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OBB-OBB or OBB-Capsule: Which is faster?

Posted: Wed Apr 22, 2009 3:11 am
by SomeCallMeTim
Which is the faster collision code in the Toolbox.areObjectsCollidingMPR method: OBB-OBB or OBB-Capsule?

I'm guessing OBB-Capsule, because Capsule is a simpler shape?

Re: OBB-OBB or OBB-Capsule: Which is faster?

Posted: Wed Apr 22, 2009 9:32 am
by Norbo
The best way to find out would be to test your specific scenario, but they should be comparable. The algorithm doesn't do anything remarkably different for different types of shapes, but some contours can take longer to converge. MPR tends to work pretty well with both traditional polytope style objects and curved surfaces (GJK can take a bit longer to converge on curved surfaces than MPR, I believe).

There's a special case box-box test in there too (areBoxesColliding) which would be another fast option.

Re: OBB-OBB or OBB-Capsule: Which is faster?

Posted: Thu Apr 23, 2009 3:11 am
by SomeCallMeTim
Interesting.

One more question:

Is Bepu Physics based on a specific physics text or paper? It is based on some pre-existing code?

I'm just curious because I really like it, and am having good luck with it so far.

Maybe you are not disclosing this information. I would understand that.

Thanks,
Tim

Re: OBB-OBB or OBB-Capsule: Which is faster?

Posted: Thu Apr 23, 2009 5:04 am
by Norbo
The engine isn't based on any single resource; it basically evolved over time with independent work and varied research. I've learned quite a few valuable concepts from resources/information put out there by people like David Baraff, Erwin Coumans, Erin Catto, Gino van den Bergen, Christer Ericson, Gary Snethen, and a bunch of others. If any of them see this, thanks :D

Re: OBB-OBB or OBB-Capsule: Which is faster?

Posted: Fri Apr 24, 2009 2:18 am
by SomeCallMeTim
Ok, thanks! I have heard of at least one of those names.

I can tell that a lot of work has been put into Bepu.