
just select that one. Close that out.
| | 03:02 | So now we have all three primary colors.
| | 03:05 | So, let's go back to our M1.
| | 03:08 | Window > Outliner, let's open up our conceptcar,
and we can select, let's say, our sheetMetal.
| | 03:15 | In our Hypershade, we had it selected
to red, so we right mouse click over our
| | 03:21 | red shader, Assign Material to Selection.
| | 03:23 | Now let's go back to the Outliner.
Let's select our windows, and I believe they
| | 03:31 | were blue; right-click, assign selected.
| | 03:35 | Lastly, the little piece here in the
front, and I think we assigned that to green,
| | 03:39 | so we right-click, assign material.
| | 03:43 | So now, for each of these render
layers, we would canvas the car, and select
| | 03:49 | different pieces, just as
I have done here in Nuke.
| | 03:53 | So, for instance, on our M2 layer, I
cover the wheels. On our Matte 3 layer, I
| | 03:59 | got the little bits and pieces of the
front of the car where the headlights are,
| | 04:03 | and the trim around the windows. And
on our M4 layer, I got the interior.
| | 04:09 | So let's go back to Maya one more time.
| | 04:12 | Let's open up our Render Settings window.
| | 04:14 | What I did here is, in the File
name prefix, I make sure that we have
| | 04:19 | RenderLayer/RenderLayer, and this
simply means that each of the render layers
| | 04:25 | are going to render into a separate
directory, with its own unique name.
| | 04:30 | Under images/M1, and then M1.exr, or
whatever file extension you're using.
| | 04:37 | Also, under Features, I turned Raytracing
off, and finally, Indirect Lightning, I
| | 04:42 | turned Final Gathering off.
| | 04:44 | We don't need those when
we're creating mattes.
| | 04:47 | So the final step would be to do a batch
render to get all the render layers into Nuke.
| | 04:52 | So let's close out our Render
Settings window, and I just want to change the
| | 04:55 | Perspective to shot camera (ShotCam).
| | 04:58 | Let's just simply go up
to Render, and Batch Render.
| | 05:02 | Once I select that, we are going
to start to render with mental ray.
| | 05:07 | So that is one way to create matte passes
in Maya, and how to use them in Nuke to
| | 05:10 | isolate and color correct
parts of an object.
| | Collapse this transcript |
| Creating a ground occlusion pass| 00:00 | This is a good time for us to create
a way for the vehicle to look grounded
| | 00:04 | onto the road surface.
| | 00:05 | I like to create
two separate passes for this.
| | 00:08 | The first pass is an occlusion pass, just
for the ground, where the wheels come in
| | 00:13 | contact with the ground,
| | 00:14 | and also we see darkening
where the body is over the road.
| | 00:17 | And then the second pass
is actually a shadow pass.
| | 00:20 | But let's start with the
occlusion pass first.
| | 00:24 | I can start with any of my lighting
files, and I like to strip the file out of
| | 00:28 | the IBL, and the area lights.
| | 00:31 | So, first thing we've to do is create
a new render layer. Let's open up our
| | 00:35 | Outliner to select our geometry.
| | 00:37 | We go to Window > Outliner. Let's select the
shot camera, the concept car, and the ground plane.
| | 00:45 | Now we are going to create a new
render layer, and rename that default render
| | 00:50 | layer to something like
groundAOC; ground ambient occlusion.
| | 00:55 | Let's display our ground plane;
Display > Show > Show Selection.
| | 01:00 | Next, we're going to want to create a
shader to apply to all the geometry in the
| | 01:04 | scene. We have to go into our Hypershade,
so Window > Rendering Editors > Hypershade.
| | 01:12 | First thing we need to do is create a
Surface Shader. As you recall from previous
| | 01:16 | lessons, a surface shader is not
affected by any lights in your scene,
| | 01:19 | so it just renders flat.
| | 01:22 | Next, let's select mental ray,
and type in amb.
| | 01:27 | This will just shorten the list to
provide us a quick way to get the ambient
| | 01:30 | occlusion texture map. Let's move
this off to the side; middle mouse button,
| | 01:35 | Click+Drag over the surface
shader, and select Default.
| | 01:39 | By selecting Default, the connection will
be made to the surface shader's Out Color.
| | 01:44 | We can confirm this by double-clicking
the Surface Shader, bringing up it's
| | 01:47 | Attribute Editor, and noticing now
that the connection is made to Out Color.
| | 01:51 | If we select the arrow, that will now
show us the parameters for the ambient
| | 01:56 | occlusion texture map. We need to now assign
our shader to all our objects in our scene.
| | 02:03 | So let's push this off to the side, and
we're going to select everything in our scene.
| | 02:09 | Right-click, Assign Material To Selection.
| | 02:12 | Let's open up our Render Settings window, and
let's just make sure Raytracing is set to on.
| | 02:18 | Let's render out our scene,
and see what we get.
| | 02:20 | So, there are a couple
things we have to address here.
| | 02:24 | First, we have to make sure that the
primary visibility of the car is set to
| | 02:29 | off, so we're not seeing the car; we're
only going to get the occlusion on the ground.
| | 02:33 | Secondly, we don't want the image plane
in our final render, so we're going to
| | 02:37 | have to turn that off.
| | 02:39 | So let's go ahead, save that in
our buffer, and let's do that.
| | 02:43 | So let's Shift+Select our ground, so
it unselects it,. We're going to go to
| | 02:48 | Window > General Editors >
Attribute Spread Sheet.
| | 02:52 | In the Render tab, we're going to select
Primary Visibility, and we're going to type off.
| | 02:57 | Now all the objects that are selected, their
prime visibility is going to be turned off.
| | 03:03 | Next let's go into View > Image
Plane, and let's select our Image Plane.
| | 03:10 | We're going to turn the Di,splay mode to None.
Let's render out our scene and see what we get.
| | 03:16 | We're almost there. We're noticing that
there are some issues with the quality of
| | 03:21 | our render, so we're going to have to
address those now too. Let's save that in
| | 03:25 | the render buffer. Let's open up the Hypershade
one more time, so we have access to the shader.
| | 03:30 | Let's double-click the material, and
let's set the Samples to something like 32;
| | 03:35 | increase the quality.
| | 03:37 | And one last thing is, we notice that
the spread where the occlusion shader is
| | 03:42 | rendering too far out from the object.
We want to bring that in nice and tight,
| | 03:47 | so let's bring the spread maybe to half;
something like about .4, and let's render that out.
| | 03:55 | And now let's compare our two renders here.
| | 03:56 | So the quality got better, and the
spread got brought in a little bit.
| | 04:02 | Now that we have our ground occlusion pass,
we need to create a ground shadow pass.
| | Collapse this transcript |
| Creating a ground shadow pass| 00:00 | So, as I mentioned earlier, I like to mix
the ground occlusion with the ground shadow.
| | 00:06 | Let's use our latest lighting
file to spawn from in order to create
| | 00:10 | the groundShadow file.
| | 00:12 | The reason is because we already have
our key light in there, and we don't have
| | 00:16 | to re-create a key light
just for this file.
| | 00:18 | So here we are in the groundShadow file
I made from my latest lighting file, and
| | 00:23 | the first thing we want to do is we want to
select the key light, and let's make sure
| | 00:30 | the color of the key light is set to
white, because the end result is we just
| | 00:34 | want a black and white image.
