VFB Channels Overview
V-Ray provides its own channels or render elements for the purposes of image compositing.
VFB channels - In order for V-Ray to render individual channels you must select the desired channel from the pick list. The list of supported render elements is below.
Black - If you are using the Z-Depth render channel, this parameter signifies the z-value where the buffer color will turn to black.
Clamp - when enabled z-values should be clamped to the range of black to white.
White - If you are using the Z-Depth render channel, this parameter signifies the z-value where the buffer color will turn to white.
Set from camera - this will automatically set the z-depth range based on the camera setting.
List of Supported Render Elements
The following render elements are supported by V-Ray. All render elements support native V-Ray materials. Some render elements also support standard Rhino materials. This is noted in the table below.
|Render element name||VRayMtl support||Std material support||Filtering control||Transparency support||Description|
|The image background.|
|VRayBumpNormals||yes||yes||yes||no||The normals generated by bump maps|
|The caustics on the material. Only present when the Caustics option of V-Ray is enabled. This channel does not include GI caustics.|
|VRayDiffuseFilter||yes||yes||yes**||yes||The pure diffuse surface color. Note that this is different from the standard 3ds Max Diffuse render element, which contains the diffuse surface lighting.|
|VRayGlobalIllumination||yes||no*||yes**||yes||The diffuse surface global illumination. Only present if Global illumination is enabled.|
|The diffuse direct surface lighting.|
|VRayMatteShadow||yes||yes||yes||yes||The matte shadow part of the image|
|VRayMtlID||yes||yes||no (always off)||no||The material ID of the object.|
|no||The surface normals.|
|VRayRawGlobalIllumination||yes||yes||yes**||yes||The raw diffuse global illumination (not multiplied by the diffuse surface color). Only present if Global illumination is enabled.|
|The raw diffuse direct illumination before it's multiplied by the diffuse surface color.|
|The pure surface reflection before it's multiplied by the reflection filter color.|
|The pure surface refraction before it's multiplied by the refraction filter color.|
|VRayRawShadow||yes||no||yes**||yes||The raw light that was blocked by other objects.|
|VRayRawTotalLighting||yes||no||yes||yes||The sum of all raw lighting - direct and indirect|
|VRayReflection||yes||yes||yes**||yes||The reflections on the surface.|
|VRayReflectionFilter||yes||no||yes**||yes||The reflection filter (the color by which the raw reflections are multiplied to give the final surface reflection). This may be considered as an alpha channel for the reflections.|
|The refractions on the surface.|
|VRayRefractionFilter||yes||no||yes**||yes||The refraction filter (the color by which the raw refractions are multiplied to give the final surface refraction). This may be considered as an alpha channel for the refractions.|
|VRayRenderID||yes||yes||no (always off)||no||The node render ID of the object that contributes most to the pixel value.|
|VRaySamplerRate||N/A||N/A||N/A||N/A||Shows an image where the pixel brightness is directly proportional to the number of samples taken at this pixel.|
|VRaySelfIllumination||yes||yes||yes**||yes||The self-illumination of the surface.|
|VRayShadow||yes||no||yes**||yes||The diffuse light that was blocked by other objects.|
|VRaySpecular||yes||yes||yes**||yes||The surface specular highlights.|
|VRayTotalLighting||yes||yes||yes||yes||The total lighting in the scene - direct and indirect|
|VRayZDepth||yes||yes||yes||no||The z-depth of the surface.|
* For Standard materials, the VRayLighting element includes the direct and indirect lighting as well as caustics, while the VRayGlobalIllumination and VRayCaustics elements are black. However for all materials, adding the VRayLighting, VRayGlobalIllumination and VRayCaustics elements always gives the total diffuse surface lighting.
- V-Ray always antialiases with respect to the RGB color channel. Therefore other channels may appear jagged or noisy in areas where V-Ray has placed fewer samples.
- Render elements will render in Distributed rendering mode.
- Render elements require additional storage when rendering and thus increase the amount of RAM taken during the rendering. When rendering to the V-Ray VFB, you can reduce this memory by rendering directly to a .vrimg file on disk and not storing the final image in memory.
- Render elements may slow down the final image rendering a little bit, depending on the number of elements that the user has selected. They have no effect on GI/reflection etc. calculations.