V-Ray warning: Invalid geometric normal

[LL_Will_J]

V-Ray warning: Invalid geometric normal

I get this error from time to time on the warning log of my renders. I have the idea that my renders are going slower when it happens (although I could be imagining it!)

Does anyone know what it means and what I should be doing to fix the problem?

Many thanks

Will.

[LL_Will_J]

Apologies - I should have searched before posting (I always forget you are more likely to find the answer here than google!).

Anyone here is what Vlado explained previously. Seems like the increased render times are cause I always have SubD stuff when this occurs (which makes sense).

This usually happens when you use subdivision surfaces on models with errors like repeating faces, non-merged vertices, zero-area faces and the like.

Best regards,
Vlado