RE: [Algorithms] very high poly collision

[Tom N. <t.n...@vr...>]

> An advantage of OBB trees lies in the ability to
> programmatically fit them
> to geometry.  I'm not sure how you would write code that
> decided wheter a
> sphere, a cone, or an OBB is the better fit for part of a=
 mesh.

Quite right - this is one of the issues that I'm still struggling=
 with. One
idea that crossed my mind is to just build a tree of spheres=
 until the
number of polygons inside a sphere drops below a certain=
 threshold, and then
fit an OBB tree around those polygons.

I suppose some human intervention will always be necessary to get=
 good
results with this, though, especially if you want to mix more=
 than just
spheres and OBBs (e.g. cones and AABBs as well). A lot also=
 depends on how
your meshes are structured. If they're just polygon soup, this=
 approach
probably won't work very well, but it might do a bit better if=
 your meshes
are hierarchical to begin with.

- Tom