Thomas de Groot wrote:
> "stbenge" <myu### [at] hotmailcom> schreef in bericht 
> news:4c6acef8@news.povray.org...
>> I haven't tried Edouard's code yet, though I did search for some examples 
>> with Google's image search. The repetition is often very noticeable, as 
>> seen in the following images:
>>
>> http://www.puc-rio.br/marco.ind/imagens/halton_2d.gif
>> http://www.mathworks.com/matlabcentral/fx_files/17457/1/halton.jpg
>> http://www.blitzcode.net/images/projects/project_150_big.png
>>
>> The first and second examples repeat completely in one diagonal direction, 
>> and partially in another. The third is a bit harder to tell, but there is 
>> definitely some partial repetition present, even with the low number of 
>> points.
> 
> What do you think of the image rendered with Edouard's code, I uploaded to 
> p.b.i.?

I think that gaining some speed isn't worth the result. Like the other 
Halton sequences I have seen, the one you rendered shows a lot of 
repetition. And there are numerous instances in which the particles line 
up unnaturally. In fact, they are so numerous that they cannot be 
misconstrued as mere coincidences.

Have you tried placing ten times the number of particles that you used 
for that example? With smaller particle sizes? Is so, do the particles 
ever overlap? I suppose that if you can use more particles, then the 
periodicity may not be much of an issue, but the diagonal alignment 
problem will still be present.

I've been thinking about just making some scripts to generate spaced 
point sets with min/max particle sizes, pigment-based distribution, and 
maybe even some macros for accessing the points.

Sam

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