Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Creating a light cache solution

From: SketchUp Rendering Using V-Ray

Video: Creating a light cache solution

In this video, we're going to be working with our same interior scene to create another global lighting solution, this time using V-Ray's Light Cache system set as our primary engine. We're going to follow the same procedure as with our irradiance mapping exercise. Let's see what kind of solution we can create using the basic Light Cache controls. So with our Ch03_GI scene file loaded, let's once again go and enable V-Ray's GI systems. To do that we need to open up the Options Editor, come down into Indirect Illumination rollout, and again put a check in the On box.

Creating a light cache solution

In this video, we're going to be working with our same interior scene to create another global lighting solution, this time using V-Ray's Light Cache system set as our primary engine. We're going to follow the same procedure as with our irradiance mapping exercise. Let's see what kind of solution we can create using the basic Light Cache controls. So with our Ch03_GI scene file loaded, let's once again go and enable V-Ray's GI systems. To do that we need to open up the Options Editor, come down into Indirect Illumination rollout, and again put a check in the On box.

Then of course, we need to go and setup our Engine Type, so let's scroll down. Let's set Light Cache as our Primary Engine and as before, we need to disable our Secondary Engine. And if we just scroll down, you can see that the system gives us some default settings so that we're literally ready to render with Light Cache. The problem with these default settings is that they really are assuming that we're using Light Cache as a secondary bounce engine, which really is its recommended role, and we'll mention that a couple of times throughout this video.

If we just dismiss our Options Editor though, we can take a test render for ourselves, and we should see a couple of things straightaway. Firstly, we notice that with those default settings, once the Light Cache calculation actually starts, it create a GI solution very, very quickly. We should also notice in the final render that we do get a lot of light bouncing around our environment. In fact, we're getting almost as much light here with Light Cache only as we did with both Light Cache and Irradiance Mapping in our previous exercise.

This is because Light Cache rays don't just bounce once; like photons from which this technology is derived, Light Cache rays, once they have been cast out into an environment-- that happens from the camera's point of view-- they will actually perform multiple bounces automatically, and they can do that very, very quickly. In fact, this is Light Cache's big strength. Unfortunately, you can see, as well as getting the speed and lots of light bouncing around our environment, we also get a very noisy end result in our render.

So clearly, we're going to need to revisit our Light Cache controls to see if we can improve the situation a little bit. Well, probably the first control we would think of working with is this Subdivs value, which again can be thought of as quality control for Light Cache. This really handles the number of rays, or samples, that the Light Cache system would use in its GI calculations. So let's see what would happen if we doubled our default value. Let's set a Subdivs value of 1600 in there and again, let's take a render.

Well, there is no doubt, looking at the final render, that we have most definitely improved our noise situation. But if you're following along with this particular exercise file, you'll have noticed that that render took considerably longer than our previous attempt. And of course, while we have improved things, we can see that we still have lots of blotchy noise present in the scene. You'll also notice that the transition areas between our direct and indirect illumination are also looking extremely rough. Naturally, at this point we would be tempted to go and increase our Subdivs value a little bit more, see if we can get a little bit of extra quality out of the scene.

But truth be told, even if we increase that Subdivs value up to something around about 5000 to 6000 in this scene, we would still encounter these particular problems, and of course our render times would increase by an even greater margin. Can we then, as with our Irradiance Map exercise, work with some of the other Light Cache controls in order to improve the solution? Well, let's go back into our Options Editor. One option that we may decide to work with, or may try to work with, would be these Filter Samples. Essentially more filter samples would mean a more blurry, and so less noisy, Light Cache solution.

As filtering doesn't really add an awful lot to render times, let's bump this up to something quite high, like a value of 30, and again just close down the Options Editor and test that out. Well, quite clearly, we have been able to smooth out our noise problems by quite a considerable amount; however, we now run into the problem that always occurs whenever we increase blurring or interpolation operations inside a GI system. You can see we really are starting to lose definition in our scene.

