Problem with Blending

[htrustee]

I have a peculiar problem with blending:

I have two closed surfaces, one inside the other, so
if transparency is switched off, one only gets to see the outer surface. If i make both surfaces transparent, some triangles of the outer surface are transparent with respect to
the background, and some are not. Likewise for the
inner surface, so parts of the inner surface are visible
and some are not. Ideally, I should see the inner surface through the outer surface, but i see only parts of it.
Furthermore, this effect seems to depend on the viewing
angle, because at some angles the transparent surfaces
look o.k. and at others they dont.

[mikael_aronsson]

Hi !

Have you sorted the triangles ?, to get transparency to work, you must first render all non transparent triangles and then at the end you render all transparent triangles.

Mikael

[htrustee]

Originally posted by mikael_aronsson:
Hi !

Have you sorted the triangles ?, to get transparency to work, you must first render all non transparent triangles and then at the end you render all transparent triangles.

Mikael

No, i did not. The problem is, all triangles should be
transparent. So how do i know, which one to render first? To further complicate things, i have surfaces, which are closed and curved such that they cover parts of themselves. Here
again i have the problem, that parts of the surface, which cover some part of the surface now are transparent with respect to the background but not transparent with respect to the underlying triangles (which belong to the same surface).