Hi Thorsten,
Indeed in my rush to aid Matthias I wrote #declare... instead of #macro....

The documentation of course says you cannot use #macro definitions in
layered textures, but like many rules in life it is in fact not a hard a
fast one. Using macros in layered textures has been a very useful way for me
to create versions of the standard POV-Ray texture include files that
support both my older assumed_gamma of 2.2 scenes and my new assumed_gamma
of 1.0 scenes.

I adopted this approach based upon a recommendation Ive made about a year
ago as a way to cope with the fact the shipped textures do not work well if
you try and use the recommended assumed_gamma  of 1...  I had been running
with an assumed_gamma of 2.2 for YEARs because it was all that seemed to
work with shipped textures.

To any who might also have been confused by this quirk of the standard
includes - get to where you ALWAYS use an assumed_gamma of 1. Adjustments to
textures are easier and simply make more sense. The resultant images have a
better fidelity that could probably be measured if I wanted to bother, but
it is obvious.

Unfortunately, the supplied textures and any others you might have created
so they look good on your non-apple system - without adjustment - and to
work with the supplied textures will need to be adapted to run with an
assumed_gamma of 1. A painful change, but well worth it.The illegal use of
macros happens to make adapting easier.

I know it is hard sometimes for you Thorsten and the other POV-Ray experts
to deal with us fools - but keep after us and eventually we'll get it!

Thanks again for catching my error.
Bill

"Thorsten Froehlich" <tho### [at] trfde> wrote in message
news:41bd5c64$1@news.povray.org...
> In article <41bd01dd$1@news.povray.org> , "William Pokorny"
> <pok### [at] attglobalnet> wrote:
>
> > An issue I have hit a few times is that the SDL interpreter seems to
have
> > trouble with macro definitions after the first inside say a layered
texture.
> > Something like this:
> >
> > #declare A_MACRO = {...}
>
> This is not a macro, it is a declaration!
>
> The limitations and pitfalls of layered texture declarations are explained
> in the manual.
>
>     Thorsten
>
> ____________________________________________________
> Thorsten Froehlich, Duisburg, Germany
> e-mail: tho### [at] trfde
>
> Visit POV-Ray on the web: http://mac.povray.org

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