glass shadows in mental ray
 

is there a trick to get a glass object like a window to stop casting opaque shadows when using mental ray? I have made the glass transparent but it always casts an opaque black shadow. What might I be doing wrong? Im attaching an example.

makes sure all of your lights are using Ray Traced shadows. D map shadows wont work.

in that image above raytrace shadows is turned on. I checked the spotlight and its ray trace attribute is on. Im lost. What else could it be?

can you post a bigger image of the trouble spot? i think i know whats wrong.

heres a closer shot.

yeah. i think i know why, with the galss at an angle it diffuses more light. this is whats causing the dark shadow. try not shining your primary light from straight above.

hmmm... Ill give it a shot....

nice model...poly?

all polys.. There are some more recent shots in WIP forum. Thanks for the compliment. BTW... I havnt rerendered the model since iron tick mentioned the shadow thing but I looked again at some of my renders and as the window bends around in the front the shadow does appear to be working correctly. Ill give it a try later and see for sure. thanks again.