Panda Bullet

Hovis · August 1, 2012, 9:18pm

I have spent a stupidly long time trying to figure out how to get collision events from bullet.

I found this on page 9 of this thread:

enn0x:

enn0x:

@Nox_firegalaxy

Nox_firegalaxy wrote:
Hi, am I blind or is there no way to get an event if two objects collided? Im used to the ODE setCollisionEvent but to the best of my knowledge i would have to call getOverlappingNodes on ghosts and contactTest for rigid/dynamics. Is that correct? Is not there a way to get an event per collision if a doPhysics or a informAboutCollisions is called?

There is, but it is currently disabled. However, the API for this is still present (body.noftiyCollisions, then accept the “bullet-contact-added” etc. events).

I should mention how to enable this feature. But I think this is not exactly what you are looking for. A event is created each time a contact point is created.
# enable contact events
from pandac.PandaModules import loadPrcFileData
loadPrcFileData('', 'bullet-enable-contact-events true')

# activate generation of contact events for one body
body.notifyCollisions(True)

# listen for events
self.accept('bullet-contact-added', self.doAdded)
self.accept('bullet-contact-destroyed', self.doDestroyed)

# finally the event handlers
def doAdded(self, node1, node2):
  print 'added:', node1.getName(), node2.getName()

def doDestroyed(self, node1, node2):
  print 'destroyed:', node1.getName(), node2.getName()
Please keep in mind that:
1.) More than one contact point can be created for two bodies touching each other.
2.) Contact points can get created and removed again and again while the bodies “slide” against each other.

Is all of this still true?

If I’m understanding you correctly, I can turn on collision notification but I will get events published for each of your internally calculated contact points; potentially seeing many many notifications for each collision.

Getting some nice logical collision events would be super cool.

If you’re busy working on other features, how can I help make this happen? I’ve got a project I’m currently working on and I need this functionality, faking it in my python will be far too slow.