

"Kenneth" <kdw### [at] gmailcom> wrote:
> Hmm, I was wrong about the object pattern itself it *is* actually a
> 3D/volumetric pattern, of the entire object given to it. That's rather neat!
Right. Essentially, POVRay just checks to see if the ray intersection point is
inside the object, and gives it the appropriate texturing.
http://www.flohmueller.de/pov_tut/tex/tex_560e.htm
> But
> the box object that I 'projected' the pattern onto happened to have its front
> surface exactly along the x/y plane (before I rotated it), so that's the only
> 'slice' of the pattern visible as the 'shadow.'
>
> So I attempted to 'squash' the object pattern in z by scaling it to try and
> get a more complete representation of the original object as the 'shadow' but
> that produced no useful result. Seems that an 'infinitely thin' box surface
> would require an infinitelytiny depthscaling of the object pattern, for the
> *entire* object to show up there.
What you can do is take the object and make it into an isosurface, then use that
function like: function {Object (x, y, 0)} which will scale the object
infinitely in the z direction.
But wait  there's more!
Now use that function in a pigment pattern, and you get a silhouette (shadow) of
the object.
Easy to do for cardinal axis aligned shadows, takes a little bit more to do
offaxis either by prerotating the object and then rotating the pattern back,
or maybe by doing some vector normal to a plane type stuff...
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