[Radiance-general] strange artifacts

[Francesco Anselmo]

Hi all!

I'm experiencing a strange problem:
http://www.bozzograo.net/radiance/pub/artifacts.jpg

I'm exporting the model of a curved glass with vertex normals
to obj and converting it into a radiance mesh.
I'm using the dielectric material with it, so the glass object has two
surfaces (inner and outer side of glass), but I can't get rid of this
strange effects at the edges, where the quads become triangles.

The remaining part of the surface is fine, even at the center,
where there are some other triangles. I need to subdivide the polygons
many time before this effect becomes less noticeable ...

Any ideas?

Thanks!

-- 
Francesco