We don't want much color in this.
| | 00:37 | So let's select the color swatch, and
let's just set to white, and now let's open
| | 00:43 | up our Outliner. Window > Outliner, and we
are going to select just the elements we
| | 00:50 | want in our new render layer,
which we are going to call groundShad.
| | 00:55 | So, the key light, the ground
plane, the shotCam, and the car.
| | 01:01 | So let's go over here and select the
icon, which is going to create a new
| | 01:04 | render layer with just the selected objects.
Double-click; I am going to call this groundShad.
| | 01:11 | Next we are going to want to assign
a white Lambert Shader to the ground.
| | 01:18 | Window > Rendering Editors > Hypershade, and
let's create a Lambert Shader; a new one.
| | 01:26 | Double-click, let's select the color to
white, select our ground plane, and let's
| | 01:32 | assign that material to the
ground plane. Minimize that.
| | 01:37 | In our ground shadow renderer, we do not
want the car's primary visibility on, just
| | 01:42 | like we did in the ground
ambient occlusion.
| | 01:45 | Let's select the car Window > General
Editors > Attribute Spread Sheet. In the Render
| | 01:52 | tab, Primary Visibility let's
turn it off. Let's close that.
| | 01:58 | Finally, what we are going to want to do
is create a unique shadow render pass.
| | 02:04 | We go here to Render Settings, and
now we select Create new render pass.
| | 02:09 | It's going to give us our list. Since
they are alphabetized we just scroll down;
| | 02:15 | here is Shadow. Create and Close.
| | 02:18 | Now we need to drop that shadow
down into the Associated Passes.
| | 02:22 | Notice I'm doing this while on
the ground shadow render layer.
| | 02:27 | That means that this shadow pass is only
going to be associated to this render layer.
| | 02:32 | Double-click the shadow pass, and now we
can set the Frame Buffer Type to what we
| | 02:38 | like; maybe 32-bit Float.
| | 02:40 | Let's go ahead and render
out, and see what we get.
| | 02:46 | To make our compositing easier, we do not
want to render on black, so we are going
| | 02:51 | to set the camera background to
white. Under View > Camera Attribute
| | 02:54 | Editor > Background Color, white.
| | 02:59 | Let's put this render in our
buffer. Let's do another render.
| | 03:04 | So now we should be ready to batch render.
| | 03:08 | Once we have batch rendered -- let's go
to Nuke, I have a pre-rendered one right
| | 03:11 | here; our ground shadow, notice
it's on a white background now.
| | 03:14 | This will make it a lot easier when we
mix it with our ground ambient occlusion
| | 03:19 | to our back plate in Nuke.
| | Collapse this transcript |
| Adding ambient occlusion| 00:00 | Ambient occlusion is a black and white
render pass that is an approximation of
| | 00:05 | global illumination that darkens pieces
of geometry that are in close proximity
| | 00:10 | to one another, and that will add a more
realistic effect to our final image.
| | 00:15 | So here I have a pre-rendered image of
our ambient occlusion render pass, and as
| | 00:21 | you can see, on the side here where the
surface geometry is not close to another
| | 00:26 | piece of geometry, it's all white.
| | 00:29 | As the geometry gets closer to other
pieces of geometry, we get a darkening
| | 00:34 | effect, and we're going to want to
bring that into our composite, and
| | 00:38 | multiply that, which is just going to give us
a more realistic render for our final output.
| | 00:43 | So, there are a couple of different ways
in which to create this ambient occlusion
| | 00:47 | pass, and let's go into Maya, and I'm
going to show you those different ways here.
| | 00:52 | The first way is in our Render Passes,
we have the AO, which is short for ambient
| | 00:59 | occlusion, and we can bring that
down into our Associated Passes,
| | 01:05 | and we can double-click that
to bring up its parameters.
| | 01:08 | And we now can set the Frame Buffer
Type to either 8-bit, 16-bit, or 32-bit.
| | 01:15 | Now, since we are using the ambient
occlusion as just a black and white pass,
| | 01:20 | it's really not necessary to render
it out at 32-bit; it just adds a little
| | 01:24 | more render time in the final stages of the
render when it's rendering all the render passes,
| | 01:28 | so let's just keep it to 16-bit for now.
| | 01:32 | If we scroll down here, we have a set
of parameters that we can now dial in
| | 01:37 | specifically for that render pass.
| | 01:40 | When we render this out we will get,
along with the indirect, reflection,
| | 01:46 | refraction, and shadow, and the other
passes, we will also get the AO pass into
| | 01:51 | our final EXR file.
| | 01:54 | There is a second way in which we can
create an ambient occlusion pass, which
| | 01:58 | gives us a little more control over
our render settings, and that is if we
| | 02:05 | create a custom ambient occlusion shader, and
assign it to the car on its own render layer.
| | 02:10 | So let's go ahead and bring that AO
pass out of our Associated Passes. Let's
| | 02:14 | close our Render Settings.
| | 02:16 | Let's go ahead and create that new render
layer. I'm going to just select the lights;
| | 02:21 | we're not going to use those. I'm
going to do a Ctrl+H and hide that.
| | 02:25 | Let's select this entire car, and with that
selected, I'm going to create a new render layer.
| | 02:30 | And I'm going to double-click that
render layer, and we're going to call this
| | 02:33 | something like carAO.
| | 02:36 | I am going to go ahead and open up
my Hypershade. I have got a quick key
| | 02:40 | which is H; opens up the Hypershade
without going up to our Window > Rendering
| | 02:46 | Editors > Hypershade.
| | 02:47 | And I'm going to create a new Surface Shader.
| | 02:51 | Let's back out of here, and
create a little more room here.
| | 02:55 | And now I'm going to select mental ray,
and I am going to shorten up this list a
| | 03:00 | bit, so we don't have to go
looking for our ambient occlusion shader.
| | 03:04 | So I'm just going to type in amb,
and now I'm going to select the
| | 03:08 | mib_amb_occlusion shader.
| | 03:12 | With it selected, I'm going to middle
mouse drag on top of the surfaceShader. I'm
| | 03:16 | going to select Default, which is going
to automatically attach it to the Out
| | 03:22 | Color of this surfaceShader.
| | 03:23 | I'm going to follow along where that
attached here by selecting the little arrow
| | 03:28 | key, and now that will give us our
parameters, which is basically the same thing
| | 03:32 | as double-clicking the mib_occlusion here.
| | 03:35 | Our final step here is we want to
assign that shader to the geometry, so let's
| | 03:40 | select all the geometry.
| | 03:42 | And it's very important;
| | 03:42 | we're on our carAO render layer, and
right-click, Assign Material to selected.
| | 03:52 | Finally, let's go into our Render
Settings window and make sure Raytracing is
| | 03:58 | set to on, which it is.
| | 04:00 | And let's go ahead and hit our
Render button, and let's see what we get.
| | 04:06 | So, there's a couple of things that
we're going to have to adjust here.
| | 04:10 | The first is that we don't want to
render on a white background; we want to
| | 04:15 | render on a black background.
| | 04:17 | Let's scoot the Hypershade out of the
way, select View > Camera Attribute Editor,
| | 04:23 | and let's scroll down to our
Environment rollout, and let's set our Background
| | 04:28 | Color to black. Let's close that out.
| | 04:31 | And now we want to adjust the
quality of the ambient occlusion render.
| | 04:37 | Notice, right around areas of
darkening we're getting little speckles.
| | 04:43 | That's because our samples are set a little
bit too low, so we want to bring those up.
| | 04:48 | So let's double-click our shader, and
let's bring our Samples from the default of
| | 04:52 | 16 to, let's say, around 32.
