Is there any converters to go back to dxf or other 3d file formats ?

I am using a molecule viewers that generates vrml or .pov files.


Thanks

Charles

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Charles & Paula wrote:
> 
> Is there any converters to go back to dxf or other 3d file formats ?
> 
> I am using a molecule viewers that generates vrml or .pov files.
> 
> Thanks
> 
> Charles

The short answer is no. If you want the long answer let me know.

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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As far I understood how are the .pov files, there are made of spheres, lines
and triangles with a colour, position in the space, etc. Why these
attributes can't be transfered in an other file format ?
Maybe I'm wrong in my believes ?

Thanks

Charles

Ken wrote:

> Charles & Paula wrote:
> >
> > Is there any converters to go back to dxf or other 3d file formats ?
> >
> > I am using a molecule viewers that generates vrml or .pov files.
> >
> > Thanks
> >
> > Charles
>
> The short answer is no. If you want the long answer let me know.
>
> --
> Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Charles & Paula wrote:
> 
> As far I understood how are the .pov files, there are made of spheres, lines
> and triangles with a colour, position in the space, etc. Why these
> attributes can't be transfered in an other file format ?
> Maybe I'm wrong in my believes ?

Ok the long answer. The main problem is parsing the povray language used.
In modelling programs and most 3D file formats there are very strick rules
about the placement and attributes of an object. Povray on the other hand
has many different methods of describing an objects shape, location,
and it's attributes. None of these are very rigid and in fact one of the
major attractions of POV-Ray is this flexibility in describing an objects
attributs.

A common question that arises is why doesn't the program Moray have the
ability to directly import .pov files or why has no one written a conversion
program to parse .pov files. Since I answered this question quite recently
for someone else I will simply include my replies to these questions here.

////////////

 What you need to understand is the complexity of the conversion process.
In order for Moray to be able to read .pov files you would essentially
have to build a Pov language parser into Moray that is equal to the
language parser already available *AS* POV-Ray. I have talked with the
author or Moray and he is not happy with the idea of adding that much
overhead to the program plus the complex programming task involved. It
just is not as simple as you would think or it would have been done already.

 To make it as a stand alone conversion program still has the problems
associated with writing a program what will parse the Pov language
and then convert it into a format that Moray would recognize. Again
it is not a weekend project that just anyone could do. It would take
someone with as much experience as the programmers of POV-Ray to write
such a parser and there are few of those around that have time on
their hands for this type of work. In fact if someone actually did
write such a program they would likely want to be paid for it instead
of offering it for free like many of the other Pov related utilities
are.

////////////

  In the above examples you can substitute Moray with just about any
3d format that you choose because the explaination is fairly consistent
for all 3d file formats. Povray uses mathimatical objects. Most other
3D formats use the location of vertices for triangles that make up the
object. Again it is not an easy conversion process and in some cases
is simply not possible at all.


I hope this satisfies your curiosity.

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Charles & Paula <pcd### [at] cybercablefr> wrote:
: As far I understood how are the .pov files, there are made of spheres, lines
: and triangles with a colour, position in the space, etc. Why these
: attributes can't be transfered in an other file format ?
: Maybe I'm wrong in my believes ?

  Ken gave you an excellent answer.
  Besides that I would like to emphasize that in povray only meshes, triangles
and bicubic patches are made of triangles. Everything else are mathematical
objects.
  There are even objects that can't be represented with a finite number of
triangles (like many polynomials which form an infinite surface). Finite
objects can always be approximated with triangles but some of them are not
trivial to convert.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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