Tim Nikias v2.0 <tim### [at] gmxde> wrote:
> But what about recursion_limit? As I understand it,
> I do that all at once: shoot rays outward from first
> sample. The places where these hit will also shoot
> samples outward, and so, until recursion-limit is
> met.

  I think that the recursion can stop earlier for a certain sample ray
than recursion-limit if there are enough samples nearby, but basically
you are right.

> This way, I quickly get samples across the
> scene in the very beginning, which may then be
> accessed for the next samples. For this to work,
> the samples would have to get marked how deep
> they've already done their own recursion_limit... Tricky.

  Why do samples need to store their recursion level?
  *Rays* need to know their recursion level when they are traced, but that's
all. This is trivial and it's the exact same thing as the regular raytracing
process is doing anyways (for reflections and refractions).

> And finally, pretrace. As I understand it, pretrace is
> just another pass over the picture in order to check
> if enough samples are present at any given spot.

  AFAIK pretrace is simply a preprocessing step to get some initial
samples in the scene, thus speeding up the actual raytracing.

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