It is very difficult to pull out scene detail. We are getting lots of flat-looking areas simply because we're now creating such a large blurring operation inside the solution. Now we could counter this a little bit by going and enabling Ambient Occlusion inside of our Indirect Illumination controls. This is found just towards the top of our Indirect Illumination rollout. That would add a little bit of definition back into the system. But still, we would encounter the problems that we see. Coming from Light Cache, we would still see some of that loss of definition, and of course, our transitional areas between direct and indirect illumination are still looking very rough.

Again, we could try tweaking some of the controls available to us, so we could try and work with our Filter Type inside off the Light Cache rollout. We could try and work with our Filter Size a little bit to fine-tune the filtering. But ultimately, we would just have to acknowledge that Light Cache just does not work very well when set as the primary bounce engine, which of course is not at all surprising, as really this technology has been designed to function as an excellent secondary balance engine, which of course it is. In fact, you saw I've demonstrated in our Irradiance Mapping exercise.

So again, in this video we've spent a little bit of time showing you how we can quickly and easily create a Light Cache GI solution. We have demonstrated a couple of the quality control settings available to us, but ultimately we have discovered the Light Cache is just not very good when set as a primary bounce engine. Do remember though, all of the controls, everything that we've talked about here, are applicable to Light Cache when it is set as a secondary bounce engine also. Let's move on then to our next video where we'll take a look at the last of V-Ray's GI systems that we'll consider in this course.

This is the Deterministic Monte Carlo, or DMC, Engine.

Show transcript

This video is part of

Image for SketchUp Rendering Using V-Ray
SketchUp Rendering Using V-Ray

33 video lessons · 6206 viewers

Brian Bradley
Author

 
Expand all | Collapse all
  1. 4m 30s
    1. Welcome
      1m 14s
    2. What you should know before watching this course
      2m 33s
    3. Using the exercise files
      43s
  2. 7m 52s
    1. Installing V-Ray
      2m 27s
    2. Locating V-Ray tools and features
      5m 25s
  3. 39m 2s
    1. Creating natural daylight with the V-Ray Sun and Sky
      7m 41s
    2. Using the Omni Light
      7m 9s
    3. Exploring the Rectangle Light
      6m 2s
    4. Exploring the Spotlight
      4m 37s
    5. Exploring the IES light type
      5m 0s
    6. Setting up image-based lighting
      8m 33s
  4. 29m 40s
    1. Working with irradiance mapping
      12m 8s
    2. Creating a light cache solution
      6m 14s
    3. Using the DMC engine
      11m 18s
  5. 23m 11s
    1. Overview of the physical cameras
      5m 16s
    2. Understanding the Exposure controls
      6m 23s
    3. Handling perspective correction
      3m 4s
    4. Setting up for a depth-of-field effect
      8m 28s
  6. 44m 59s
    1. Introduction to V-Ray-specific materials
      9m 41s
    2. Creating diffuse surfaces
      9m 44s
    3. Creating reflective surfaces
      8m 2s
    4. Creating refractive surfaces
      9m 53s
    5. Creating translucent surfaces
      7m 39s
  7. 44m 8s
    1. Using fixed-rate sampling
      10m 21s
    2. Working with the Adaptive DMC engine
      11m 48s
    3. Controlling the Adaptive Subdivision sampler
      10m 15s
    4. Exploring subdivs and the DMC Sampler controls
      5m 52s
    5. Manipulating color mapping
      5m 52s
  8. 33m 39s
    1. Adding displacement to materials
      10m 48s
    2. Using caustic lighting effects
      7m 37s
    3. Creating occlusion effects
      8m 13s
    4. Creating a non-photorealistic render (NPR) with the Toon material
      7m 1s
  9. 1m 21s
    1. What's next?
      1m 21s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ.

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now "Already a member? Log in

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed SketchUp Rendering Using V-Ray.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferencesfrom the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.