Shadows only light

[KyronVFX]

Is there a way to create a shadows only light in Vray? In Mental Ray you can give a light a black color and a negative value for the shadow color, to have the light cast only shadows.

I also noticed that Vray does not seem to support volume lights. I know theyre not the most used, but they can be pretty handy to "suck" out light from specific areas.

I'm sure there are workarounds for both, but I just can't seem to figure out how to do it.

Thank you.

[vlado]

Is there a way to create a shadows only light in Vray? In Mental Ray you can give a light a black color and a negative value for the shadow color, to have the light cast only shadows.

You can do a similar thing with V-Ray; you can't keep the light black though - you'll need to give it some small non-zero intensity and set the cut-off threshold to 0.0. Negative shadow color is ok.

I also noticed that Vray does not seem to support volume lights. I know theyre not the most used, but they can be pretty handy to "suck" out light from specific areas.

You can use the VRayEnvironmengFog for this - attach some spherical shape to it and turn down the fog color itself to black so that it doesn't reflect light.

Best regards,
Vlado

[djorzgul]

Somehow I cannot reproduce this workflow.

I have two spot lights. One for illumination, one for shadows. When I lower the intensity on the "shadow" light and set negative value for the shadow color, I don't get desired result.
So, I guess I am doing something wrong.
1. My negative value for shadow color is -1 ( white, if default color is black?), and shadows are white. Am I defining shadow color in a wrong way?
2. When I leave shadow color to be black, I get weak shadows, since light intensity is .01
3. If I put some other color, red for eg, intensity is good, not pale as when they're black.

The only reasonable thought I have in my head at this moment is to have render element shadow pass, and to adjust shadow intensity/colors in compositing process.

[vlado]

What lights are you using? My test was with V-Ray lights.

Best regards,
Vlado

[djorzgul]

I used maya lights ( spot) with added V-Ray att. to change cutt-off value.
I'll try it with V-Ray lights.

[KyronVFX]

Hey Vlado.
Sorry for late reply. I will do a test once my boss gets off my back