Hi:

From the error message I'm getting, I assume that a "solid mesh" does not 
qualify a what the "object pattern" expects as a "solid". Right? Any ideas 
on any alternative method for converting a mesh into an isosurface?

Thanks...

P.D.: the error was "Illegal texture or patch in clip, bound or object 
pattern".

-- 
Jaime Vives Piqueres

La Persistencia de la Ignorancia
http://www.ignorancia.org

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In article <3d8f8d13@news.povray.org>,
 Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:

> From the error message I'm getting, I assume that a "solid mesh" does not 
> qualify a what the "object pattern" expects as a "solid". Right? Any ideas 
> on any alternative method for converting a mesh into an isosurface?

Solid meshes should work fine in the object pattern, however, the object 
pattern is not suitable for isosurfaces. The object pattern has an 
infinite gradient at the surface of the object, the isosurface algorithm 
does not work well with this type of function.


> P.D.: the error was "Illegal texture or patch in clip, bound or object 
> pattern".

I don't know what that error means...maybe you are specifying a texture 
for the object.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:

> Solid meshes should work fine in the object pattern, however, the object
> pattern is not suitable for isosurfaces. The object pattern has an
> infinite gradient at the surface of the object, the isosurface algorithm
> does not work well with this type of function.

  Well, I've not arrived to that point... but I'm fearing most of all the 
render speed of this approach.

>> P.D.: the error was "Illegal texture or patch in clip, bound or object
>> pattern".
> 
> I don't know what that error means...maybe you are specifying a texture
> for the object.

  In my case I think it means "Illegal patch in object pattern". I can use 
whatever except a mesh (solid). And I'm sure it has no texture: it's a file 
generated by Clothray, and I revised it carefully. I tried even with a 
little solid mesh created by hand and still got the "illegal patch" error.

  Anyhow, I must think on another solution. Even if it worked, this is too 
slow for a human life... 

-- 
Jaime Vives Piqueres

La Persistencia de la Ignorancia
http://www.ignorancia.org

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Jaime Vives Piqueres wrote:
> 
> Hi:
> 
> From the error message I'm getting, I assume that a "solid mesh" does not
> qualify a what the "object pattern" expects as a "solid". Right? Any ideas
> on any alternative method for converting a mesh into an isosurface?

As Chris Huff explained the object pattern won't work for that purpose
anyway.  

There is a. 'IC_Triangle()' macro in IsoCSG:

http://www-public.tu-bs.de:8080/~y0013390/pov/ic/docu02.html#Triangle

and ABX is working on an IC_Mesh(), but that won't be very fast (in fact
incredibly slow for large meshes).

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______

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Christoph Hormann wrote:

> As Chris Huff explained the object pattern won't work for that purpose
> anyway.

  Well, I don't understand very well why, but I trust you both. :)
 
> There is a. 'IC_Triangle()' macro in IsoCSG:
> and ABX is working on an IC_Mesh(), but that won't be very fast (in fact
> incredibly slow for large meshes).

  That mesh *is* large. Anyhow, don't worry: I just discovered that I was 
trying to do a very stupid thing that makes no sense... but I will never 
admit it, of course. ;)

-- 
Jaime Vives Piqueres

La Persistencia de la Ignorancia
http://www.ignorancia.org

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in news:3d8f8d13@news.povray.org Jaime Vives Piqueres wrote:

> Any ideas 
> on any alternative method for converting a mesh into an isosurface?
> 

Make a solid mesh, cut it up it in thin slices, build a df3-file of the 
slices and use it in an isosurface. You may also want to use some focal 
blurr on the slices so the gradient for the isosurface won't be too high.

Ingo

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On Tue, 24 Sep 2002 10:19:54 +0200, Christoph Hormann <chr### [at] gmxde>
wrote:
> There is a. 'IC_Triangle()' macro in IsoCSG:
>
> http://www-public.tu-bs.de:8080/~y0013390/pov/ic/docu02.html#Triangle
>
> and ABX is working on an IC_Mesh(), but that won't be very fast (in fact
> incredibly slow for large meshes).

There is more important limitation than speed. Finite number of constants for
functions engine. Even simple famouse teapot balances on limit border in my
experiments.

ABX

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ABX wrote:
> 
> There is more important limitation than speed. Finite number of constants for
> functions engine. Even simple famouse teapot balances on limit border in my
> experiments.

Does the hard coded triangle function help there?

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______

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On Fri, 27 Sep 2002 10:25:43 +0200, Christoph Hormann <chr### [at] gmxde>
wrote:

> ABX wrote:
> > 
> > There is more important limitation than speed. Finite number of constants for
> > functions engine. Even simple famouse teapot balances on limit border in my
> > experiments.
>
> Does the hard coded triangle function help there?

Partially. It decreases number of floats but not eliminates it. So while mesh
can be as big as memory, iso_mesh can be as big as floats stored as contants
in virtual machine.

ABX

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ABX wrote:
> 
> Partially. It decreases number of floats but not eliminates it. So while mesh
> can be as big as memory, iso_mesh can be as big as floats stored as contants
> in virtual machine.

That's what i assumed.

There are probably more useful approaches generating an isosurface
function based on mesh data anyway, see for example:

http://www.cc.gatech.edu/gvu/geometry/implicit/modeling.html

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 13 Aug. 2002 _____./\/^>_*_<^\/\.______

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