[Yafray-devel] Re: Re: Re: About supersampling

[Guillermo S. Romero / Familia Romero]

address@hidden (2002-12-31 at 2044.42 +0100):
> Well, a solution for this looks very complicated. Fell free to try or
> suggest anything.

I did not said it was easy, and it was more a question than an
affirmation. I will think about it a bit more, first idea is the
typical sample at the corners, and if needed divide in four subpixels
(adds 5 new sample points per parent square), and so on. :]

Example with three levels, the big differences are in the top left of
this pixel, so it is where the third level is used, while the other
three subsquares do not require more samples:

1 3 2 . 1    1, 2 & 3 are samples, showing the level they are
3 3 3 . .    . means point that could be sample too, but is not sampled
2 3 2 . 2
. . . . .
1 . 2 . 1

This requires 1+x+y samples for an image, even if no oversampling is
needed, and tries to focus in changing areas. It can be combined with
jittering, to increase niceness. IIRC this is what POVRay does in one
of the antialiasing modes. Dunno at this moment if there are better
ways (for raytracing). And do not ask me how to do it with threads,
I will be happy with effective code for the basic part. :]

GSR