POV-Ray : Newsgroups : povray.general : Most efficient way to code a hemisphere (lathe.inc) : Re: Most efficient way to code a hemisphere (lathe.inc) Server Time
29 Jul 2024 14:13:38 EDT (-0400)
  Re: Most efficient way to code a hemisphere (lathe.inc)  
From: Trevor G Quayle
Date: 26 Feb 2011 23:25:00
Message: <web.4d69d15336e168b6b05ef170@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
> Am 27.02.2011 03:08, schrieb gregjohn:
> > Hi. I was trying to find the most efficient way to code a mesh for a perfect
> > hemisphere.  I could probably do it if I were to break out a while loop with a
> > couple thousand entries in the spline based on trig functions.  But it would
> > really help to know the simplest way to define one.  So far I haven't hit on it
> > with quadratic spline, supposed I will next try cubic.
> >
> > TIA for any help.
>
> Forget it - you can't get a perfect arc section from cubic (or
> lower-order) splines. As for the other fancy splines in POV-Ray, they're
> actually just cubic splines in disguise.



The best way (outside of just using a sphere object) would be a rationally built
and calculated mesh.  The basic math for a hemisphere is simple, the most
difficult part is organizing the points into faces.

-tgq


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