Apache wrote:
> 
> The set that POV-Ray uses currently doesn't look like that either. (see my
> post, pbi "Re: >1600 radiosity samples: right costheta distribution?").

You are obviously doing something wrong, i just rendered it and it look
totally different here (it looks indeed uniform although not extremly high
quality).

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 31 Dec. 2002 _____./\/^>_*_<^\/\.______

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I'm nuts .......    I rerendered it and it turned out to be some perspective
distortion :-)

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"Apache" <apa### [at] yahoocom> wrote in
news:3e16ad01$1@news.povray.org 

[...]

Maybe just make a scene that needs >1600 samples, build i.e. 5000 samples 
array, re-compile POV and make few renders involwing old and new 
distribution

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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"Nathan Kopp" <pov### [at] nkoppmailshellcom> wrote in
news:3e1714cf$1@news.povray.org 

> If it realy is O(n), which would be great, couldn't you simply
> generate an appropriate distribution each time, removing the need to
> order them.  If the algorithm produces evenly spaced samples for small
> counts, this would also ensure that small sample counts look their
> best. 

Why not generate array of arrays ?
array for count=3, count=4, count=5 etc... ?

taht would be much faster then generating in real-time, and will not use to 
much memory


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Rafal 'Raf256' Maj wrote:
> Why not generate array of arrays ?
> array for count=3, count=4, count=5 etc... ?
>
> taht would be much faster then generating in real-time, and will not use
to
> much memory

Uh, it won't? Just the tables for up to 1600 samples would require 3.7 MB in
packed format, and we want to go well beyond that!

Anders

--
#macro E(D)(#if(D<2)D#else#declare I=I+1;mod(pow(.5mod(I 6))*asc(substr(
"X0(1X([\\&Q@TV'YDGU`3F(-V[6Y4aL4XFUTD#N#F8\\A+F1BFO4`#bJN61EM8PFSbFA?C"
I/6 1))2)<1#end)#end#macro R(D,I,T,X,Y)#if(E(D))R(D-1I,T,Y/2X)R(D-1I,T+Y
/2Y/2X)#else box{T T+X+Y pigment{rgb E(2)*9}}#end#end R(10,5z*3-1v*2u*2)

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And that's exactly what I'm planning on.

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That's exactly what came to my mind, too.

I tweaked my old sunflower-testscene to generate the points on
a hemisphere like Mael described in his post.

I quite like how it came out. It looks evenly distributed when viewed
from above with orthographic view and it scales good with increasing
number of points.

I posted the anims in p.b.a
comments are welcome,

Thies

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My box is currently calculating a set of 6400 samples. It seems it will take
quite some time, but whenever it's finished, I'll let you know.

The ordering is very good, so with very low samples the distribution is very
good. If the count is set to 6400, the distribution is equal to the golden
ration distribution. (See Thies Heidecke's post in this conversation.)


Regards,
Apache

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Apache wrote:
> 
> My box is currently calculating a set of 6400 samples. It seems it will take
> quite some time, but whenever it's finished, I'll let you know.
> 
> The ordering is very good, so with very low samples the distribution is very
> good. If the count is set to 6400, the distribution is equal to the golden
> ration distribution. (See Thies Heidecke's post in this conversation.)

You should note that this is a regular distribution, therefore will be
likely to generate regular artefacts under certain circumstances.  Using
regular distributions has been tried before, see for example:

http://perso.wanadoo.fr/albedo/patchedpov.html

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 31 Dec. 2002 _____./\/^>_*_<^\/\.______

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I found out the distribution isn't as good as I thought. I think the problem
is in the ordering, which is more complicated than I had expected  ;-)

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