Save that into our render buffer.
| | 04:57 | Let's go ahead and do another render.
| | 05:01 | Let's compare it with what we
had from our previous render.
| | 05:04 | The Samples really helped
improve the quality of the render.
| | 05:07 | We're not getting all of the little
speckles that we were getting before.
| | 05:12 | We can also make some
other minor adjustments here.
| | 05:14 | We can bring down the Spread, which
takes the dark areas, and spreads them out a
| | 05:19 | little bit wider.
So maybe let's reduce that.
| | 05:23 | Our Max Distance is another very
important parameter here, and that is
| | 05:28 | dependent upon our scene scale; how
big our geometry is in our scene, and how
| | 05:34 | the ambient occlusion affects
the geometry, based on that scale.
| | 05:39 | For our purposes, let's select that to 1,
and we're just going to have to do some
| | 05:44 | test renders. Let's put that in our
render buffer, and do another render.
| | 05:47 | It looks like our Max Distance might
be set a little bit too high. Let's
| | 05:51 | bring that back to 0.
| | 05:52 | Let's keep our Spread to 0.4.
| | 05:55 | Let's put that in a render buffer,
and let's do another final render.
| | 05:59 | We're looking pretty good here.
| | 06:00 | So, now you can see the differences in
quality that we're getting, and I think
| | 06:04 | that's about the darkening we want,
roughly, and we got rid of a lot of the
| | 06:08 | artifacts in our render.
| | 06:10 | I showed you a couple of different
ways in which we can create our ambient
| | 06:13 | occlusion pass; either this custom way,
which is manually creating the shader, and
| | 06:18 | assigning it, and making a new render layer.
| | 06:20 | The other one is adding the AO pass
down into our Render Passes, and we get that
| | 06:25 | one for free when we're
creating our lighting pass.
| | Collapse this transcript |
| Adding a fresnel pass| 00:00 | The next pass we are going to
want to explore is the fresnel pass.
| | 00:04 | Fresnel occurs when the object facing
most perpendicular to camera has less
| | 00:08 | reflection, giving the illusion that the
reflected areas are actually greater on
| | 00:13 | the edges, which is similar to car paint.
| | 00:16 | So, here is an example rendered out on
a shader ball, where if we look in the
| | 00:22 | center of the image, there is very
little reflection, but as we go out towards
| | 00:27 | the edges, there is quite a bit more
reflection, and we are going to want to
| | 00:32 | mimic that in our composite.
| | 00:34 | But in order to do so, we are going to
have to create a unique render pass with
| | 00:39 | a custom shader in order to render that
out, and then bring that into our composite.
| | 00:43 | So, let's go ahead and I am
going to show you how to do that.
| | 00:47 | We are here in our last file, and we are
going to just use fresnel pass in order
| | 00:52 | to create this separate render layer.
| | 00:54 | And again, you can use any pass you'd like;
| | 00:57 | you can start with a lighting pass,
| | 00:59 | just as long as you make sure that
we have the correct file that's being
| | 01:03 | referenced into the shading file.
| | 01:05 | So with the carAO selected, let's change
that render layer name to fresnel, and I
| | 01:11 | am going to hit the H key
to bring up our Hypershade.
| | 01:15 | We are going to now create a
couple of new shaders in here.
| | 01:19 | First one is our Surface Shader, so
let's scoot out here a little bit to create
| | 01:24 | some more working room.
| | 01:26 | The next is we're going to select Utilities.
| | 01:28 | Within the Utilities, we are going to
create what is called a Sampler Info node.
| | 01:35 | So we can scroll down, and try and locate
that here, or again, just type in s, a, m,
| | 01:42 | and it just shortens up the list a little
bit, and makes it easier to find. Just
| | 01:46 | bring the Sampler Info node in here.
| | 01:49 | And the final shader we are going to
want to bring in here, actually, it is going
| | 01:53 | to be a 2D Texture, and it is a Ramp.
| | 01:57 | So the Sampler Info node, let's open
that up here, and the Sampler Info node
| | 02:02 | takes its information from the facing
angle of the camera, using the Facing Ratio
| | 02:07 | parameter inside Utility.
| | 02:09 | We are simply going to add
color at that angle using a ramp.
| | 02:15 | We use a ramp to then
adjust the amount of the effect.
| | 02:18 | So the first thing we need to do is
let's select the ramp, and we're only going
| | 02:23 | to really need two colors: black, and white.
| | 02:26 | White will be the color of our luminance.
| | 02:30 | Since the Ramp Type defaults to v, we
are going to put the white at the bottom,
| | 02:35 | and the black at the top, and then we are
going to attach that ramp to the Facing
| | 02:41 | Ratio of the Utility.
| | 02:42 | We only need black and white.
| | 02:44 | Let's get rid of this middle color by
just clicking this little x here, and we
| | 02:48 | are going to set the top color to
black, and now we are going to select the
| | 02:54 | bottom color to white, and
let's just close that out for now.
| | 03:00 | Let's middle mouse button, drag our ramp
on to our samplerInfo node, and instead
| | 03:05 | of selecting Default, this
time we're going to select Other.
| | 03:08 | By selecting Other, that is going
to bring up our Connection Editor.
| | 03:14 | So, let's go ahead and flop this
from, and to, so our Output is going to be
| | 03:19 | facingRatio, and we are going to connect
that to the v coordinate of the ramp.
| | 03:25 | And the reason why we are going to
connect that to the v coordinate of
| | 03:29 | the ramp is because our Ramp Type is
set to v. We're now going to middle mouse
| | 03:33 | and drag onto our surfaceShader, and we're
going to select Default which simply puts
| | 03:40 | our connection into the Out
Color of our surfaceShader.
| | 03:44 | Now we can select all the geometry on
the car -- let's close out our Connection
| | 03:49 | Editor, and let's select our car, and
we are going to right mouse click, and
| | 03:56 | Assign Material To Selection, and let's
go ahead and render out of our first
| | 04:02 | render, and see what we get.
| | 04:04 | We got a render that's starting to
work, but the effect of the fresnel is much
| | 04:09 | too widespread over the entire car.
