In article <c56tkq$mtt$1@chho.imagico.de>,
 Christoph Hormann <chr### [at] gmxde> wrote:

> That's how you do it with path tracing - noisy images are usually the 
> result unless you use really lot of samples.

The second path tracing method uses the same choices for every pixel of 
a pass, removing the noisiness. However, that means the entire image is 
equally inaccurate if you use too few samples. (or get really unlucky)

I've also had good results with using single-path tracing once the trace 
level reaches a certain depth. Splitting for the first 3 levels and then 
following single paths seems to give good results with few samples, and 
trimming out enough of the deeper rays to give a good speedup.


> You mean 64 passes together 5 minutes? 

Yes.


> And how do you combine them?

A simple average. Each pass is traced at a slight offset, with the 
result of the ray origins covering the pixels.


> The problem also is you usually don't have only reflection and 
> refraction but also a diffuse part.

That's always computed, no matter what. I could make it a third "path", 
but I don't think the results would be very good. 


> > I've posted three images in povray.binaries.images demonstrating the 
> > traditional method and the two new methods.
> > 
> 
> Were not viewable here.

Try the new posts.

-- 
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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