Re: [Algorithms] Colliding against polygon soup

[Brian H. <bw...@wk...>]

At 09:46 AM 12/7/00 +0800, Conor Stokes wrote:
>OBB-Trees can apply to interiors rather well actually. Heightmaps are
>special cases anyway, and suited to quadtrees much better (they are a very
>2d collision problem.)

I dislike the assumption that a terrain = heightmap.  I'd like to use a 
generalized mesh to represent a terrain region, say something like you'd 
say in the old Dagoth Moor demo that shipped with the GeForce.  Overhangs, 
caves, etc.

So if you're building an interior with OBB-Trees, how do you do it?  I 
mean, not the technical stuff, I'm talking about the logical stuff -- do 
you end up building it as discrete pieces (column 0, dais, stairs, rail, 
etc.) or as a single monolithic mesh and there's some magic OBB-Tree 
creation algorithm I'm unaware of that automatically takes a mesh and 
decomposes it into sane OBBs?

>with the same entity. Eg, a sphere can collide with 2 triangles, and needs
>to be pushed back from both of them.

I'm having a hard time visualizing this...what's an example of this?  Do 
you mean the case where the sphere is going into a "V" and pushing off of 
one triangle forces it into the other?

Brian