POV-Ray : Newsgroups : povray.advanced-users : Bezier spline deformation : Re: Bezier spline deformation Server Time
3 Jun 2023 10:29:34 EDT (-0400)
  Re: Bezier spline deformation  
From: William F Pokorny
Date: 22 Mar 2023 09:07:31
Message: <641afd93$1@news.povray.org>
On 3/22/23 05:05, yesbird wrote:
> The problem is in different results of splines rendering in C4D and POV, 
> I can't even imagine how it could be.

A bit of wild guessing. In looking some at font rendering code years 
back, I noticed what looked like bezier spline p1-c1-c2-p2 incoming 
point sets being converted to p1-p1_2((c1+c2)/2)-p3 and then the 
duplicate end points getting compressed. The resulting point list was 
then rendered with via cubic_spline.

The why of all it then, I do not know. But, if I do that conversion on 
your bezier_spline point list and create an equivalent cubic_spline of:

#declare Extrude2 = prism { linear_sweep cubic_spline 0, 1.000000, 11
    <0.975347, -0.725347>
    <1.500000, 0.000000>
    <0.975347, 0.725347>
    <0.000000, 1.000000>
    <-0.975347, 0.725347>
    <-1.500000, 0.000000>
    <-0.975347, -0.725347>
    <0.000000, -1.000000>
    <0.975347, -0.725347>
    <1.500000, 0.000000>
    <0.975347, 0.725347>

I get the attached image using an orthographic camera and if not a match 
for what c4d is showing in your last post, it looks to me to be in the 

Bill P.

Post a reply to this message

Download 'yesbird.png' (4 KB)

Preview of image 'yesbird.png'


Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.