Hi,

> real world remotely like this. The closest thing would be an ior
> variable over space, which POV is incapable of doing (and which would

I don't care about IOR. I just want a thing like thick fog. However, same
problem of course.

> take a huge amount of time if it was capable). Are you sure you need for
> each triangle to have its own interior?

Almost. Each group of approx. 100 to 1000 triangles may have the same
interior. But in relation to a total count of several millions of triangles
this is similar to "each triangle".
However, the whole object is one, single, huge mesh (for speed reasons).

> There is an object behind it. That gives POV a finite interval to sample
> the media in. In the areas where only the background is visible, the ray
> goes off into infinity, and POV can't sample it. Put a big, hollow
> sphere around your scene, and things will be more predictable, though
> still not realistic...lone triangles aren't very useful for media
> containers.

I see. So the interior statement is misleading incase of triangles since it
is no interior. It is like a switch to turn on interior calculation if it
hits the triangle until it hit an other object, rather than an interior of
the triangle (which one would think if entering the POV statement).

> You don't have to duplicate nature entirely, just use closed meshes.
> Closing the mesh shouldn't add that much in complexity.

Uhm. It would at least double the amount of triangles an I already have
millions of them.....
We'll see. Would it be enough just to create each triangle twice with a
small offset between them? According to my latest tests I think so.
Fortunately this would have a further advantage (beside the working media
and the doubled amount of data): The objects could have a front and a flip
side with different textures. I once thought about it.


Just one further question:
If I store millions of triangles in a mesh it is not a big problem since
meshes store triangles efficiently and build a hierarchical octree of the
structure. This speeds up tracing.
Will I lose this if I switch to a union of triangles? (since interior
doesn't work on triangles in meshes). Will tracing speed decrease and memory
usage increase??

thanks a lot,
regards
SY

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