POV-Ray : Newsgroups : povray.general : 2D function to 3D tube : Re: 2D function to 3D tube Server Time
4 Feb 2023 01:46:43 EST (-0500)
  Re: 2D function to 3D tube  
From: Droj
Date: 6 Jan 2023 12:05:00
Message: <web.63b85430560d616820e7fc03b2af915@news.povray.org>
"Droj" <803### [at] drojde> wrote:
> I was interested to see how can a 2D curve get a more interesting life in a 3D
> world.
> And I found a promising approach in the Internet on B. Frassek's website
> https://www.frassek.org (sorry, the site is in German but an automatic
> translation is available). Look for 'function graph as pipe/tube'.
> The steps are outlined here:
>
>  - take the parametric function of a circle as cross section for the tube
>  - determin the gradient of the 2D curve you want to use (derivatives must
> exist)
>  - let the center of the cross section travel along the 2D curve (e.g. like
> insulation on a copper wire)
>
> Alas, that's it.
>
> So I started to adapt all the functions to Povray. I am aware that using atan2
> is an unexplicable mystery but what the heck.
>
> The result was sort of sobering as the tube was flatend in some parts and bulgy
> in others.
> I upload the POV-Script I generated to show the problem.
>
> Any suggestions (if there are any) on how to get a perfectly round tube are
> welcome but I need the parametric approach as I want to use the .inc/.obj output
> for more things to come.

Hi to all,

I guess this subject is rather exhausted.

Don't take me wrong I have the highest esteem for those who developed the
meshmaker macros and I am not happy to be the igorant, bloody user finding the
fly in the ointment - provided there is any as there is no proof.

Be assured the meshmaker macros work flawlessly with a heap of parametric
functions I tested.

My thanks to all who took part in this fruitful discussion and for actively
sharing their knowledge.

For the time being I will use Bill's solution to test some more curves and
produce interesting tubes including the .obj/.inc files.

And finally here's something I made in a jiffy - no great artistic work I admit.


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