I've got a few questions about ghosts, they're just not documented!
When does a ghost clear it's cache? Is it every frame? Every step? Or do I clear it when I'm checking it's collisions?
What are the methods convexSweepTest and rayTest for?
How do I get the cache from a btGhostObject? btPairCachingGhostObject is covered but I haven't seen any samples of btGhostObject in use.
questions on ghosts
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theyesfish
- Posts: 10
- Joined: Sat Apr 11, 2009 7:12 pm
Re: questions on ghosts
Replying to my own topic, lol...
Found the method to get object data from a regular btGhostObject:
for(int t = 0; t < ghost->getNumOverlappingObjects(); t++)
{
btCollisionObject* o = ghost->getOverlappingObject(t);
}
but it only returns the data for the AABB collisions, so it's kind of useless. I guess it could be used for AABB detection zones?
The cache is cleared at the start of each substep (at least I think so).
Still don't know what convexSweepTest and rayTest do.
Found the method to get object data from a regular btGhostObject:
for(int t = 0; t < ghost->getNumOverlappingObjects(); t++)
{
btCollisionObject* o = ghost->getOverlappingObject(t);
}
but it only returns the data for the AABB collisions, so it's kind of useless. I guess it could be used for AABB detection zones?
The cache is cleared at the start of each substep (at least I think so).
Still don't know what convexSweepTest and rayTest do.
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pico
- Posts: 229
- Joined: Sun Sep 30, 2007 7:58 am
Re: questions on ghosts
Hi,
the sweep tests test a collisionShape with the objects within the ghostObject. So you save asking the broadphase for collisions. This is pretty nice for character controllers.
the sweep tests test a collisionShape with the objects within the ghostObject. So you save asking the broadphase for collisions. This is pretty nice for character controllers.