Dear all,
Been having problems with light leaks. Geometry is from autocad file linked to max. I threw a shell modifier on the geometry to see if that might help, but it didn’t.
What can I do to resolve this? Settings are Irradiance map and Light Cace 90/80 medium preset, - lc 1200 subdivs, pre-filter 50 - adaptive DMC 1-50
Is it just crummy autocad geometry? Or are my settings amiss?
Try checking either “Check Sample Visibility” in the IM settings or “Retrace threshold” in the LC settings.
Cheers! I can’t see retrace threshold in LC? - Running 1.5 SP4A here.
then just “check sample visibility” in IM then
Did that - upped the DMC to 1/100 - lowered the shadow bias on the sun. Still the problem persists. How do people get those super-clean interior renders?!
I think it may be autocad producing crap geometry. I’ve never liked geometry from cad being brought in to max, except when I throw an edit mesh on it and delete it 
I tried putting a box in behind the offending area, and still the light leaks through.
Am I right in adjusting the shadow bias? Should I up the subdivs of the sun?
Try using a subdivide modifier on your mesh. I’ve seen this a few times with v1 of vray and that always seemed to help.
Try BF/LC real quick on a region and confirm it’s IMAP (which it certainly looks like it is). Use a box block geometry object for a quick solution, or play around with your nrm threshold, etc in imap settings.
I’ve had a similar problem, and it was due to “store direct light” being on in the LC.
I very much doubt it has anything to do with the CAD geometry. Unless it was modelled with surfaces instead of solids