why not have someone export a cylinder as a mesh for you from a program
that can and then use it as an include file?  i think meshes parse
faster and take less memory for your situation.  you could still use
your program to place them, you would just have to put the object name
in place of the cylinder.

Simon Lemieux wrote:
> 
> >   Perhaps instead of doing it the hard way (ie. program your own raytracer,
> > which probably won't be any better than povray), you could just try to
> > optimize your scene for povray.
> >
> >   If povray spends ages calculating light buffers (and that's what is filling
> > up the memory), try turning them off. The rendering may be slower, but if
> > it was the actual problem, it will render, which is the goal. You can also
> > try with the vista buffers as well (although I don't know if it will be of
> > any help).
> >
> >   If your scene has many identical groups of cylinders (the only difference
> > between the groups being the transformations (scale, rotate, translate)
> > applied to them) you could try replacing the cylinders of one of these group
> > with equivalent smooth triangle meshes (making a #declared identifier of them).
> > When you make copies of this mesh (and transform the copies) they will take
> > a lot less memory. The bigger the group of cylinders and the more the copies
> > of the group, the better (ie. more memory saved).
> >
> >   If your texture doesn't have to be transformed with the cylinder (but is,
> > for example, just a plain color), don't texture each cylinder separately,
> > but make a union of all the cylinders in the scene and texture it just once.
> 
> IMHO,
>         POV-Ray is a complete general raytracing algorythm...  which will be fast
for
> almost anything...
> 
>         My scene has no light, nothing else than a few millions of cylinders all the
> same texture...  how can I optimize that for povray? Reduce the number of
> cylinders? Wrong!  That would also reduce the realism of my scene... what I need
> is a raytracer that would handle very easily and very fast such a big number of
> "Cylinder" and would be simply very slow when you would only have a cube...
> Optimized for a large number of cylinders, that is what I need!  Also that I got
> a C++ program that calculate the position for all these cylinders and outputs
> the result in a povray script...  ( cylinder { <x,y,z> texture { TheTex }})  and
> then povray starts Parsing the scene and takes forever...  Would take a double
> forever if I added lighting!...
> 
>         I am very interested in Povray, but sometimes I would need a specific
tool...
> 
> Thanks,
>         Simon
> 
> --
> +-------------------------+----------------------------------+
> | Simon Lemieux           |            http://www.666Mhz.net |
> | lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
> +-------------------------+----------------------------------+

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Simon Lemieux <lem### [at] yahoocom> wrote:

> My scene has no light, nothing else than a few millions of cylinders
> all the same texture...  how can I optimize that for povray? Reduce the
> number of cylinders? Wrong!  That would also reduce the realism of my
> scene... what I need is a raytracer that would handle very easily and
> very fast such a big number of "Cylinder" and would be simply very slow
> when you would only have a cube...  Optimized for a large number of
> cylinders, that is what I need!  Also that I got a C++ program that
> calculate the position for all these cylinders and outputs the result
> in a povray script...  ( cylinder { <x,y,z> texture { TheTex }})  and

If all cylinder objects have the same texture why do you apply this
texture to each object? I would rather make a union and apply the
texture to the whole union object.

bye,
  Chris
-- 
Christian Perle              E-mail:        chr### [at] tu-clausthalde
Am Galgensberg 4             WWW:        http://home.tu-clausthal.de/~incp/
38678 Clausthal/Germany      ComputerGuitarKitesBicyclesBeerPizzaRaytracing

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> If all cylinder objects have the same texture why do you apply this
> texture to each object? I would rather make a union and apply the
> texture to the whole union object.

I tried that...  the only thing it helped was to reduce the size of the file a
few kbytes... big deal... didn't speed anything up...

BTW, I could use something like opengl... but one day... my cylinders might
become glass cylinder and then I would like to be able to do some refraction... 
impossible with opengl... only possible with a raytracer... and then again I
talked about Millions of cylinder...  one day I might need Billions and so
on...  Adding hardware to help the process isn't a solution, I must change the
process itself...

Thank you all for your suggestions, but what I need is documentation about
"creating a raytracer"...  

Thanks,
	Simon

-- 
+-------------------------+----------------------------------+
| Simon Lemieux           |            http://www.666Mhz.net |
| lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
+-------------------------+----------------------------------+

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again, why not use a mesh?  in megapov they are solid and could be
glass.

Simon Lemieux wrote:
> 
> > If all cylinder objects have the same texture why do you apply this
> > texture to each object? I would rather make a union and apply the
> > texture to the whole union object.
> 
> I tried that...  the only thing it helped was to reduce the size of the file a
> few kbytes... big deal... didn't speed anything up...
> 
> BTW, I could use something like opengl... but one day... my cylinders might
> become glass cylinder and then I would like to be able to do some refraction...
> impossible with opengl... only possible with a raytracer... and then again I
> talked about Millions of cylinder...  one day I might need Billions and so
> on...  Adding hardware to help the process isn't a solution, I must change the
> process itself...
> 
> Thank you all for your suggestions, but what I need is documentation about
> "creating a raytracer"...
> 
> Thanks,
>         Simon
> 
> --
> +-------------------------+----------------------------------+
> | Simon Lemieux           |            http://www.666Mhz.net |
> | lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
> +-------------------------+----------------------------------+

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I told you many ways of optimizing the scene. Did you read my article
completely?

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

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Simon Lemieux <lem### [at] yahoocom> wrote:
: BTW, I could use something like opengl... but one day... my cylinders might
: become glass cylinder and then I would like to be able to do some refraction... 
: impossible with opengl... only possible with a raytracer... and then again I
: talked about Millions of cylinder...  one day I might need Billions and so
: on...  Adding hardware to help the process isn't a solution, I must change the
: process itself...

  Billions of glass cylinders? Stop dreaming :)

  Well, perhaps if you have a render farm consisting of hundreds of Cray T3E
computers with 2048 processors each and gigabytes of memory and running a
multithreaded patch of povray...

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

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Hi,

>nothing else than a few millions of cylinders

On my whole screen there is not even one single million of individual
pixels and I don't think there are many around with "a few million"
pixels, let alone enough to show a few million instances of anything
larger than a single pixel.

Ciao, MM
-- 

http://www.marian-aldenhoevel.de
Opinions expressed here are my own AND those of my employer

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> 
> Hi,
> 
> >nothing else than a few millions of cylinders
> 
> On my whole screen there is not even one single million of individual
> pixels and I don't think there are many around with "a few million"
> pixels, let alone enough to show a few million instances of anything
> larger than a single pixel.

Good point.  Simon: beware of aliasing.

-Mark Gordon

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In article <399EA958.52093EC9@yahoo.com>, lem### [at] yahoocom says...

> impossible with opengl... only possible with a raytracer... and then again I
> talked about Millions of cylinder...  one day I might need Billions and so
What is the point of using so much objects? Unless you 're wanting to 
render it at VERY high resolutions, they simply can't show up in your 
scene, as there is more than one object per pixel... And probably the 
objects in the front hide an enoumous amount of objects in the back.
You should really reduce the amount of objects. If you optimize it the 
right way it should show no difference at all in the resulting image.

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On Sat, 19 Aug 2000 13:24:16 -0700, ryan constantine wrote:
>again, why not use a mesh?  in megapov they are solid and could be
>glass.

There's a common misconception here.  An object need not be solid to be
made of glass.  I've made glass boxes from meshes and even bicubic patches.
The trick is to make sure every transparent face of the object is associated
with the same interior{ } block.

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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