POV-Ray : Newsgroups : povray.general : min_ and max_extent of an intersection object : Re: min_ and max_extent of an intersection object Server Time
15 Jul 2024 20:52:17 EDT (-0400)
  Re: min_ and max_extent of an intersection object  
From: Thorsten Froehlich
Date: 26 Jun 2020 03:10:01
Message: <web.5ef59e96a14394982945efad0@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> "Note: This is not perfect, in some cases (such as CSG intersections and
> differences or isosurfaces) the bounding box does not represent the
> actual dimensions of the object."
>
> The hell it doesn't!
>
> So, I am left with the good old trial-and-error finding of the right
> dimensions/locations of intersection objects. Not a big deal afaiac ;-)
>
> Still, I have been wondering if there would be other, smart, ways to do
> the same? And - just out of pure curiosity - why do min_extent and
> max_extent not work with intersections or differences? Where isosurfaces
> are concerned, I can imagine indeed...

LOL, the problem is so much simpler: This is a patch added from the old MegaPOV,
and all it does is provide access to the internal bounding boxes POV-Ray uses to
speed up rendering. Of course, a perfect bounding box does not matter as much
for this purpose, and the bounding in POV-Ray was never well optmised.

In fact, for CSG is is mostly additive (for the most part the biggest box
bounding all objects) and for isosurces you do actually provide the bounding box
via contained_by .

Thorsten


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