We have a situation where we would like to have mattes generated for materials seen in a reflection or refraction.
I know mental ray can do this but I am forced to use the Autodesk framebuffer system. And for the life of me I can't wrap my brain around how to get it to work (if it's even possible in Maya)
For example: I have a light bulb being rendered behind another lens. The lens generates its own passes and mattes correctly (it is seen directly by the camera) But I would like the light bulb seen through the lens refraction as a matte written to its own matte pass buffer (the one it writes to when seen directly)
Ideally, RGB mattes. Red = directly visible matte, Green = matte from reflection, Blue = matte from refraction, but I will accept at least some sort of matte initially.
A rayswitch does not do this for me. Instead it just gives me the red matte when it is directly seen by the shader. Now, I know the shader is being run because it's seen through the lens. But it doesn't write to its buffers unless it's seen directly. Technically that makes sense, it's the lens cover being rendered even though the lens sees the bulb. But I still need bulb information.
Any ideas on how to achieve this with built in tools? Is my question clear? I can include a pic of what I am getting versus what I want too.
Maya 2012, mr 184.108.40.206, Windows 7 64-bit