(Wow, returning to the PoV scene after a few years. 3.5 IS OUT!)

Due to various (programming/lazyness-related) reasons, i think i might
output SDL with a LOT of isosurfaces instead of normal objects and CSGs. I
was wondering  what kind of performance hit i could expect for a very
isosurface-heavy scene (extreme possibility: the whole scene is an
isosurface), compared to a more normal way of describing the same scene.

Which brings the following suggestion: Would it be possible to allow PoV to
interface with another executable(DLL/object file, etc) and use that
isntead of an interpreted function? Or does it seem doable to precompile
functions into assembly or a preparsed format instead of reparsing
everything (if that isn't done already)?

Thank you,
 Paul Khuong

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On Sun, 13 Jul 2003 18:12:55 EDT, "Paul Khuong" <p v k s p a
m### [at] pvkremoveobviousca> wrote:
> Due to various (programming/lazyness-related) reasons, i think i might
> output SDL with a LOT of isosurfaces instead of normal objects and CSGs. I
> was wondering  what kind of performance hit i could expect for a very
> isosurface-heavy scene (extreme possibility: the whole scene is an
> isosurface), compared to a more normal way of describing the same scene.
>
> Which brings the following suggestion: Would it be possible to allow PoV to
> interface with another executable(DLL/object file, etc) and use that
> isntead of an interpreted function? Or does it seem doable to precompile
> functions into assembly or a preparsed format instead of reparsing
> everything (if that isn't done already)?

If you think about adding DLL just for making CSG via isosurface then look at:
http://www-public.tu-bs.de:8080/~y0013390/pov/ic/ . If you think about adding
DLL support to POV-Ray you can of course do it for yourself since POV sources
are available but please note it is not prefered method of adding functionality
(for various reasons, mainly portability) and it was discussed many times. If
you think about adding some other internal functions, look into sources of
MegaPOV 1.0 for all places marked with F_TRIANGLE_PATCH. Reading
http://megapov.inetart.net/manual/internals.html can be helpful as well.

ABX

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In article <web.3f11d967e9867461c0e4f1850@news.povray.org> , "Paul Khuong"
<p v k s p a m### [at] pvkremoveobviousca> wrote:

> instead of reparsing
> everything (if that isn't done already)?

What makes you believe isosurface functions need to be parsed every time
they are evaluated?  Did you try to find out more about isosurfaces before
speculating how they work? - You really should, it will save you lots of
time!  I would recommend to read the many threads about isosurfaces you find
in these newsgroups to find out more.  They contain tons of useful
information.

There is no general answer how fast a scene with isosurfaces will be.  You
have to make the scene and test it.  It depends on so many factors, there is
no general answer.

    Thorsten

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