View Full Version : What am I doing wrong? GI and transparency...

03 March 2006, 10:03 AM
By now I'm banging my head against the wall, I just can't get mental ray
to render transperant materials properly with GI?! It just ignores that the
material is set to transperant and treats it like a solid objekt, and by now
it feels like I've tried just about everything to get it to work? What am
I doing wrong, I'm using Maya 7 and I don't have any problems with
rendering transperacy with just MR, but it just wont work with GI...

Some help please? ;)

03 March 2006, 10:52 AM
In the GI area of the Render Settings you need to tick the option called (something like) `direct illumination effects'.


03 March 2006, 11:25 AM
Well thanks, but I've tried that one already ;) And when I turn that option on it
seems like the photons manage to pass the object as they are suppose to.
But I still don't get the proper shadows while a third of that object (a glass shelf
located in a bathroom) lies in shadow...

In the GI area of the Render Settings you need to tick the option called (something like) `direct illumination effects'.


03 March 2006, 03:44 PM
try increasing the GI reflect/refract/ trace depth values in the GI section of Render Settings...

03 March 2006, 05:08 AM
What kind of shadows are you using? raytraced or shadow maps?
If you are using shadow maps, go to the render globals, under the shadows, change Shadow Maps to Detail, and see if it works.
Hope it helps:thumbsup:

03 March 2006, 08:46 AM
Don't forget that you most likley have to connect the shader as a photonshader also. (or use a separate one)
And use caustics as you are dealing with refractions.
And GI and Cau requiers photons to be emitted right?
But that is only from the top of my head.

03 March 2006, 10:38 AM
Thanks for the fast replies, my problem was a combination
of "Direct illumination shadow effects" not being checked and that one
of my spots "Ray depth limit" was set too low, doh! ;)

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03 March 2006, 10:38 AM
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