V-Ray Sampling Approaches

This tutorial presents three unique approaches to sampling in V-Ray 3 - each with their own benefits and drawbacks.

V-Ray's true strength lies in it's ability to optimize the sampling of a scene to render in a fraction of the time it would take an unbiased engine like Arnold to complete a scene. With the release of V-Ray 3, users are given an unprecedented level of control over how V-Ray performs the sampling of a scene.

We'll cover each approach in depth and allow you to choose which method is best suited for your needs. This wont be a complete rundown of sampling theory for beginners like my V-Ray Render Optimization tutorial, so a bit of experience with V-Ray is expected.

Text Goes Here.

Workflow:

1. In the Image Sampler (Antialiasing) rollout - set the image sampler type to Adaptive.
2. In the Adaptive Image Sampler rollout - set Min Subdivs to 1, Max Subdivs to 100, and check Use DMC Sampler Thresh.
3. Leave all other sampling settings at the V-Ray defaults.
4. Leave all other Subdivs values throughout your scene (Lights, GI, Materials) at their default value of 8.
5. Render your scene!
6. If less noise is desired, reduce the Noise Threshold value in the Global DMC rollout to a low value like 0.005.

Text Goes Here. [Compromise between the Universal Settings and Full Control methods.]

Workflow:

1. In the Image Sampler (Antialiasing) rollout - set the image sampler type to Adaptive.
2. In the Adaptive Image Sampler rollout - set Min Subdivs to 1, Max Subdivs to 100, and check Use DMC Sampler Thresh.
3. Leave all other sampling settings at the V-Ray defaults.
4. Leave all other Subdivs values throughout your scene (Lights, GI, Materials) at their default value of 8.
5. In the Image Sampler (Antialiasing) rollout - set the Min Shading Rate to a value of at least 4.
6. Render your scene!
7. Depending your scene, you can continue raising the Min Shading Rate value higher to reduce render time while increasing quality. You've found the sweet spot when your render time no longer decreases and begins to increase again.
8. If less noise is desired, reduce the Noise Threshold value in the Global DMC rollout to a low value like 0.005, and continue to raise the Min Shading Rate value accordingly.

Text Goes Here. [Opposite to the Universal Settings approach]

Workflow:

1. In the Image Sampler (Antialiasing) rollout - set the image sampler type to Adaptive.
2. Uncheck the Divide Shading Subdivs checkbox.
3. Set all secondary Subdivs values throughout your scene (Lights, GI, Materials) to a low value like 2.
   (A script like V-Ray Material Control is helpful for changing the Subdivs values throughout an entire scene with one click)
4. Following the step-by-step procedure outlined in my V-Ray Render Optimization tutorial, tune the Image Sampler (AA) Max Subdivs value to properly resolve the needs of your scene.
5. Once the AA is properly set, gradually increase the various secondary Subdivs values throughout your scene - starting with Lights, then GI, then Materials - to systematically eliminate any sources of noise.