Hi,
	I've played with povray for a long time now and I realize that it's not
optimized for the kind of render I'm doing...  I mean povray takes forever to
parse a few millions of cylinders that have the same texture...  Yes, I know a
few Millions is a very huge number and should simply require more memory, but
povray crashed after filling my 128M of RAM and my 256M of swap...

Here I go...  I would like to make my own raytracer, not based on any point of
povray...  and optimize it for my own work...  but I never tried to make one and
I'm entering college for the first year this september,  what I was looking for
by posting this news is a list of books I should read in order to have a better
knowledge of this subject...  I prefer book over URL-documentation (unless
there's a .ps or .pdf i can print...)...

I already got a hand on Computer Graphics: Principles and Practice (Foley,
vanDam), but then, I would need some more!

Thanks a lot,
	Simon
-- 
+-------------------------+----------------------------------+
| Simon Lemieux           |         http://connect.to/666Mhz |
| lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
+-------------------------+----------------------------------+

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i think the 'graphics gems' series covers all kinds of graphics
including raytracing.

Simon Lemieux wrote:
> 
> Hi,
>         I've played with povray for a long time now and I realize that it's not
> optimized for the kind of render I'm doing...  I mean povray takes forever to
> parse a few millions of cylinders that have the same texture...  Yes, I know a
> few Millions is a very huge number and should simply require more memory, but
> povray crashed after filling my 128M of RAM and my 256M of swap...
> 
> Here I go...  I would like to make my own raytracer, not based on any point of
> povray...  and optimize it for my own work...  but I never tried to make one and
> I'm entering college for the first year this september,  what I was looking for
> by posting this news is a list of books I should read in order to have a better
> knowledge of this subject...  I prefer book over URL-documentation (unless
> there's a .ps or .pdf i can print...)...
> 
> I already got a hand on Computer Graphics: Principles and Practice (Foley,
> vanDam), but then, I would need some more!
> 
> Thanks a lot,
>         Simon
> --
> +-------------------------+----------------------------------+
> | Simon Lemieux           |         http://connect.to/666Mhz |
> | lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
> +-------------------------+----------------------------------+

Post a reply to this message

> i think the 'graphics gems' series covers all kinds of graphics
> including raytracing.

And where can I find that?

Thanks,
	Simon


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

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Simon Lemieux wrote:
> 
> > i think the 'graphics gems' series covers all kinds of graphics
> > including raytracing.
> 
> And where can I find that?

http://www.acm.org/tog/GraphicsGems/

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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A friend just sent me a reviewer's copy of a book titled "Realistic Raytracing" by
Peter Shirley.  I am at best a novice POV user and know nothing of coding a
raytracer, but I read a few chapters of this book and I would say it should be worth
a look for you.  It lays out what you need to do in a very down-to-earth way,
step-by-step, or so it seems to my mostly uninformed eye.
/j

Simon Lemieux wrote:

> Hi,
>         I've played with povray for a long time now and I realize that it's not
> optimized for the kind of render I'm doing...  I mean povray takes forever to
> parse a few millions of cylinders that have the same texture...  Yes, I know a
> few Millions is a very huge number and should simply require more memory, but
> povray crashed after filling my 128M of RAM and my 256M of swap...
>
> Here I go...  I would like to make my own raytracer, not based on any point of
> povray...  and optimize it for my own work...  but I never tried to make one and
> I'm entering college for the first year this september,  what I was looking for
> by posting this news is a list of books I should read in order to have a better
> knowledge of this subject...  I prefer book over URL-documentation (unless
> there's a .ps or .pdf i can print...)...
>
> I already got a hand on Computer Graphics: Principles and Practice (Foley,
> vanDam), but then, I would need some more!
>
> Thanks a lot,
>         Simon
> --
> +-------------------------+----------------------------------+
> | Simon Lemieux           |         http://connect.to/666Mhz |
> | lem### [at] yahoocom  | POV-Ray, OpenGL, C++ and more... |
> +-------------------------+----------------------------------+

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ryan constantine wrote:
> 
> i think the 'graphics gems' series covers all kinds of graphics
> including raytracing.

I would agree (noting especially that Graphics Gems IV has an article on
line-cylinder intersection), and I'd add the following three books on
writing ray tracers:

Glassner, _An Introduction to Ray Tracing_
Wilt, _Object-Oriented Ray Tracing in C++_
Shirley, _Realistic Ray Tracing_

Also, since you're interested in textures:

Ebert et al., _Texturing and Modeling_

-Mark Gordon

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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.

-- 
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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In article <399CADE9.1D14841A@mailbag.com> , Mark Gordon 
<mtg### [at] mailbagcom>  wrote:

> I would agree (noting especially that Graphics Gems IV has an article on
> line-cylinder intersection), and I'd add the following three books on
> writing ray tracers:
>
> Glassner, _An Introduction to Ray Tracing_
> Wilt, _Object-Oriented Ray Tracing in C++_
> Shirley, _Realistic Ray Tracing_
>
> Also, since you're interested in textures:
>
> Ebert et al., _Texturing and Modeling_

Not to mention the "Suggested Reading" section in the POV-Ray
documentation... :-)


       Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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>   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 wrote:

>         My scene has no light, nothing else than a few millions of cylinders all the
> same texture.

(snip)

>         I am very interested in Povray, but sometimes I would need a specific
tool...

Given that your scene has no light, I'm not convinced that the tool you
need is a ray tracer.  If you were doing ten million shiny cylinders on
a checkerboard, maybe.  I might suggest considering a different
algorithm if you're not going to be doing anything fancy with lighting.

-Mark Gordon

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