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Collider Question

Topics: Developer Forum, User Forum
Jan 15, 2009 at 11:12 PM
I have a question about the colliders:
Does the brute force collider do any checking to see if it should even collision test a pair of geometries, or is that what the other two colliders are for?
Jan 16, 2009 at 12:24 PM
We have 3 broad phase colliders:
  • Brute force
  • Sweep And Prune
  • Selective Sweep
All of them have the same purpose: To check if geometries are close to each other and create an Arbiter object if they are.
Their difference is the way they check for near by geometries. The brute force on check each of them against another. It brute forces every geometry.
Also, each of the broad phase colliders have some preliminary tests to make sure that it only collide geometries that can collide. Example: Static bodies are not checked against each other, so are geometries with different collisiongroups.

Whenever an Arbiter has been created, the narrow phase collider kicks in. It checks in a more detailed way if geometries collide. It does that by checking each geometry's distance grid against each other. It's very costly so that's why we speed it up by using the broadphase.

Hope that clears up things. If you have further questions, feel free to ask.
Jan 18, 2009 at 12:43 AM
Thanks for all of the information. That's what i wanted to know.