Material ID Channel

Material Editor > Material ID Channel

The buttons on the Material ID Channel flyout tag a material as a target for a Video Post effect or a rendering effect, or for storing with a rendered image saved in RLA or RPF file format (so that the channel value can be used in a post-processing application). The material ID value is the counterpart of a G-buffer value for objects.

Zero (0), the default, indicates that no material ID channel is assigned.

A value from 1 to 15 means to apply a Video Post or rendering effect that uses this channel ID to this material.

For example, you might want a material to glow wherever it appears in the scene. The material is in the Material Editor and the glow comes from a rendering effect. First, you add a Glow rendering effect and set it up so that it operates on ID 1. Use Material ID Channel to give the material an ID number of 1, then apply the material to objects in the scene in the usual way.

To save the channel data with the rendering, use the RLA or RPF format.

Warning: The mental ray renderer does not recognize Z-depth with G-buffers. G-buffer data is saved on a single layer. Also, the mental ray renderer does not support the following effects:

Glow lens effect (rendering effect)
Ring lens effect (rendering effect)
Lens effects Focus filter (Video Post)

Procedure

To assign a material ID channel to a material:

Choose a channel number from the Material ID Channel flyout.

Note: Giving a material a nonzero ID channel number tells the renderer to generate a material ID channel containing that value. This information is stored in images only if you save the rendered scene in RLA or RPF format. However, the ID channel data is available to rendering effects at render time.