> I'm not sure what "hypertextures" are, but I think they have something
> to do with actually deforming the surface of the object. POV is a
> raytracer that traces most shapes directly, it doesn't reduce everything
> to triangles, so doing real deformation would require tesselating the
> objects into a triangle meshe or tracing curved rays.

I was just thinking how media works: a ray hits an object, several samples
along the ray are taken, and the light along the ray is calculated. This
takes time, but with GHz PCs...
Just thinking aloud: A ray hits an object (say, a sphere). A second sphere
which is a little smaller is tested against the same ray. Now I know a
finite segment of the ray that is inside the "boundary" of the sphere. I'd
apply a root solver to e.g. the leopard pattern plus the distance to the
inner sphere along that finite segment (I'm afraid this isn't even close to
being mathematically correct, I hope you can see what I mean...). So now I
have the intersection of a sphere with a "leopard" hyper-texture. Of couse
this is slow, but currently I'm using millions of spheres, which is probably
slower (at least as soon as windows starts swapping).
I don't have a clue what that would look like, really, but I could imagine
some interesting effects could be done with that...

> Are you talking about built-in
> isosurface functions for making displaced versions of the basic
> primitives, so a user defined function doesn't have to be interpreted?

Yes, close. Pigments like granite or ripples aren't interpreted either.
There's one thing isosurfaces can't do: you can't wrap them around a
height_field.
I also think wraping an isosurface around the boundary of a primitive should
be faster because the boundary is smaller than the whole object, so less
space has to be tested against some function etc.
Last but not least, you could build a scene with primitives (spheres,
cylinders, height_fields...) and test the "iso-textures" (?) separately on
some spheres, applying them the primitves when you got the geometry and
colouring right (that's exactly how I use the media and radiosity features
right now).
You could even build include files for often used "iso-textures" (I seem to
like that name) and apply them to any object you like (which is quite hard
with iso-surfaces)

Again, I can't say that often enough: What I'd like to do isn't fast, not at
all. However, if I'd like to do something like that with pov-ray right now,
I have to use uncounted triangles or spheres or isosurfaces which aren't
fast either, and are also a bit hard to use.

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