Let's put that in our render buffer.
| | 04:13 | The way in which we can now
dial this in is through the ramp.
| | 04:18 | Notice that my black color is
all the way at the top the ramp.
| | 04:23 | What we can do is just simply select
the black color, and just drag it down
| | 04:27 | somewhere here, and that will create
more black color where the white color is.
| | 04:34 | So let's do another render.
| | 04:37 | That looks a lot better. Let's put
that into our render buffer as well.
| | 04:42 | Typically, the number I like to use to
get a proper fresnel is the Selected
| | 04:47 | Position of the black color is around 0.4.
| | 04:49 | It's probably not going to be that
much of a difference between our previous
| | 04:53 | render, but let's go
ahead and re-render it again.
| | 04:56 | We can compare our previous render with our
last render. So, it's a little bit different.
| | 05:00 | As you can see just by looking at the
render, we're getting a lot more of the
| | 05:06 | edge brightness that mimics our
fresnel shader that we saw before.
| | 05:11 | We are going to take this pass, now,
we are going to bring it into Nuke, and
| | 05:15 | there is a couple of different ways in
which we could use it into Nuke to mimic
| | 05:19 | that fresnel look.
| | Collapse this transcript |
|
|
6. Compositing the Rendered Passes in NukeAdding a gamma correction in Nuke| 00:00 | The rendered image in Nuke looks bright
and washed out, if you've noticed, when
| | 00:03 | I've opened up Nuke, and
brought in our car EXR file.
| | 00:06 | That's because linear images from programs
like Maya, and other 3D packages, do
| | 00:11 | not take into account the gamma
curve attributed to the monitor.
| | 00:15 | And we can take a look here at what that
monitor gamma curve actually looks like.
| | 00:20 | So, if we go back into Maya here real
quick, and I've rendered out what our latest
| | 00:25 | car render looks like, with all its lighting,
and its HDRI, it actually looks good.
| | 00:30 | That's what I like, because when I'm
working, I want what my final output is to
| | 00:33 | look like here in Maya.
| | 00:35 | So, Maya actually applies an sRGB gamma
correction under the hood for this render
| | 00:41 | view, so it's going to be
in the right color space.
| | 00:44 | Unfortunately, Nuke does not
apply that same gamma correction.
| | 00:47 | Let's go back to Nuke here.
| | 00:51 | So, we can see that it's
still washed out, and bright.
| | 00:53 | Well, we can make some adjustments in
Maya, so the image will have an sRGB gamma
| | 00:57 | correction, but that requires changing
all the textures and the colors to Linear,
| | 01:03 | and that's quite a bit of work.
| | 01:05 | So another way to avoid all this work
is to simply make the change in Nuke.
| | 01:09 | We can do that by adding a Grade
node, so let's zoom in here a little bit,
| | 01:14 | let's delete that, I'm going to go to
Tab, and we're going to hit Grade, and
| | 01:19 | another way to do that is just hit the G key,
and we're going to set our gamma to .454.
| | 01:27 | And the reason we set it to .454 is
because the sRGB gamma correction is 2.2.
| | 01:33 | The inverse of 2.2 is .454.
| | 01:35 | When we invert 2.2 with .454,
we end up with a linear image.
| | 01:44 | So now we look at our Grade node, and
now we can compare that to our Maya file,
| | 01:50 | and now they're in the same color space.
| | 01:53 | When rendering your own projects, make
sure you either apply the gamma correction
| | 01:56 | in Maya, or how we're doing it
here in Nuke, using the Grade node.
| | Collapse this transcript |
| Getting started in Nuke| 00:00 | So, now that we have all our rendered
elements, we can now set up our Nuke composite.
| | 00:06 | The first thing we need to do is read
in our car.exr file, which I demonstrated
| | 00:11 | how to create at the end of chapter 4.
| | 00:14 | We can either click-drag it in, like this, and
then view it. So, let's go ahead and delete that.
| | 00:21 | The other thing is, we can hit the R
button, which creates a Read node, and then it
| | 00:27 | automatically browses for
the location of the file.
| | 00:31 | So, here we are in our car/images
directory, in our Car.exr.
| | 00:36 | So let's go ahead and open that up, and
let's go ahead and add that Grade node
| | 00:40 | that we have been working
with in our linear workflow.
| | 00:43 | Let's hit the shortcut G, and let's
hit the gamma to .454, so now we have a
| | 00:50 | properly gammaed image.
| | 00:52 | I also like to set my Properties to
less than 10, preferably 1, so I only have
| | 00:58 | one Property node in Nuke at a time.
| | 01:01 | The next thing we want to do is we want to
set our Project Settings; the shortcut
| | 01:06 | key for that is S, and within our Project
Settings, we want to set our full size format.
| | 01:12 | As you can see, everything we have rendered
out from Maya so far was set to 1280 by 720.
| | 01:18 | Nuke defaults something other than that.
| | 01:21 | This simply means that if we bring in
any script generated elements, such as
| | 01:25 | constants, and color bars, and roto
shapes, it'll automatically default to
| | 01:30 | the full size format.
| | 01:32 | So for instance, let's hit the Tab bar.
| | 01:34 | I am going to type in a
constant, and let's view that.
| | 01:38 | So now we are at 2048 by 1556.
| | 01:43 | We want to have all these script-generated
elements to be the same as
| | 01:46 | our rendered elements.
| | 01:48 | So let's hit S again, and
let's select 1280 by 720.
| | 01:54 | We can also create new ones.
| | 01:56 | So for instance, we can type in Car HD, and
then we can type in 1280 by 720, and let's say OK.
| | 02:07 | Notice right away that are Constant
now sets its default size to 1280 by 720.
| | 02:13 | Back in our Project Settings,
we also have our proxy scale.
| | 02:17 | Our proxy scale enables us to work at
a much smaller resolution, making our
| | 02:21 | workflow much faster, so we don't have
to render everything out at 1280 by 720
| | 02:26 | while we are in the Nuke comp.
| | 02:28 | So, right now we are set at .5,
which is 50% our HD scale.
| | 02:32 | So, to enable proxy scale, we can go up to
our Viewer here, and toggle proxy scale on.
| | 02:38 | Let's view our Grade node.
| | 02:40 | So we are at half-res now: 640 by 360.
| | 02:44 | Our hot key in order to initiate our
proxy scale in Nuke is Ctrl+P on a PC,
| | 02:50 | and Command+P on a Mac.
| | 02:52 | Also, in our Project Settings, notice that
there is frames per second, and frame range.
| | 02:59 | We can ignore that for now,
because we're only rendering a still.
| | 03:02 | These are very important attributes
to set if you are working in animation.
| | 03:06 | Now we are ready to composite.
| | 03:09 | Our Car.exr has embedded render passes
that we created out of mental ray.
| | 03:14 | We're going to have to extract all
those passes using shuffle nodes, and then
| | 03:18 | putting them together into a single image.
| | 03:21 | So then, once they are separated out,
we can use our mattes that we created to
| | 03:25 | color correct each of those render passes.
| | 03:29 | So, let's hit the Tab key,
and create a new Shuffle node.
| | 03:34 | Let's bring the leader up to Grade, and
under our rgba, let's select diffuse.
| | 03:41 | Let's rename our Shuffle node to diffuse,
because we are going to be creating a
| | 03:46 | couple of these here now.
| | 03:48 | Tab, Shuffle, into the Grade node, and now
let's redirect that to indirect, and rename it.
| | 04:00 | So now we can view the
diffuse in indirect passes.
| | 04:04 | There we go. That looks pretty good.
| | 04:06 | So let's keep going here.
| | 04:07 | We have several more to do. Shuffle, into
the Grade node, next is reflection, and
| | 04:16 | let's just call this reflection. Tab,
Shuffle, let's bring the leader up to
| | 04:22 | Grade, into the refraction, call this
refraction, and take a look at that too;
| | 04:30 | make sure we got it right.
| | 04:31 | Bring the leader to the Grade, and
under our rgba, let's select specular, and
| | 04:41 | let's just call this
specular. Let's take a look that.
| | 04:45 | So now what we're going to probably
have to do is we are going to have to use
| | 04:52 | the Merge node with the operation
set to plus, and add them all up.
| | 04:55 | So the hot key for the Merge node is M,
or Tab, Merge, bring the leaders here,
| | 05:05 | double-click, make sure it's in our
property window, set the operation to plus.
| | 05:11 | Now that would be the
diffuse and the indirect added.
| | 05:13 | Let's go ahead and
create another Merge node.
| | 05:17 | We are going to keep adding all these
passes up here. Set the operation to plus.
| | 05:24 | We've got specular. Let's go ahead and
create another Merge node. Make sure it's
| | 05:31 | in our property window.
