View Full Version : soft shadows with mental ray lights

06 June 2009, 09:49 PM
I have a scene set up with a MIB spot light attached to a Maya spot light, which I need in order to get MR volume lights working for the spot. This defaults to hard shadows overriding the ray trace shadow settings of the Maya spot light. I have been able to get soft shadows on the spot by adding a MR area light, but this slows down my render quite a bit. Are there

a) any alternative ways to get soft shadows with MR lights?
b) a way to speed up the render times for the area lights?


06 June 2009, 04:41 AM
Let me pose my question differently:

In order to get a volumetric fog light (God rays) in mental ray I have needed to override the Maya lights with a mental ray light:

1) parti_volume in the volume shader for a polygon cube encompassing the whole scene (this makes a ray marcher which fills the cube with fog)
2) spot light with MR physical light in the light shader slot of the spot
(without this it does not seem to work!)
3) spot light in the light linking slot of the part_volume
(now the fog is only showing in the cone of the spot)
4) mental ray area lights checked in the mental ray section of the spot
(now I get soft shadows, but slow render times)

I know that's really convoluted. Blame mental ray for that one...

Anyhoo, my original thought was to find another way to get soft shadows with mental ray lights (in this case the physical light) besides using an area light which looks nice but renders super slow. No luck.

So now I'm wondering if there is a way to generate volume fog on a light without using a mental ray light (step 2 above) since this is what is overriding the nice soft ray traced shadows I would normally get without long render times on my spot light. Is there some way to omit step 2 above? Or some other approach to creating volume lights on a spot in mental ray?

I am concentrating really hard and mentally summoning Zap and Floze to this thread. Ich rufe Zap and Floze herbei aus dem Cyberweltall! Kommmmmmt. There, that ought to do it...

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06 June 2009, 04:41 AM
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