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LennO
10-23-2003, 11:07 PM
Ok, my first post here…and it start with a problem…damn, i wanted to show ya some artwork, but this is more important currently ;)

Mental ray runs great for me, until it comes to custom MR shaders like DGS or SubScatter.

For example: I've never had to use blurred reflections in maya before but recently i wanted to try it out, without using the 3rd party shading node. So i re-read the manual chapter about the dgs shader, and applied it in the material slot of the shading groups mental ray tab. But mental ray only renders out black, regardless how i change the values. Is there anything i have forgotten?

The same problem occurs when i use subscatter, which i downloaded today. I add it to my SG, but MR reners black sometimes it just takes a second to render and it's black, and somtimes it takes a while, like it would actually do something…but , you guess it, the rendering is black, and the alpha is clear (pure black) too. I tried using batch rendering, but it gave me the same results…anyone knows what kind of problem that might be. Maybe I've overlooked one little option?
lazzhar
10-23-2003, 11:35 PM
like you I was just curious today and try it today but it works fine for me. try read this :
http://www.cgtalk.com/showthread.php?s=&threadid=61073
From the long list of Mental Ray Custom Shaders chose "DGS Material" , there is another one cannot remember its exact name which gives black reslults.
Good luck.
brunner
10-23-2003, 11:46 PM
You need to connect the lights to the dgs shader.
In hypershade drag the light on the dgs shader (NOT the shading group, the shader), and connect the "message" (or miExportMRlight,something like that) to the "lights" parameter on the right.
brunner
10-23-2003, 11:50 PM
Oh, and if you want to have blurred refractions, use the dgs shader, too ;)
Just be careful to increase the raytracing depth (once i spent a couple of hours trying to figure out why the hell my transparent shaders were rendering all black.. guess what: the raytracing depth was set to 1 :D)
LennO
10-24-2003, 11:02 AM
Thanks for your replys!

lazzhar:
I already read that…and thought i had done everything i had to do…obviously i did not ;)

brunner: It worked! I read in the manual about the Light Array variable in the DGS_Material Shader but since i didn't see anything like a light list in the shader node, i thought it wasn't important! Thanks!

SubScatter still doesn't work, but i read about the problems with it in the other threads, so that might not only be a problem that only i have.
lazzhar
10-24-2003, 10:27 PM
Just explained in the link it works for me, I'm lucky :p
brunner
10-24-2003, 11:00 PM
Just explained in the link it works for me, I'm lucky
The indirect illumination (GI/FG) works without linking lights, only the direct illum does not
lazzhar
10-24-2003, 11:16 PM
I meant just using DGS Shaders. It works fine for me. I didnt mention any GI/FG. I'm rather in rendering some glossy reflection.
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