rendering problem

[espanolo1]

trying to render a material using v ray , i used refraction at abouot 60 % so some of the colour still shows but when i render the material instead of coming up as a grey transparent material it comes up as a sort of checkerboard ie some parts completely clear then completely grey boxes thoughout the material , has anyone experienced this ?? is there a way to fix is using vray or 3dsmax or is this just something wrong with my PC ??

Thanks in advance

[RErender]

Sounds like flipped normals, is it modeled out of max?

[Lupaz]

It happend to me once. I think it has something to do with imported geometry.
There's a thread here somewhere.

[mokiloke]

also may occur when two faces are in the same plane ie on top of each other