Rune wrote:

> So what you're looking at is the resulting value; in other words the colour
> value seen by the camera.

No, I'm looking for the value BEFORE it's finally affected by the
projection system.

> The problem is, it doesn't make sense. You can't separate the resulting
> colour of pigment, normal and finish from each other, because they're all
> dependent on each other and on external conditions.

finish value depends, amongst other things, on normal (normal of the 
object's surface + normal {..} perturbation).  That's the only 
inter-dependance.  They don't "depend on each other".  Pigment and
normal are independant from each other and from finish, and finish
is independant from pigment.

Oh, BTW, interior {ior} depends on normal perturbation (it
affects the refracted ray).  Would you, because of that, put
the "interior" statement inside the "texture" statement ?

> > (and, BTW, ambient and diffuse shouldn't be in finish, since
> > they are view-independent)
> 
> Well there you go. Where should they go then, if not in the finish? 

Good question.  Historically, "finish" has been fed with many
features that didn't fit elsewhere.  "crand" is an example of
that.  ambient, diffuse and brillance might go into a separate
statement, (maybe "lighting") which describes how the surface
reacts to light.

You know, I don't intend to criticize, and the current system
works fine, but some design flaws are there, and are worth
discussing, especially in the perspective of future enhancements.

> And what is it anyway that makes you think that finish =
> view-dependent?

I explained myself in great lenghts about that.

> No. A pigment has a colour no matter if there's any light_sources (or
> cameras) or not. But you can only see it if there's light and camera.

I can ask POV-Ray to retrieve it and put the rgb value on-screen,
without even rendering !  I can do the same (with a macro) for the
normal perturbations.  However, I can't do it for finishes.  If
you can, tell me how.

> Similarly, a finish has a reflection value etc., 

A reflection AMOUNT, which, with a camera, light, and object, can
result into a rgb value at a given point.

> > Pigment and normal have an independent value, which is,
> > later, affected by environment.
> 
> No, you can't see your pigment if there's no camera and light_sources.

See above.  I can retrieve the value.

Fabien.

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