POV-Ray : Newsgroups : povray.binaries.images : Motecarlo path tracing with MegaPov 1.2.1 : Re: Motecarlo path tracing with MegaPov 1.2.1 Server Time
5 Nov 2024 00:27:14 EST (-0500)
  Re: Motecarlo path tracing with MegaPov 1.2.1  
From: fidos
Date: 3 Feb 2008 03:05:00
Message: <web.47a5755bdcec6a9fce311500@news.povray.org>
Tim Nikias <JUS### [at] gmxnetWARE> wrote:
> fidos wrote:
> So you simply shoot rays in random directions once you hit a surface to
> generate the lighting?
Yes
>
> Interesting idea, what are you planning in terms of optimisation?
A good optimisation for a quicher noise reduction is to sample the lights after
projection on the hemisphere surrounding a hit point. An other one is to shoot
in priority on pixel with noise.
> And how is your current technique working? Are you shooting several light
> rays per pixel, or are just reiterating the entire scene again and again
> and add up all the results?
There is no light ray. At each object surface hit, I shoot n x n ray to sample
the hemisphere. When a ray hit a emmisive surface, I return the emmisive value.
The process is recursive and is stopped by the maximum allowed recursion depth
is reached (for the moment the max_trace_level). So only ray that hits a light
source contribute to the pixel color (it is the reason for such noise and so
long rendering time of this technique). The scene is rederered again and again
and the pixel values are accumulated. It is slowly converging, starting with a
very noisy picture.
>
> Regards,
> Tim


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