Red Splotches appearing on refractive glass?

Problem - In Direct Light
http://www.cgvisions.com/temp/with\_sunlight.jpg

No Problem - Without Direct Light
http://www.cgvisions.com/temp/no\_sunlight.jpg

Does anyone have any ideas as to what might be causing this? I don’t think it’s the glass material, because it seems to be working well on other tables in my scene and without the sunlight turned on. I did not have “check sample vis” turned on when I calced this IR map, if that might be something? Could it be related to an object nearby the table, an object that is throwing off “invalid texture derivatives” errors in the render dialoge? I’m also getting somew overbright messages.

This shot was made in MAX/Vray1.47 - IR/QMC

Thanks for your help in advance - Dave

Could it be related to an object nearby the table, an object that is throwing off “invalid texture derivatives” errors in the render dialoge? I’m also getting somew overbright messages.

You can try deleting this object from you scene and see if the dots still appear. It may be the reason for sure.

Best regards,
nikki Candelero

It turned out it WAS that pesky couch object. It all kinds of strange thing going on with it and it was creating lots of errors in the vray dialogue box too. Now my dialogue errors and red dots are gone.

Could someone explain to me the science behind why this occurs?

most likely a material on it, that vray didn’t support.

No, the material was good. It was one of the first things I replaced on it. I think it was related to those “invalid texture derivitives” messages I was getting. Maybe some bounced rays off of those couch surfaces didn’t know where to go or how to behave?

Make sure the verts on the couch are all welded and that none are isolated.