POV-Ray : Newsgroups : povray.bugreports : bump maps inverted in spherical warp : Re: bump maps inverted in spherical warp Server Time
25 Feb 2024 08:00:10 EST (-0500)
  Re: bump maps inverted in spherical warp  
From: pkoning
Date: 4 Aug 2021 10:25:00
Message: <web.610aa29bfbcfb68e1e101ef1b9aee0ac@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
> Am 03.08.2021 um 22:19 schrieb pkoning:
> > I'm using a normal with a bump map, wrapped around a sphere using
> > warp{spherical}.  It looks normal in the northern hemisphere, but the bumps are
> > changed to depressions in the southern.
> This is a known issue that has been around for... well, ever since
> warped bump maps were first introduced, I guess.
> Sometimes the bumps even seem to turn "sideways".

And sometimes it doesn't happen.  Before today I haven't noticed it, though I
may have overlooked it.  In earlier tests I was using a plain texture instead of
the "cells" pattern, and then I don't remember seeing it.

Just  now I tried to reproduce it but I'm seeing a different baffling issue:
when I take out the "cells" pattern and replace it by a reference to a plain
texture, the parser complains that the "warp" modifier is not expected.  See

Possible Parse Error: Unmatched {

 line 100
Parse Error: No matching }, warp found instead

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