New Feature: Playlist Center! Pick a topic and let our playlists guide the way.

Start learning with our library of video tutorials taught by experts. Get started

SketchUp Rendering Using V-Ray
Illustration by Richard Downs

Exploring subdivs and the DMC Sampler controls


From:

SketchUp Rendering Using V-Ray

with Brian Bradley

Video: Exploring subdivs and the DMC Sampler controls

One thing you may have noticed when you first started using V-Ray for SketchUp is the prolific use of the term subdivs in many parts of the renderer's user interface elements. Understanding what that term refers to and how our numeric subdiv values will affect the quality of our final renders is, in my opinion, an essential piece of the puzzle regarding our ability to use V-Ray for SketchUp in a production environment. Now, as I am going to be talking about the rendering process, I just want to open up the Options Editor for ourselves so we have access to V-Ray's control parameters.
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

Watch this entire course now—plus get access to every course in the library. Each course includes high-quality videos taught by expert instructors.

Become a member
please wait ...
SketchUp Rendering Using V-Ray
3h 48m Intermediate Sep 21, 2012

Viewers: in countries Watching now:

Create highly realistic 3D architectural drawings with V-Ray, a popular third-party renderer for SketchUp. This course shows how to take a single scene with interior/exterior elements and add lights, move cameras, and enhance objects with translucent and reflective surfaces. Author Brian Bradley explains concepts like irradiance mapping, perspective correction, and fixed rate sampling, while showing how to leverage each of the V-Ray tools and its material and lighting types to achieve specific effects.

Topics include:
  • Installing V-Ray
  • Creating natural daylight with V-Ray Sun and Sky
  • Bouncing light around with irradiance mapping and light caches
  • Setting up a depth-of-field effect
  • Creating diffuse and reflective surfaces
  • Working with the Adaptive DMC engine
  • Manipulating color mapping
  • Adding caustic lighting and occlusion effects
Subjects:
Architecture Rendering CAD
Software:
SketchUp V-Ray
Author:
Brian Bradley

Exploring subdivs and the DMC Sampler controls

One thing you may have noticed when you first started using V-Ray for SketchUp is the prolific use of the term subdivs in many parts of the renderer's user interface elements. Understanding what that term refers to and how our numeric subdiv values will affect the quality of our final renders is, in my opinion, an essential piece of the puzzle regarding our ability to use V-Ray for SketchUp in a production environment. Now, as I am going to be talking about the rendering process, I just want to open up the Options Editor for ourselves so we have access to V-Ray's control parameters.

Whenever we start a render in V-Ray, we are really initializing the ray-tracing process. During this, our render engine collects information from our 3D scene by means of rays that are cast and then traced through that environment. Our image sampler, sometimes called anti-aliasing controls, are the ones that actually determine the number of primary or I rays that will be used during this process. However, depending upon the setup of our scene of course, secondary rays may also need to be traced.

Secondary rays are required to produce many of the blurry, or noisy, effects that ray-trace renderers such as V-Ray are so good at producing, effects such as blurry reflections, blurry refractions, depth of field, motion blur, area or soft-edge shadows, ambient occlusion, and well, quite a bit more. The number of secondary rays used to calculate these effects, for the most part, will be controlled by our subdiv values. This is why a Subdiv setting is present in so many V-Ray tools.

Something that is worth noting here is that the values we set in our Subdiv fields don't actually describe the number of samples being used to create a particular effect. Rather, they represent the square of them. So, a subdiv value of 8, which oftentimes is the default in many V-Ray tools, could more accurately be described as 8 multiplied by 8. That would of course give us a total of 64 samples, or rays, that could be used to create a particular effect in our scene, such as blurry reflections.

Now we used the word "could" very deliberately here, because there are actually another set of controls in V-Ray that will determine just how many of those potential 64 rays, or samples, are actually used in the final render. These controls are found in the DMC Sampler rollout. When creating blurry render effects, internally, the VRay renderer is making extensive use of a class of randomized computational algorithms that are known as Deterministic Monte Carlo, or DMC, algorithms.

This of course is a term that we've already encountered in our use of V-Ray. So, whenever it is that we see any of these noisy effects being rendered in a scene, well, DMC algorithms are being heavily utilized by V-Ray in that process. The brilliant thing about our DMC Sampler controls is that they allow us to tune just how finely our DMC algorithms work in these instances. For this reason then, many VRay users ask just what parameters should be used inside of the DMC Sampler rollout.

Well, of course every scene will have unique aspects that can and will affect pretty much every setting we use in VRay, including our DMC Sampler controls. So really, the best we can do is to give you some general-usage guidelines. Hopefully, these will serve as a foundation from which you can fine-tune each of your scenes. Generally speaking, for the most part, we can leave everything inside of the DMC Sampler rollout set at its default. Of course if we have a need to set a minimum number of subdivisions higher than the default setting, then we can most definitely do that.

But as we say, generally speaking, we can leave everything at its default in here and just work with this Noise Threshold value. This really can be used to switch between what I think of as draft and final render settings inside of our DMC Sampler. If we are working on test or preview renders, then Threshold values of between 0.1 and 0.01 are generally pretty good. These values mean that we will very rarely, if ever, make full use of the settings used in our Image Sampling and Subdiv controls.

What we will get, however, are very fast renders. When it does come time to create our final rendered output, well values of between 0.008 and 0.002 tend to work very well. In fact, my default starting point is a value of 0.005. From that, I then fine-tune my scene. These settings will allow V-Ray to make full use of the values that have been set in our Image Sampling and Subdiv parameters.

Of course, as with any increase in quality, we are bound to experience slowdown in our renders, but the images we get back will be extremely clean with regard to the blurry effects, or noisy effects that are contained within them. Now it has to be said that this brief overview of the Subdiv and DMC Sampler controls may be a little dry, a little bit technical for some, but we have to reiterate that the DMC Sampler plays a critical role in the V-Ray rendering process. All too often, it is tweaked just a little as an afterthought or maybe even ignored by many users.

Hopefully though, this brief overview of these controls will help you avoid making just such a mistake.

There are currently no FAQs about SketchUp Rendering Using V-Ray.

 
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.
Upgrade now


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 Upgrade now

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

Notes cannot be added for locked videos.

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.