POV-Ray : Newsgroups : povray.advanced-users : Fake shadows in 32-bit images? : Re: Fake shadows in 32-bit images? Server Time
24 Sep 2021 04:08:28 EDT (-0400)
  Re: Fake shadows in 32-bit images?  
From: Kenneth
Date: 1 Sep 2021 00:20:00
Message: <web.612eff0e7599ad524cef624e6e066e29@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
>
>
> I also tried an 'object pattern' for the shadow (no matrix needed,
> just the negative vnormalize trick): I  pasted its created pigment on the front
> of a vertical box, then aligned/rotated the box using
> Point_At_Trans(<LS2.x,0,LS2.z>  It works, sort of...but the object-pattern
> operation is a bit odd (or rather, unexpected)-- the pattern seems to be derived
> from an infinitely thin slice of its object in the x/y (?) plane-- which leaves
> out any parts that do not overlap that plane:
>

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! 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 infinitely-tiny depth-scaling of the object pattern, for the
*entire* object to show up there.


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