Maya adjust game curve of shader?

malcolm · Jun 2011

Anyone know if there is a way to adjust where the terminator happens on a shader, I'd like to push it backwards from it's default so it is a smooth linear transition rather than having a realistic tight curve.

malcolm · Jun 2011

Shit I ment gamma curve of shader.

Warheart · Jun 2011

What shader are you using and what are you rendering with? If you could post an example screenshot of the type of shader you have and a photoshopped comparison showing what you want to achieve that would help to understand what you're trying to do.

It seems like an unusual thing to want to do adjusting the gamma on a per-shader basis. Not saying it's not possible but I suspect there will be a simpler way to achieve what you're looking for.

If you happen to be rendering with MR then the exposure node might be something like what you're looking for (although this works like a post process rather than per-shader).

malcolm · Jun 2011

I'll post a shot tonight, basically I want to soften the terminator of the shader to be extremely gradual, I believe the technical term for this is a half lambert. A ramp gradient texture controls the terminator rather than default curve of the shader.

Eric Chadwick · Jun 2011

BRDF ?
http://wiki.polycount.com/CategoryShaders

malcolm · Jun 2011

Sorry I should have mentioned I was looking for a mental ray shader.

Half lambert, sometimes called wrap light shader, or light wrap. It pushes the terminator backwards so a sphere receives more lighting past where the directional light hits it. It was the shader they invented for Stuart Little 2 to make the fur look better. I tried making this with a ramp shader in Maya, but it appears the terminator can't go into the negative, or maybe I just don't know how to make it that way.

http://developer.valvesoftware.com/wiki/Half_Lambert

http://forums.cgsociety.org/showpost.php?p=3198846&postcount=24

Eric Chadwick · Jun 2011

Not sure if this is what you;re after, but... Google... "mental ray shader half lambert"... 5th result...
http://www.derekjenson.com/2/category/rendering/1.html

malcolm · Jun 2011

I don't know what software that guy is using, but it's definitely not Maya or mental ray.

Warheart · Jun 2011

As far as I know you can't do that with the shaders that ship with maya. I totally understand why you would want that though. I did try making a quick fake SSS shader network a while ago and ran into similar problems.

I haven't really looked into it but I think this does what you're looking for:
http://www.pixero.com/files/JS_wrapmaterial.zip

malcolm · Jun 2011

Yep, that's the shader I'm looking for, but that shader does not support shelf shadowing and I need that feature too.

Warheart · Jun 2011

Well there's source code included with that shader. Time to start learning MR shader code it sounds like :P. Either that or find an interested programmer.

Maya adjust game curve of shader?

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