Well, I found *another* possible POV-Ray bug when I tried my demonstration
test using PPM for the image map. POV-Ray (at least v3.5 on Windows) appears
to generate PPM files using binary encoding, and can't read its own output
files when used for input image map files. When I generated a PPM file in
step one of my demonstration test and tried to use the outputted file
imagefile.ppm in step two, I got the following parse error:

image_pattern {ppm "imagefile.ppm" <----ERROR
Parse Error: Unsupported number of colors (0) in PPM image.

> There is no point in trying to investigate in a problem if it does not
> exist in the current code.

Could you please explain that statement? If there is a problem in the
binaries that are out in the field, what good is it to test a reported bug
in your development code (source code to which common users do not have
access)? Sure, it proves that the next version of POV-Ray won't have the
problem, but until *we* have the new version, it doesn't do us users much
good, does it? And it does nothing to verify my proof that the current
version of POV-Ray has a memory problem with loading image maps over and
over again in long-running animation sequences, which Thorsten has flatly
stated is untrue.

"Christoph Hormann" <chr### [at] gmxde> wrote in message
news:fo4### [at] tritonimagicode...
> Scott Gammans wrote:
> >
> > If you're not going to use the generally-released version of POV-Ray
that's
> > available to the user community, that's not a valid basis for
comparison,
> > is it?
>
> There is no point in trying to investigate in a problem if it does not
> exist in the current code.
>
> > And if the problem truly is in the PNG library subsystem, rendering
> > with ppm does nothing but confirm that the problem isn't in ppm.
>
> Which is exactly the point i was trying to make.  If there is a memory
> problem in the png library this is something completely different.  You
> can either use a different file format or try to get a libpng programmer
> fix it.  I doubt anyone here will bother to dig into libpng internals.
>
> Disclaimer: i have no idea if there indeed is a memory problem with png
> writing or not.
>
> Christoph
>
> -- 
> POV-Ray tutorials, include files, Sim-POV,
> HCR-Edit and more: http://www.tu-bs.de/~y0013390/
> Last updated 25 Oct. 2003 _____./\/^>_*_<^\/\.______
>

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