Set the operation to plus.
| | 05:36 | With the node selected, on the keyboard
hit Ctrl+C, and in the empty space here
| | 05:40 | Ctrl+V. We are going to keep adding all
these passes up here; it saves me a bit
| | 05:45 | of time. And now finally, we
have to add a new Grade node.
| | 05:49 | So let's just Ctrl+C;
copy and paste that here.
| | 05:54 | So now all our associated passes add up
to what our original render looks like here.
| | 06:00 | Now that we have our basic setup
in Nuke, we can start to color correct
| | 06:03 | our passes.
| | Collapse this transcript |
| Color correcting the passes using mattes| 00:00 | Now that we've all our passes added
together, we can begin to make adjustments to
| | 00:04 | individual render passes.
| | 00:06 | As mentioned earlier, this is where the
real benefit of rendering in 32-bit lies.
| | 00:11 | Here we are again in our Nuke file,
with all our passes separated out.
| | 00:17 | We're viewing our Grade node.
| | 00:20 | First thing we want to do is we want
to bring in our rendered matte passes.
| | 00:23 | Let's go ahead and open up a Windows
Explorer window, browse to our images
| | 00:27 | directory, and Shift+Select our mattes,
and click-drag them into our Nuke file.
| | 00:33 | Let's minimize the Explorer window.
| | 00:37 | And just by looking at our image, we
can make some initial decisions about
| | 00:42 | what we want to change.
| | 00:43 | Looks like the tires might be a
little bit dull; we want to bring those up.
| | 00:47 | Also, we want more specular highlight,
possibly just in the body paint. So let's
| | 00:51 | separate out our mattes, so we can easily
see them; get a little more organized.
| | 00:57 | And since we want to bring up the tires, the
diffuse channel is a really good place to do that.
| | 01:02 | So let's bring our M2 node over here,
and we're going to have it selected, hit
| | 01:07 | Tab, type in Shuffle.
| | 01:11 | If we just view just the M2 node, the
tires are isolated on the red channel.
| | 01:17 | So in the Shuffle node, let's do the same
thing: R, G, B, and A for red, so now we
| | 01:23 | have a matte just for the tires.
| | 01:25 | Zooming out a little bit, select that
Shuffle node just for the diffuse pass.
| | 01:30 | And now we're going to hit Tab, and let's
put in an Exposure node, and take a look
| | 01:35 | at that too; make sure we have it right.
| | 01:39 | And probably a good idea is here we're
going to view the Grade node, so we can
| | 01:44 | see our end result.
| | 01:45 | So now we can see
we're bring up those tires.
| | 01:50 | Next, let's go to our specular channel.
| | 01:54 | As I mentioned earlier, it looks like
our specular channel could use a little bit
| | 01:58 | of attention, just on the paint. Go
ahead and find our paint matte, and let's
| | 02:04 | bring that over to where our specular
channel is. With it selected, Tab, Shuffle;
| | 02:12 | let's view the node. So, we want to
isolate out just the red channel.
| | 02:16 | So we're going to select red for R, G,
B, and A, so now we have just our paint.
| | 02:23 | And with our specular shuffle node
selected, Tab, ColorCorrect; let's bring that
| | 02:30 | down over here. Let's take the mask leader,
bring that into the Shuffle node. We can view that.
| | 02:38 | Now we can bring up our contrast,
bring up our gamma, and bring up our gain.
| | 02:44 | So now let's take a look here at our
Grade node, and kind of compare the two: our
| | 02:52 | first Grade node here, and
our second Grade node here.
| | 02:55 | So those are just two very simple color
corrects. One of them is just an exposure.
| | 03:01 | I can continue showing you more
adjustments, but I'm going to just quickly
| | 03:05 | show you my end results.
| | 03:07 | So, I actually have, here in the same comp,
my adjustments to all of my render passes.
| | 03:14 | So here you can see the adjustment for
the tires. Here's the adjustment for the
| | 03:20 | specular pass I showed. I also added a glow.
| | 03:25 | Here is my adjustments for reflection.
| | 03:29 | I actually added a merge node, with the
operation set to plus, and I added more
| | 03:34 | reflection, so we can look
at the Grade node.
| | 03:37 | And then finally, my refraction pass; I
increased my refraction ever so slightly.
| | 03:43 | So now let's select this Grade node at
the bottom, the Grade node at the top, and
| | 03:48 | we can compare the two.
| | 03:51 | So as you can see, this is where
the real artistry takes place.
| | 03:55 | These methods can be applied to any
new composites where you need to make
| | 03:58 | adjustments to your render passes.
| | Collapse this transcript |
| Adding the secondary passes| 00:00 | Next we need to bring ambient
occlusion into our new comp.
| | 00:04 | As you recall, we rendered an AO pass
from the associated pass section in Maya.
| | 00:10 | And here in our comp, I created a shuffle
node, and I shuffled out the AO pass, so
| | 00:18 | let's take a look at what
that AO pass looks like.
| | 00:21 | So now what we need to do is we have to
multiply that into our composite, so I
| | 00:28 | went ahead and I created a merge node,
and I set the operation to multiply.
| | 00:33 | Let's go to the end of our comp, and
let's take a look at our Grade node. I'm
| | 00:37 | going to put that on the
number 2 for our viewer.
| | 00:40 | And now let's unhook our multiply, so
we can kind of see the difference of our
| | 00:46 | Grade node image, with and without our
ambient occlusion. So I'm going to select
| | 00:50 | this leader. I'm going to just put
it over here into our plus node.
| | 00:53 | So now our ambient occlusion is
not being rendered in our new comp.
| | 00:57 | So, notice that the car actually became
a little bit lighter. Put that leader
| | 01:02 | back into multiply, and notice that
where our geometry is in close proximity to
| | 01:08 | other pieces of geometry, we get
darkening. So, we want to include that ambient
| | 01:12 | occlusion pass in our final new
composite, because it just adds one more level
| | 01:18 | of realism to our image.
| | 01:20 | Another level of realism is our
fresnel pass. We need to add that into our
| | 01:26 | reflection pass that we rendered out from Maya.
| | 01:30 | So let's go ahead and create a read node.
I'm just going to select here in open
| | 01:35 | space, hit the R key; we're going to
go into images, and we're going to go to
| | 01:41 | fresnel, select our fresnel.exr, and
open that up. Take a look at that.
| | 01:46 | So this is our secondary pass of just fresnel.
| | 01:50 | As you recall, we only want just the
outside edges of the paint to be affected.
| | 01:58 | So, in order to do that, we have to have a
Bezier. I actually created a Bezier; now
| | 02:03 | I'm going to just copy and paste that.
