Spot Light To Drive A Color Ramp?

[jsarclight]

OK, I've never been asked to do this before and I'm not sure how to accomplish this.

A Max user in our office has asked to be able to "drive a color ramp with a spotlight" in a maya scene he is working in. He says in Max you can have a spotlight drive a color falloff on a shader and he wants a similar effect. I've been toying with a few things but I can't get it work right.

In effect what we need to do is have a single linked spot drive a color falloff between color A and color B on a ramp so when the light is shining on the object from any direction (the light will move) the colors fall off from bright to dark on the object based on the direction the light is coming from.

[tobym]

Cheers,

ingredients are:

1 surface luminance node
1 set range node
a vRamp node
a shader node of your choice

plug the surfaceLuminance.outvalue into the setRange.inputValueX
plug the setRange.outputValueX into the ramp.vCoord
plug the ramp.outColor into yourShader.color

in the setRange Node put oldMax and Max to 1.0 and oldMin and Min to 0.0

et voila - bon appetit.

PS: I think if there is more than one light in the scene you'll have to fiddle around with lightlinking

[jsarclight]

Yep, that does it. I was -almost- to this point when this post came in.

I took it out a slightly different door and used a Clamp node between the SurfaceLum and the Ramp, then I connected the LightData of a spot to the LightDataArray of the SurfaceLum to give my artist the "only driven by one spotlight" thing.

Seems to work well and he loves it. Thanks for the help!

[joojaa]

Yes theres a alternative methodl wich is to plug out color of a perfectly white any shader node to the ramp instead of surface luminance node. Thisway you could have specular on it too, opr different normal direction etc etc...