mental ray glass mullions - black overlap

[batfink82]

Im rendering a lobby shot which has glass mullions, the viewppoint is quite close to the mullions looking into the space. because of this the mullions all overlap and evenutally they render black - not good.

 

I have increased the number of bounces in both the ai material and in the trace depth.

 

I am using MAX 2009 with mental ray, the scene is lit with a daylight system.

 

Does any one have any ideas how I can overcome this problem, the mullions only start turning black when there are about 4-5 overlapping.

 

Any ideas welcome!!

 

Many thanks,

 

Toby

[jinsley]

"... I have increased the number of bounces in both the ai material and in the trace depth. ..."

 

If you increase the number of bounces to a high enough number in the indirect illuminaiton tab (final gather and gi) make sure that in the renderer tab, the trace depth is 1 unit more... this will ensure that the maximum number of bounces are used.

 

If you keep increasing the tace depths for relfections, etc... eventually you should get rid of the black. Count the number of polys that the raytracer needs to cross and this should give you a good starting point.

[mattclinch]

or if you don't fancy processing a lot of unnecessary calculations , just select the mullions and other glass and in the properties dialog under the mentalray tab, make the geometry invisible to GI and 'pass-through' for FG.

[jinsley]

or if you don't fancy processing a lot of unnecessary calculations , just select the mullions and other glass and in the properties dialog under the mentalray tab, make the geometry invisible to GI and 'pass-through' for FG.

 

+1 That's even smarter... damn.

[batfink82]

thanks guys, i have tried hiding from making invisable to GI and pass through for FG but I still get the black at the very end of the lobby space where there are about 40 mullions overlapped...........I guess I can try upping the depths further.

[jinsley]

Can you post an image??? Can you shift the camera slightly left or right to solve this problem physically, rather than by playing with the render settings?