[Soc-2009-dev] Raytrace api

[Matt Ebb]

On Sat, May 23, 2009 at 3:30 AM, André Pinto <andresusanopinto at gmail.com> wrote:
> Hi,
>
> I probably wont be able to be online this sunday meeting.
> Anyway my SoC plans for this first week are:
>
> ===comming week===
>     *find the bug that makes some black dots.. before I only changed the API
> but it seems some bugs appeared.. I would like to have those sorted out
> before continuing. I already spend some time trying. but its kinda hard to
> debug it.

What are the black dots? I don't know if it helps or not, or even if
it's the same problem, but i've seen black dots/lines when rendering
volumetrics, and I *think* its an issue in the raytrace code. When
I've had these artifacts, I tried a whole bunch of things to try and
debug - changing the octree size changed the appearance of the dots,
triangulating my mesh helps to clean it up, and poking around in the
code adding a large-ish offset to the ray start location (0.1 or
something) helped too. From memory it happens when the ray fails to
find an intersection, even though it's just being cast along the view
vector with geometry behind. I wasn't able to figure out anything much
more than that.

Anyway, this may well be a problem in my code, or it may not be what
you're experiencing. If it is the same thing though, it shows its not
just in your code :)

I think this is an example of the problem here, too:
http://blenderartists.org/forum/showpost.php?p=1358587&postcount=651

cheers

Matt