clipka <ano### [at] anonymousorg> wrote:

> And that's where the problem with UV-mapped textures arises: Since
> `trace` knows nothing about textures, and `eval_pigment` knows nothing
> about geometry, the two can only be combined for good effect if there is
> a direct mapping between geometry and pigment via 3D XYZ space. But with
> UV-mapping that's not the case, and hence the /combo/ of the two
> functions breaks down there.

So, the color of a surface on a uv-mapped object is not directly measurable by
the eval_pigment() function? [ ! :O ]
I would never have guessed that.

It must then use a completely different algorithm than the ray-object
intersection used to generate the final scene.

Can you:
1. use trace() to get the point and the normal
2. define a pigment constructed in the plane intersecting that point with the
same normal
( I likely have no idea what I'm talking about here: I'm just confabulating the
possibility that some slice of a function-object-pattern thing might be a
workaround... )
3. then do an eval_pigment() on the plane?

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