Mental Ray Translation System

When rendering a scene using mental ray 3ds Max performs a translation of meshes, materials, texture maps, etc. to mental ray formatted data for use by the mental ray renderer. The translation system allows a mapping to be done between a 3ds Max plug-in and an existing mental ray shader. In some cases you can use the default mental ray material. If no compatible mental ray shader exists, you will have to write one. For information on writing mental ray shaders consult the mental ray reference documentation provided with the 3ds Max.

3ds Max natively provides translation support for the various scene element types described in the mental ray rendering topics in the 3ds Max user documentation. The 3ds Max mental ray interface allows the developer to implement the translation of additional materials, texture maps, and geometry through their own custom translation mechanisms.

The mental ray translation system can be used to do the following:

Translate a texture map plug-in to a mental ray shader.
Translate a material plug-in to a mental ray generic material, or to a mental ray material phenomenon.
Translate an object plug-in to a geometry shader

Some examples of cases when the mental ray translation system would be useful are:

A developer has written a 3ds Max procedural texture map, and wants to make that map work with both of 3ds Maxâ€™s scanline and mental ray renderer. To do this, the developer writes a corresponding mental ray shader and implements the translation from the procedural texture map to this shader, allowing the map to render in both renderers. Note: this requires implementing a MR shader, please refer the reader to the mental ray reference documentation for this.
A developer has written (or acquired) a mental ray shader. The mental ray shader has a complex set of parameters which is difficult to handle with the UI created automatically by 3ds Max. The developer can instead create a texture map plug-in for 3ds Max, which will serve only as a UI handler, and use the shader translation system to translate this UI proxy to the mental ray shader.

Samples

The following samples demonstrate the techniques described in this section to support custom translation of 3ds Max data to mental ray formatted data.

The Default mental ray Material Phenomenon - \samples\mentalyray\mrmaterial
This is the implementation of the mental ray material. It makes use of material/map browser filters to only accept valid "apply types" on each shader button, and it implements shader translation to translate the 3ds Max material into the "mr_default_mtl_phen" material phenomenon.
Shader List Shader -\samples\mentalyray\mrshaders
This is the implementation of the shader list shader. It makes use of the material/map browser filters to only accept valid apply types, and it implements shader translation to translate its list of shaders into a list of mental ray shaders.