POV-Ray : Newsgroups : povray.documentation.inbuilt : SOR documentation : Re: SOR documentation Server Time
15 Sep 2025 09:54:54 EDT (-0400)
  Re: SOR documentation  
From: William F Pokorny
Date: 8 Sep 2025 11:10:19
Message: <68bef1db$1@news.povray.org>
On 9/8/25 09:52, William F Pokorny wrote:
> I'll try and look at some of the other issues you mention as I have 
> time; Including temporarily removing the x>0.0 restriction on the first 
> and last points to see what happens. Aside: we did remove a similar 
> restriction for the lathe for v3.8 vs v3.7.

Well, the current code drops portions of the curve that get pulled into 
x<0 territory by control points x<0. See attached image.

Might be fixable / map-able to x>=0 as you, I think, were suggesting 
with the abs() comment. It might even acceptable as a final result, IF, 
the inside tests, normal calculations and uv mapping code map in a sane 
way to the result.

Thinking aloud, it might be possible to allow x<0 control points - ONLY 
- where both on curve points and off curve control points are forced to 
be always ascending (>= previous) in y. This, probably, would cover the 
'useful' x<0 control point cases while preventing the curve from 
crossing into -x?  I'll try to play with this thought some more when I 
again have time - need to run.

Bill P.


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