Can anyone suggest how to save a photon map as a
separate color image without any other lighting effects?
I have a surface which needs to be diffuse and white for
other reasons but this obscures the caustics.  I thought
there might be a way to open a saved photon map
as an image in Photoshop or- ??

Any advice much appreciated.

Thanks,

Bo Gehring

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"louis gehring" <bog### [at] verizonnet> wrote in message
news:402b9a5f$1@news.povray.org...
> Can anyone suggest how to save a photon map as a
> separate color image without any other lighting effects?
> I have a surface which needs to be diffuse and white for
> other reasons but this obscures the caustics.  I thought
> there might be a way to open a saved photon map
> as an image in Photoshop or- ??

No, not that I've ever heard of anyway. Only thing you might be able to do
is rerender with the loaded photon map and comment out any lights to see it
better. Might look okay then, but I'm not 100% certain.

Bob H.

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louis gehring wrote:
> Can anyone suggest how to save a photon map as a
> separate color image without any other lighting effects?
> I have a surface which needs to be diffuse and white for
> other reasons but this obscures the caustics.  I thought
> there might be a way to open a saved photon map
> as an image in Photoshop or- ??

A photon map is a 3d data structure, there is no way to save it as an 
image file.  If you want to get a render of the scene with only photon 
based illumination you can try to render without light sources and a 
loaded photon map as Bob suggested.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 11 Jan. 2004 _____./\/^>_*_<^\/\.______

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That worked.  Thanks!

Bo Gehring


"Hughes, B." <omn### [at] charternet> wrote in message
news:402ba10e$1@news.povray.org...
> "louis gehring" <bog### [at] verizonnet> wrote in message
> news:402b9a5f$1@news.povray.org...
> > Can anyone suggest how to save a photon map as a
> > separate color image without any other lighting effects?
> > I have a surface which needs to be diffuse and white for
> > other reasons but this obscures the caustics.  I thought
> > there might be a way to open a saved photon map
> > as an image in Photoshop or- ??
>
> No, not that I've ever heard of anyway. Only thing you might be able to do
> is rerender with the loaded photon map and comment out any lights to see
it
> better. Might look okay then, but I'm not 100% certain.
>
> Bob H.
>
>

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Christoph Hormann <chr### [at] gmxde> wrote:
> A photon map is a 3d data structure, there is no way to save it as an 
> image file.

  I think he is confusing photon maps with lightmaps (common rendering
technique for fast precalculated lighting).

  Theoretically you can certainly create lightmaps *from* photon maps, but
unless the renderer you are using supports lightmaps they will not be of
any help (POV-Ray does not support them because it would require UV-mapping
for all objects; lightmaps are most useful in scanline rendering).

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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in news:m8k### [at] tritonimagicode Christoph Hormann wrote:

> A photon map is a 3d data structure,

Not related to the thread, but would this mean that the datastructure 
could be converted in a density_file (df3)?

Ingo

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ingo wrote:
>>A photon map is a 3d data structure,
> 
> Not related to the thread, but would this mean that the datastructure 
> could be converted in a density_file (df3)?

To get usable data from this the density file would need an extreme 
resolution (and therefore file size).  And most of it would contain no 
data at all, only those grid positions where one or more photons are 
located.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 11 Jan. 2004 _____./\/^>_*_<^\/\.______

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In article <Xns948DB6C063518seed7@news.povray.org>,
 ingo <ing### [at] tagpovrayorg> wrote:

> > A photon map is a 3d data structure,
> 
> Not related to the thread, but would this mean that the datastructure 
> could be converted in a density_file (df3)?

Not as a DF3 file. DF3's store uncompressed, filled voxel data. An 8x8x8 
DF3 contains 512 voxels, each at a specific point in an 8x8x8 3D 
lattice. Technically you could create a voxel field from the photon 
data, but you wouldn't be able to store it...it'd be too big at any 
reasonable resolution, or blurred out at too low a resolution to be of 
any use. A 256x256x256 resolution voxel field would consume 16MB at one 
byte per voxel. 1024x1024x1024 with 24-bit RGB? 3GB. And in a field 10 
units on a side, that's a distance of just under 0.01 between photons.

Now, I'm working on an extended density format that allows sparse data, 
storing the location and value of each point rather than a value for 
every possible point. The files would be big, and there would be loss in 
location precision due to the use of integer coordinates, but it would 
be far more practical. Unfortunately, there currently are no programs 
capable of reading or writing this format, and the format itself isn't 
fully defined...I'll be starting a thread in *.programming on the 
subject soon.

-- 
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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