We're going to take a look at that.
| | 02:07 | So, if you notice, if I select on the
Color tab, set to Black, so the inside
| | 02:12 | of that Bezier is black, so we're
only having the outside edges of our
| | 02:17 | fresnel being affected.
| | 02:19 | Next, we want to have the fresnel, not
only just the outside edges, but also
| | 02:23 | just the car paint.
| | 02:25 | Let's go ahead and take an existing M1
matte, which is our car paint matte, and
| | 02:29 | we're just going to use that. I'm
going to hit Ctrl+C on our keyboard just to
| | 02:33 | copy, and I'm going to now
hit Ctrl+V, Tab, Shuffle.
| | 02:40 | And we're going to set this Shuffle to R,
so now we're just isolating our car paint.
| | 02:48 | Let's select the Shuffle, and Shift+Select
our Bezier. Hit M for merge, and let's
| | 02:55 | select our Merge operation to mask.
| | 03:00 | So if we take a look now, the mask only
affects the body paint with the outside
| | 03:08 | selected from the Bezier.
| | 03:10 | Finally, we want to incorporate
that into our reflection pass.
| | 03:15 | Here is an exposure node; let's
create another one. Tab > Exposure.
| | 03:23 | And we're going to want to take the
mask leader of our exposure, and into
| | 03:27 | our mask of our merge.
| | 03:31 | And we have our new exposure node viewed.
| | 03:34 | Let's bring up the red, green, and blue,
which basically just brings up the
| | 03:39 | overall level of the effect
onto the reflection pass.
| | 03:45 | So, as you recall, when we're creating
the fresnel pass, just the outside edges
| | 03:50 | are going to have more reflection.
That's why we included it in just the reflection
| | 03:53 | pass, and that's what we're getting here.
| | 03:55 | So if we view a before and after of
just a reflection pass, you can see the
| | 04:00 | fresnel being affected here.
| | 04:01 | So there is a pretty good way of adding
that fresnel pass just onto our reflection.
| | 04:05 | So our next step, we need to add
our background image to our comp.
| | Collapse this transcript |
| Adding the background plate and the shadow| 00:00 | So now that we have added all our color
corrects to our render passes, now is a
| | 00:05 | good time to add in our background
image, and if we add our background image,
| | 00:10 | we're going to have to add in our ground
shadow, and our ground ambient occlusion pass.
| | 00:17 | I think the best way to start is to
open up our previous Nuke file, where we
| | 00:22 | color corrected our background plate.
| | 00:25 | So, here's our background plate pre-comp,
where we color corrected the background plate.
| | 00:29 | Notice that the image size here
is 5184 to 3456.
| | 00:34 | So we're going to have to
reformat that into our Master comp.
| | 00:40 | Instead of just taking out the Write
node that we used, why don't we just go
| | 00:45 | ,
ahead and take the color corrects,
and just put that in our Master comp.
| | 00:50 | With those nodes selected, I'm going to
do a Ctrl+C. Now let's go back into our
| | 00:56 | Master comp, and let's put those in here,
and we're going to do a Ctrl+V to paste.
| | 01:02 | Next, we are going to want to
bring in our groundShadow pass.
| | 01:07 | So let's hit the R key for Read, and
we're going to go down to our images
| | 01:13 | directory, and groundShadow,
and we're going to open up our
| | 01:17 | groundShadow.exr. Let's view that.
| | 01:21 | Notice that when we rendered out our
ground shadow, we have a darkened area of
| | 01:26 | our shadow, and then it's
on a white background.
| | 01:29 | What we need to do is isolate just the
dark area, and we can then multiply back
| | 01:35 | onto our color corrected plate.
| | 01:38 | So, the first thing we want to do in
order to isolate that is create a Bezier.
| | 01:41 | So, with the node selected, I'm going to
hit X, and we're going to type in Bezier,
| | 01:46 | and we're going to make
sure the TCL is selected.
| | 01:50 | With our Bezier selected, let's zoom
in here a little bit closer, and holding
| | 01:53 | down the Ctrl and Alt key, we're going
to start creating a Bezier, just around
| | 01:59 | the shadow darkened area.
| | 02:02 | So we're going to set some points on
the Bezier, and maybe one more point here.
| | 02:08 | Let's go ahead on the
Bezier, and let's invert that,
| | 02:12 | so we're looking at just the dark area.
| | 02:16 | Next we are going to want
to invert that selection.
| | 02:21 | Hit Tab, and we're going to type
in invert to get the Invert node.
| | 02:26 | Let's put a ColorCorrect node on there.
| | 02:29 | So hitting the C key, and let's bring
down our gamma; tighten it up a bit.
| | 02:34 | Notice that we're getting some
harsh edges around our shadow area.
| | 02:39 | So let's go back to our Bezier, and now
we can create some more feathered edges.
| | 02:44 | So with our Bezier points showing,
we're going to hold down our Ctrl key, and
| | 02:49 | left-click on each of the individual
points, and we're going to go around the
| | 02:54 | shadow, and just soften up those edges.
| | 02:59 | We can further tighten it up once we
have it multiplied onto our background.
| | 03:03 | Okay, so back to our background plate;
remember, it was 5K, so we're going to
| | 03:10 | have to put a reformat node on here.
Tab, Reformat, and now our reformat is to
| | 03:17 | 1280 by 720; the size of our composite.
| | 03:21 | With our ColorCorrect node
selected, let's view that.
| | 03:24 | It's really important that what we
see in our RGB is also going to be what
| | 03:30 | we see in our alpha.
| | 03:31 | So if I select our alpha channel, we're
going to notice that the entire shadow
| | 03:37 | is not selected;
just the edges of our Bezier.
| | 03:40 | So in order to get the rest of the
shadow in our alpha, we're going to have to
| | 03:45 | add a shuffle node on here,
so Tab, Shuffle.
| | 03:48 | Let's set the alpha red, and that will
now bring our alpha into our color channel.
| | 03:57 | So if we go back to our RGB, both our
RGB, and our alpha now carry the white,
| | 04:04 | which is what we want to use for our mask.
| | 04:07 | With our Shuffle selected, our Reformat
selected, let's hit M to bring in a Merge node.
| | 04:16 | And instead of having A over B, what we're
going to use, we're going to use that as a mask.
| | 04:22 | Let's bring our mask
leader up to our Shuffle node.
| | 04:25 | Now instead of an over, we're
going to set our operation to multiply.
| | 04:31 | Now we're seeing our shadow on the ground.
| | 04:34 | So, as you can see, our
Bezier is a little bit wide.
| | 04:37 | So we can go in and make some adjustments
by bringing down the main points of
| | 04:42 | the Bezier to the edge of the road in
the back, because we don't want to have
| | 04:46 | the shadow going up on
the rocks in the background.
| | 04:49 | So we are just going to bring
this down here a little bit.
| | 04:53 | Next, let's read in our ground occlusion,
selecting in our open space, hitting the R key,
| | 05:00 | I'm just going to go back up to the
images, and now we're going to go to the
| | 05:04 | groundAOC, and bring in the
groundAOC.exr; Open.
| | 05:09 | Now, this is just going to be a
simple merge with a multiply.
| | 05:13 | So we can either create a new one, or we can
just copy paste what we already have here.
| | 05:17 | So let's just do that. I am going to Ctrl+C,
and Ctrl+V. Let's bring that down over here.
