This page provides information on how the latest version of V-Ray handles scenes saved with previous versions of V-Ray.

 

Page Contents

 

Overview


V-Ray 3.0 adds a number of rendering optimization features. However, for compatibility reasons, these features are automatically turned off when loading scenes saved with previous V-Ray versions. These features are listed below.

Max ray intensity  This parameter is disabled when loading old scenes but is enabled by default for new scenes. See the Global Switches section for more details.
Probabilistic lights
  This feature is disabled for old scenes but is enabled for newly created ones. See the Global Switches section for more details.
Intel Embree
  T
his feature is generally disabled by default and must be explicitly enabled both for old and new scenes. See the System section for more details.

 

Brute Force Path Tracing Optimizations


The DMC system in V-Ray 3.0 has been modified to allow for more efficient brute force path tracing, especially where many GI bounces are used. In particular, V-Ray 3.0 uses a technique known as Russian roulette much more heavily for probabilistic sampling of many material and lighting effects. This technique was also used in previous V-Ray versions, but V-Ray 3 makes a much more extensive use of it.

The Russian roulette technique may introduce some extra noise in the result but allows many more samples to be computed. For this reason, some scenes may appear slightly noisier when rendered with V-Ray 3.0 compared to previous V-Ray versions and may need to be readjusted.

 

DOF and Motion Blur Subdivs


The subdivs parameters for depth of field and motion have been removed from the V-Ray UI (both in the main renderer and the physical camera), since the exact same effect can be achieved with adjusting the antialiasing settings of the Fixed and Adaptive image samplers. Scenes that use those parameters will need to be readjusted. The parameters are still accessible through MaxScript for compatibility with old scenes. The Adaptive subdivision image sampler has its own DOF/moblur subdivs.

 

Skylight portals and glossy reflections


Previous versions of V-Ray rendered skylight portals seen in glossy reflections slightly brighter than they should be. This is corrected for V-Ray 3.0, but may cause older scenes to appear slightly darker when glossy materials reflect skylight portals.

 

Support for mixing of V-Ray and Standard materials


Support for mixing of Standard and V-Ray materials (e.g. a Standard 3ds Max material inside a VRayMtlWrapper or inside a VRayOverrideMtl) prevented us from implementing some optimizations in the V-Ray code. In some cases, we had to drop support for mixing of Standard and V-Ray materials. Older scenes that used this combination may render incorrectly.