octree resolution, and rendertime ...

Hi all,

I read this http://www.blender.org/development/release-logs/blender-233/render-engine-features/

On the octree resolution setting.

First I tweaked with this parameter down and saw it reduces alot the render time. But with another scene it increases the rendertime.
Does it depend on number of objects in the scene, the number of faces in the scene, or simply the world size in blender units?

I think it depends on how many ray traceable objects are there in your scene. If you do not include those objects that do not need raytracing (by deselecting the ‘traceable’ flag from its material properties) it can speed things up.

It depends on both the size of the scene relative to the general size of the models, and also the amount of geometry in the scene. There are no general rules, and it’s bit of a pain to tweak especially on long renders since you pretty much have to do it by trial and error.

You can definitely speed things up by turning off traceable, but also keep in mind that if you have a bunch of traceable objects scattered aroud the periphery of the scene, with non-traceable objects in the middle, there may not be that much effect. It’s really tricky :frowning:

It would be nice if there was a default ‘Auto’ option that guessed the best fit (I bet the computer could do a better job at it than a user), or rather, than the Octree gets scrapped for something better and faster (kd-tree/bih) instead, but that a bit of a bigger project :slight_smile:

http://wiki.blender.org/index.php/BlenderDev/BIHTree :] Still early in the development stage. Looks like it might be good, though.

And stopped in the early development stage too… It would be very nice, but unfortunately Keir, the guy working on it, seemed to be having some problems with it and either gave up or put it on hold indefinitely and not-so-unfortunately has now decided to work on motion tracking.

Oh, did he?

…Well, nevermind, then. XP

It’s really strange to set up …
I made some tests with my scene, 128, the default, seem to be the best !
And is much faster than 64 or 512 …

can we have much more octree resolution
more than 512 ,such as 1024…2048…

in my test the more octree resolution the less render time