Emit diffuse emit specular with MR shader

[caretz]

the only way I found is to render in passes or per light...
would be nice to be able to use the option embended in maya lights

-A

[Chadrik]

in order for emit diffuse and emit specular flags to work the material shader must be written to look for those attributes on the light. so the only way to do it would be to edit the shader code and recompile.

-chad

[caretz]

that s a big limitation for mental ray
I have to setup few more passes just for that but I am working on a script that spits out all the contribution per lights ...
anyone knows if maya 8 MR shaders are able to read those lights flags?
or they add those flags to the MR lights?

[ACamacho]

IT's a real pain I will admit. But for now a workaround I have been doing is creating two MR shaders (a lambert and the other a blinn/phong/ward/etc.) and adding the specular shader(diffuse color set to black) via an plus/minus node or a mix8Layer.

Then linking whatever lights I want to the specular shader (via the "lights" list in the shader). Hope I make sense. :) Works like a charm but requires alot of planning beforehand. It's worse when you have to link the specular lights to many many many shaders....but a simple loop script can work around that issue.

Or the other option is to use Maya shaders. ;)


as to why the shaders are like that, I've been told it's because the maya shaders compute both the specular and diffuse functions seperately....while the MR shaders compute them as one. Might be totally off base though.

*edit*: eek just realized the original poster started this thread almost a year ago. Oh well hope it helps.

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