POV-Ray : Newsgroups : povray.general : Sweeping circle along catenary curve Server Time
25 Nov 2024 04:23:02 EST (-0500)
  Sweeping circle along catenary curve (Message 1 to 3 of 3)  
From: ratneshmadaan
Subject: Sweeping circle along catenary curve
Date: 28 Apr 2016 14:55:00
Message: <web.57225c575b2354ee292a95ac0@news.povray.org>
(One day old to povray)
I want to render catenary wires (will assume them to be plain in texture)
There's an old, but useful thread for rendering catenary chains here
http://news.povray.org/povray.binaries.images/thread/%3Cweb.42f332855de03cffa196ebe30%40news.povray.org%3E/

I modified the code, and basically instead of torus links, with alternating 90
degree rotation, I made them cylindrical with no rotation. However this is a
naive way to extrude.

How can I do this? Basically use polygon
sweep(http://www.povray.org/documentation/view/3.6.2/62/) along an array of 3D
points got by solving for a catenary


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From: Alain
Subject: Re: Sweeping circle along catenary curve
Date: 29 Apr 2016 22:11:25
Message: <5724144d@news.povray.org>

> (One day old to povray)
> I want to render catenary wires (will assume them to be plain in texture)
> There's an old, but useful thread for rendering catenary chains here
>
http://news.povray.org/povray.binaries.images/thread/%3Cweb.42f332855de03cffa196ebe30%40news.povray.org%3E/
>
> I modified the code, and basically instead of torus links, with alternating 90
> degree rotation, I made them cylindrical with no rotation. However this is a
> naive way to extrude.
>
> How can I do this? Basically use polygon
> sweep(http://www.povray.org/documentation/view/3.6.2/62/) along an array of 3D
> points got by solving for a catenary
>
>

If you want a simple, plain, wire, then you can use the sphere_sweep 
primitive.
If you use the cubic_spline, you use the code to generate points 
starting one step before the first point and ending one step after the 
last point. As the cubic_spline interpolation give you a smooth curve, 
you don't need many points, something like 10 to 20 points should be 
enough in most cases.
Check the documentation about sphere_sweep.


Alain


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From: ratneshmadaan
Subject: Re: Sweeping circle along catenary curve
Date: 5 May 2016 10:30:01
Message: <web.572b57bc7cac95668bfd5e7f0@news.povray.org>
Alain <kua### [at] videotronca> wrote:

> > (One day old to povray)
> > I want to render catenary wires (will assume them to be plain in texture)
> > There's an old, but useful thread for rendering catenary chains here
> >
http://news.povray.org/povray.binaries.images/thread/%3Cweb.42f332855de03cffa196ebe30%40news.povray.org%3E/
> >
> > I modified the code, and basically instead of torus links, with alternating 90
> > degree rotation, I made them cylindrical with no rotation. However this is a
> > naive way to extrude.
> >
> > How can I do this? Basically use polygon
> > sweep(http://www.povray.org/documentation/view/3.6.2/62/) along an array of 3D
> > points got by solving for a catenary
> >
> >
>
> If you want a simple, plain, wire, then you can use the sphere_sweep
> primitive.
> If you use the cubic_spline, you use the code to generate points
> starting one step before the first point and ending one step after the
> last point. As the cubic_spline interpolation give you a smooth curve,
> you don't need many points, something like 10 to 20 points should be
> enough in most cases.
> Check the documentation about sphere_sweep.
>
>
> Alain

Hey thanks for the help. Before I saw this, I came across a rope macro and
modified that heh
http://news.povray.org/povray.binaries.images/thread/%3C4a1e679e@news.povray.org%3E/


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