| | 05:23 | We're going to view that, and we
have our multiply onto our ground.
| | 05:27 | We can adjust the amount of ground
occlusion by simply dialing down our mix.
| | 05:33 | Another little layer of detail we can do
too is we can actually adjust the color
| | 05:39 | of the ground shadow.
| | 05:41 | Let's move our color corrected
background images over a little bit here.
| | 05:45 | Let's select Tab,
and let's add a constant.
| | 05:49 | Now we're going to hook our
A leader up to our constant.
| | 05:53 | Now we can change this constant to any
color we want; that would be our shadow color.
| | 05:58 | So it doesn't necessarily have to be black.
| | 06:00 | We can have a little bit
of color into this shadow.
| | 06:03 | We can zoom into the window here a
little bit, and we can select the color
| | 06:08 | picker, and now, holding down the Ctrl
key and left mouse button, I'm able to go
| | 06:15 | in, and actually pick a very specific color
for the shadow, and then we can even go
| | 06:21 | in here now, and make it a
little bit darker if we wanted to.
| | 06:26 | So that's how we integrate the
groundShadow and groundAOC into the back plate.
| | 06:31 | Next, let's see how we
need to finish our composite.
| | Collapse this transcript |
| Adding the car and rendering the final composite| 00:00 | Now we need to apply our color
corrected car onto our background.
| | 00:04 | So, there's a number of ways
we can do this.
| | 00:06 | We can either create a new merge node
right here in our open space, and then
| | 00:10 | select the A and B leader, or even
simpler, we Shift+select our Grade node, and
| | 00:16 | Shift+select multiply, and hit M. Now
the over, which is our default for our
| | 00:24 | Merge node, will automatically
set our A over B.
| | 00:29 | Notice, though, that if we zoom in here
towards the windows, that we are not
| | 00:34 | getting any transparency to see the
background plate through the windows.
| | 00:40 | The reason is, if we look at our alpha
channel, we have no transparency in our alpha.
| | 00:47 | We need to get that transparency
back before we do the over operation.
| | 00:52 | Let's zoom up to our Car.exr,
and view the Grade node.
| | 00:56 | We have transparency in our
alpha at the very top of our comp.
| | 01:00 | We even have transparency
in all of our passes.
| | 01:04 | What happens, though, is that when we add our
passes together, we lose that transparency.
| | 01:10 | So if we work our way down the comp, by
the time we get to our Grade node here,
| | 01:14 | we are going to have no transparency.
| | 01:16 | The best solution for this is to copy
and paste our Car.exr with our Grade;
| | 01:21 | Ctrl+C. Let's go here in
open space, and Ctrl+V for paste.
| | 01:29 | Select our Grade node here, and Tab, Copy,
and we need to hook our Grade node -- and
| | 01:35 | actually, we don't even need our Grade
node at this case; all we are looking for
| | 01:39 | is just the transparency, so we can
delete that Grade node if we want.
| | 01:43 | We need to hook our Car.exr into the copy.
| | 01:47 | So we are going to just take just the
alpha channel of our Car.exr file, and use
| | 01:53 | it into the Master comp now.
| | 01:56 | Before we do that, let's select the copy
channel, and Shift+X to reverse the order.
| | 02:03 | Now let's view our over. Let's
select the Viewer back to RGB.
| | 02:09 | Now we can see that we have transparency,
because we're seeing the background
| | 02:14 | plate through the windows.
| | 02:16 | Now that our comp is almost complete, we
need to write this, and render it to disk.
| | 02:21 | So with our over selected, let's
hit the W key to create a write node.
| | 02:28 | Now we need to browse to
where we want to render.
| | 02:30 | So let's hit this little file
folder, and let's set it to images.
| | 02:37 | Now, here in the path, we can
create a new render file name.
| | 02:43 | Let's call it something like ConceptCarComp.
Render it out as a TIF file,
| | 02:49 | so we just put a .tif.
| | 02:52 | The great thing about Nuke is once we
add a particular file type, Nuke is smart
| | 02:57 | enough to know what file type to set it to.
| | 03:00 | So let's set the compression to none,
and let's leave our channels to RGB,
| | 03:04 | because we simply don't need an alpha
channel for our paint work in Photoshop.
| | 03:10 | So with our Write node selected,
let's hit Render, and say OK.
| | 03:16 | So now it's rendering through our comp,
and now we have our final render in which
| | 03:22 | to work with in Photoshop.
| | Collapse this transcript |
|
|
7. Final Touch-Ups in PhotoshopAdding motion blur to the wheels| 00:00 | Using Photoshop, we open up our tiff file
that we just rendered from Nuke to make
| | 00:06 | our final adjustments, and the first
order of business is that we need to add
| | 00:11 | some motion blur to our wheels.
| | 00:13 | I can do this in Maya, but it will
increase render times, and is probably
| | 00:17 | not as art directable.
| | 00:19 | So, I really prefer to do this
in post, typically in Photoshop.
| | 00:23 | So now that we have our rendered
version in Photoshop, let's zoom in, and
| | 00:30 | concentrate on our back wheel first.
With our Elliptical Marquee tool selected,
| | 00:37 | let's eyeball the center of the wheel,
and holding the Alt key simultaneously and
| | 00:42 | our left mouse button, we're
going to create a new ellipse here.
| | 00:46 | And I'm just going to eyeball it here
for now, because we can always go in and
| | 00:51 | make some fine tune adjustments
to get it to be exactly lined up.
| | 00:55 | That looks pretty good.
| | 00:56 | Now I'm using my left arrow key, and
we're just going to nudge the selection
| | 01:01 | over, and it looks like we're going to
have to bring maybe the top here down, and
| | 01:06 | the sides over here.
| | 01:07 | Let's go ahead and select Transform
Selection, bring that selection over. That
| | 01:13 | looks pretty good, and we're just
going to bring this down just a hair. That
| | 01:17 | looks pretty good. And let's say Enter.
| | 01:19 | Let's go ahead and copy and
paste this into a new a new layer.
| | 01:22 | So I'm going to hit Ctrl+C, and Ctrl+V,
and in the new layer, let's rename it
| | 01:29 | motionBlurRear for our rear wheel.
| | 01:35 | Let's go ahead and also
hide our Background layer.
| | 01:39 | We are going to need to make this
circular. See, it's very oval in shape?
| | 01:44 | The reason is because I'm
going to be using a radial blur.
| | 01:47 | Radial blurs work much better with
round objects then oval objects. Select
| | 01:54 | Edit > Transform > Scale, and we're just
going to eyeball this into place here; it
| | 02:01 | doesn't have to be exact. We've got
a pretty good looking circle here.
| | 02:04 | With our motionBlurRear layer selected, we
Ctrl+left mouse click to load the selection.
| | 02:11 | Now under Filter > Blur > Radial Blur;
let's set the amount to around 20.
| | 02:20 | That looks pretty good. Let's turn on
our Background layer, and we're going to
| | 02:24 | need to rescale our motion blurred wheels
to match the original render. With our
| | 02:31 | selection set, Edit > Transform > Scale, and
all we do is just bring that back up to
| | 02:39 | match what's underneath.
| | 02:40 | We can actually set our Opacity
little bit lower to see how close we are.
| | 02:46 | Looks like I really nailed it here.
