This is a legacy documentation space! Please refer to V-Ray Next for 3ds Max for most up-to-date information.

This page provides information on V-Ray compatibility with G-Buffer output.

 

Page Contents

 

Overview


V-Ray supports multi-layered G-Buffer output required for writing .rla and .rpf files, as well as by many 3ds Max render effects. V-Ray will automatically generate the G-buffer channels requested by the image output and the render effects so there is no need to select these manually.


Supported G-Buffer Channels


This is a list of supported G-Buffer channels in 3ds Max.


3ds Max Channel Name

Supported by V-Ray

Description

Z

YES

Depth buffer (distance to the camera XY plane).

Material Effects

YES

The material ID.

Object

YES

The object node ID that is set through the Properties dialog of an object.

UV Coordinates

YES

The surface UV coordinates. V-Ray will always output the UV coordinates for mapping channel 1.

Normal

YES

The surface normal relative to the camera.

Non-Clamped Color

YES

The real unclamped pixel color, before any color mapping is applied to the pixels. Like with the scanline renderer, this channel does not store atmospheric effects.

Coverage

YES

The contribution of an object to the image pixel.

Node Render ID

YES

A unique ID assigned to each node by the renderer.

Color

YES

The material color for the object. Like with the scaneline renderer, this does not include any atmospheric effects.

Transparency

YES

The material transparency for the object. Like with the scanline renderer, this does not include atmospherics.

Velocity

YES

The surface velocity relative to the camera.

Sub-Pixel Weight

YES

The contribution of an object to the image pixel including transparencies.

Sub-Pixel Mask

NO

A bit mask for the contribution of an object to a pixel. The Sub-Pixel Mask channel is meaningless when AA filters, depth of field, and motion blur are taken into consideration, which is why V-Ray does not support it.


 

Notes


  • V-Ray takes antialiasing filters into account when generating the G-buffer channels, in contrast with the default scanline renderer of 3ds Max. This may cause differences in the way some render effects work. If this is a problem, turn off the AA filter from the Image sampler rollout. Also, avoid using AA filters with negative components (Catmull-RomMitchell-Netravali) when generating a G-buffer; 3ds Max cannot handle layers with negative coverage and V-Ray will ignore those when creating the 3ds Max G-buffer.
  • Generating a correct multi-layer G-buffer requires extra memory. This is because the 3ds Max G-buffer only supports scanline-style writing. However, V-Ray renders in buckets and cannot provide the data in scanline order. To work around this, V-Ray stores all the G-buffer data while rendering and then writes it at once into the final image.
  • G-Buffer layers are now generated correctly in distributed rendering mode. This means that render effects like image motion blur will now work in DR mode too.