POV-Ray : Newsgroups : povray.general : .povray to .stl or other "CAD usable format"? Server Time
1 Nov 2024 01:22:55 EDT (-0400)
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From: formpig
Subject: .povray to .stl or other "CAD usable format"?
Date: 28 Mar 2014 14:10:00
Message: <web.5335b9cce2e1f758816540cd0@news.povray.org>
hi all,
is it possible to get a .povray file to stl or some other CAD usabe format?
if not, is it possible to get some kind of advanced user explanation so i can
understand why this can not work?
any knowledge or advice is appreciated.
- formpig


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From: Jaime Vives Piqueres
Subject: Re: .povray to .stl or other "CAD usable format"?
Date: 29 Mar 2014 06:53:22
Message: <5336a622$1@news.povray.org>

> hi all,
> is it possible to get a .povray file to stl or some other CAD usabe format?
> if not, is it possible to get some kind of advanced user explanation so i can
> understand why this can not work?

   Just look at the responses to your former post on p.advanced-users...

--
jaime


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From: Alain
Subject: Re: .povray to .stl or other "CAD usable format"?
Date: 30 Mar 2014 13:37:30
Message: <5338565a@news.povray.org>

> hi all,
> is it possible to get a .povray file to stl or some other CAD usabe format?
> if not, is it possible to get some kind of advanced user explanation so i can
> understand why this can not work?
> any knowledge or advice is appreciated.
> - formpig
>
>

ALL primitives, exept for mesh, in POV-Ray are NEVER represented as a 
mesh. They are purely mathematicaly based objects.

A sphere, for example, is a surface defined as: Sqrt(x^2 + y^2 + z^2) = 
radius.
A plane is truely INFINITE and defined by it's normal and distance it 
passes from the origin in the direction of it's normal. How can you 
represent such a surface in any format that only rely on triangles?



Alain


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From: scott
Subject: Re: .povray to .stl or other "CAD usable format"?
Date: 31 Mar 2014 04:20:54
Message: <53392566$1@news.povray.org>
> hi all,
> is it possible to get a .povray file to stl or some other CAD usabe format?
> if not, is it possible to get some kind of advanced user explanation so i can
> understand why this can not work?
> any knowledge or advice is appreciated.

Just to make a couple of points clear:

STL is a mesh based format, if you look close enough you'll see that 
everything is made from straight-edged triangles. STL is not normally 
used with CAD packages for exactly this reason. If you import an STL 
file to CAD you'll find you can't do much with it, as the CAD software 
will recognise it only as a million tiny triangles, not as a solid made 
of curved surfaces.

POV, along with 3D CAD packages, uses a smooth mathematical equation to 
describe every shape, no matter how far you zoom in or scale the shape 
it's still smooth. STEP or IGES files are typically used to send data 
between CAD packages, they are made up of mathematically defined 
surfaces, not triangles.

In theory a converter could be written for STEP<>POV that would exactly 
convert most POV objects, however there would be a lot of maths involved 
in figuring out the equations of surfaces after complex CSG operations. 
This is what CAD software does, but costs $$$ usually. It would be 
easier to convert POV SDL to some CAD scripting language, but why would 
you want to do that? It's easier to design in CAD than POV, and POV is 
better at rendering the outcome, usually people convert *from* CAD to 
POV, not the other way.

If you really want an stl file for some specific purpose, then take a 
look at OpenSCAD. The syntax is similar to POV SDL, and it will let you 
export an stl file (STEP output is on the wish-list).


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