I'm going to left mouse click here in the
| | 02:50 | image, and hit Enter.
| | 02:52 | And now Ctrl+D deselects our selection.
| | 02:57 | And now let's zoom out; I am just
going to hold the Shift key and the Alt
| | 03:01 | key simultaneously.
| | 03:03 | And that's what our
rear motion blur looks like.
| | 03:05 | So what you need to do now is go
in and do the front wheel as well.
| | 03:10 | Also, feel free to experiment a little
bit, and notice that I only did just the
| | 03:15 | chrome part of the rim. It might be cool
looking if you also include the tire as well.
| | 03:21 | And now the next thing we need to do
is go in and make some paint fixes to
| | 03:26 | the road.
| | Collapse this transcript |
| Fixing the road| 00:00 | Next, we have to make
some paint fixes to the road.
| | 00:03 | Painting out the lane line will
eliminate any problems that the car is actually
| | 00:07 | driving on the wrong side of
the road, at least here in the US.
| | 00:10 | We can also tighten up the
ground shadow a bit as well.
| | 00:14 | Let's start by selecting our
Background layer.
| | 00:17 | Let's make a copy of that, and double-click
in the layer, and let's call it roadFix.
| | 00:26 | Now let's select our Polygonal Lasso
tool right here, and what we want to do is
| | 00:33 | make a very tight
selection around that lane line.
| | 00:36 | So zooming in on it here, let's start on
the outside of the image, and let's just
| | 00:42 | start creating a selection around it.
| | 00:45 | So we can just pan down the image, and
we are going to go outside the image, and
| | 00:51 | then back around again.
| | 00:52 | So now we are just going to backtrack here.
| | 00:55 | Now we are going to complete the
selection, and zoom out a little bit.
| | 01:02 | Now, under Edit > Fill, we are going
to make sure that our Use is set to
| | 01:09 | Content-Aware, and Content-Aware simply
takes pixels from outside the selection,
| | 01:15 | and includes them in the new selection.
| | 01:18 | So, we are going to say OK.
| | 01:21 | Now let's do a Ctrl+D to deselect, and
our lane line is gone, but as you can see,
| | 01:28 | there are still some remnants of it. We
have got to go in and make some painting
| | 01:32 | adjustments in order to clean that up.
| | 01:34 | Probably the best way to do that is we
are going to use our Clone Stamp tool.
| | 01:40 | We set our brush to Opacity of
about 100%, our Flow to around 25 or so,
| | 01:48 | and our Brush Size to 15.
| | 01:49 | Of course, feel free to
adjust any of those parameters.
| | 01:53 | I am going to use my Alt key just to
select next to the area I want to paint,
| | 01:59 | and I'm going to start filling in
the area that needs some adjustment.
| | 02:03 | I am just going to be very careful not
to paint onto the car, and also careful
| | 02:09 | not to paint any of our valuable
ground shadow pass, or ground occlusion pass.
| | 02:14 | Let's change our Opacity a little
bit, bring that down, and adjust the
| | 02:21 | ground shadow here, so it's just not
so stark of an edge. There we go; looks
| | 02:27 | pretty good. And zoom out.
| | 02:30 | I don't want to have two background
layers, so we need to merge the two together,
| | 02:35 | and create a new background layer.
| | 02:37 | So in the Layers palette, we're just
going to merge down, and now we have our
| | 02:41 | new Background layer.
| | 02:43 | So, let's continue adjusting
our image, and add a vignette.
| | Collapse this transcript |
| Adding a vignette| 00:00 | Once we have all our paint fixes, I think it
would be a nice final touch to add a vignette.
| | 00:05 | So back here in Photoshop, with our
Background selected, let's go ahead and
| | 00:10 | create a new layer.
| | 00:12 | So I'm going to say New Layer, and
let's call it Vignette, and let's slide that
| | 00:18 | all the way up to the top, because we
want the vignette to be over our motion
| | 00:21 | blurred wheels,
and our background changes.
| | 00:24 | We need to create a new elliptical
marquee, so with our Elliptical Marquee
| | 00:31 | tool, again, holding our Alt key, we're going to
emanate this from the center of the entire image.
| | 00:37 | I'm going to Alt+Drag out, maybe
something around here, and now we can adjust
| | 00:44 | the location of it; Select > Transform
Selection, and we're just going to bring
| | 00:49 | this down just a hair.
| | 00:50 | That looks pretty good, and I'm also --
right now I'm looking at the sides of the
| | 00:55 | image, so I'm having about the same
amount of space on both sides of the image;
| | 00:59 | same amount of spaces from the
top to the bottom as well.
| | 01:02 | That looks pretty good. We're going to
Enter, and now we're going to invert our
| | 01:06 | selection, because we only want to
darken up the outside edges of the ellipse.
| | 01:13 | So I'm going to hold down Ctrl+Shift, and
I am going to hit I, and that's going to
| | 01:18 | invert the selection.
| | 01:19 | Next I am going to use the Gradient tool,
and I want the Gradient tool, instead of
| | 01:25 | going from black to white, I want
the Gradient tool going from black to
| | 01:31 | transparent, so I am going to say OK.
| | 01:34 | I want to use a Radial Gradient, so with
the Radial Gradient selected, I'm going
| | 01:39 | to go back to the center of my image,
and I'm going to left mouse button click,
| | 01:43 | and I'm going to drag
beyond the corner of the image.
| | 01:46 | So now we've got a nice gradient
going from transparent to dark.
| | 01:50 | Next let's Ctrl+D, so we deselect our
selection, and now we add a nice blur onto it.
| | 01:57 | So Filter > Blur, and let's go to Gaussian
Blur, and go ahead and adjust the amount
| | 02:05 | of blur that you like. Let's try and
make it where we're not seeing the edges so
| | 02:09 | much; probably say 50 pixel
Radius blur. So we say OK.
| | 02:15 | Now that we have the vignette on its own
unique layer, you can go in, and you can
| | 02:21 | adjust the transparency, depending
upon how strong you want the effect.
| | 02:25 | So we can just leave that at a 100% for now.
| | 02:28 | So here we have our final
rendered, composited, and painted image.
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ConclusionComparing the final composite with the original plate| 00:00 | So here's our original image,
and our final paint fixed image.
| | 00:06 | The tools I showed you can be used
for many purposes other than vehicles,
| | 00:10 | but hopefully this gives you a good
start in helping you set up your files, and
| | 00:14 | dialing in all your parameters.
| | 00:16 | Some other resources I
have here are jeffpatton.net.
| | 00:22 | jeffpatton.net is a great resource to
show how a commercial artist shoots his
| | 00:27 | HDRIs, and stitches them using PTGui
Pro, as well as some other great tools.
| | 00:33 | If we go to LAmrUG, which is the Los
Angeles Mental Ray User Group, this is a
| | 00:40 | fantastic Web site to show how
other artists are using mental ray.
| | 00:44 | There is mymentalray.com, which is a
great place to get involved in the mental
| | 00:50 | ray community, and to also see images
other artists are creating using the same
| | 00:54 | tools that I showed you.
| | 00:56 | Finally, on the 2D side of
things for Nuke, there is Nukepedia.
| | 01:01 | Nukepedia is a great URL to go and
download plug-ins, and to also view tutorials.
| | 01:07 | Thanks for watching, and have fun lighting.
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