> I don't want to brag, but I think this is a breakthrough for radiosity:
>
> The attached images show a purely radiosity-lit scene, using
> pathologically small light emitters (three tiny spheres).
>
> Image #1 shows the familiar splotchy output even at the maximum sample
> ray count of 1600 and a nearest_count of 10, after a render time of 1
> minute 45 seconds on my Core i7 machine.
>
> Image #2 shows how this can be improved (not surprisingly) by using a
> count of 6400 instead, after having replaced the built-in sample
> sequence with a 160,000-element halton sequence, of which a subset of
> 6400 was picked for each sample in a round-robin fashion. Splotches are
> almost gone, but there's a caveat: Render time increased to 7 minutes 20
> seconds.
>
> Image #3 however shows even better quality with a rendering time of just
> 2 minutes 18 seconds. On the same machine. With virtually identical
> settings. So what's the deal here?
>
> The basic idea is pretty simple: Trace fewer radiosity sample rays if
> they only hit non-important objects :-)
>
> Of course we can't know in advance whether we will hit important or
> non-important objects; however, we /can/ decide to perform full
> computations only on a subset of rays hitting non-important objects
> (applying a factor to compensate for the discarded rays), so that at
> least we need to perform fewer texture computations - not to mention
> secondary rays for reflections or shadow computations.
>
> For image #3, 12,800 rays were shot per sample, but I guess only roughly
> 2-5% of them (i.e. about 256 - 640) were continued beyond the ray-object
> intersection tests.
>
>
> Hey, I like this!

Very good! Congratulation, you are welcome to brag about your work :)

The 3rd image seems the best to me. In the others, the area under the 
large spheres, especialy the red one, look to bright.


Alain

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