Event Example

Here is a short example of using the Collision Handler Events:

from direct.showbase.ShowBase import ShowBase from direct.showbase.DirectObject import DirectObject from direct.interval.IntervalGlobal import Sequence, Func, Wait from panda3d.core import CollisionTraverser, CollisionHandlerEvent from panda3d.core import CollisionNode, CollisionSphere   class World(DirectObject):   def __init__(self):  # Initialize the traverser.  base.cTrav = CollisionTraverser()   # Initialize the handler.  self.collHandEvent = CollisionHandlerEvent()  self.collHandEvent.addInPattern('into-%in')  self.collHandEvent.addOutPattern('outof-%in')   # Make a variable to store the unique collision string count.  self.collCount = 0   # Load a model. Reparent it to the camera so we can move it.  s = base.loader.loadModel('smiley')  s.reparentTo(base.camera)  s.setPos(0, 25, 0)   # Setup a collision solid for this model.  sColl = self.initCollisionSphere(s, True)   # Add this object to the traverser.  base.cTrav.addCollider(sColl[0], self.collHandEvent)   # Accept the events sent by the collisions.  self.accept('into-' + sColl[1], self.collide3)  self.accept('outof-' + sColl[1], self.collide4)  print(sColl[1])   # Load another model.  t = base.loader.loadModel('smiley')  t.reparentTo(base.render)  t.setPos(5, 25, 0)   # Setup a collision solid for this model.  tColl = self.initCollisionSphere(t, True)   # Add this object to the traverser.  base.cTrav.addCollider(tColl[0], self.collHandEvent)   # Accept the events sent by the collisions.  self.accept('into-' + tColl[1], self.collide)  self.accept('outof-' + tColl[1], self.collide2)  print(tColl[1])   print("WERT")   def collide(self, collEntry):  print("WERT: object has collided into another object")  collParent = collEntry.getFromNodePath().getParent()  Sequence(  Func(collParent.setColor, (1, 0, 0, 1)),  Wait(0.2),  Func(collParent.setColor, (0, 1, 0, 1)),  Wait(0.2),  Func(collParent.setColor, (1, 1, 1, 1)),  ).start()   def collide2(self, collEntry):  print("WERT.: object is no longer colliding with another object")   def collide3(self, collEntry):  print("WERT2: object has collided into another object")   def collide4(self, collEntry):  print("WERT2: object is no longer colliding with another object")   def initCollisionSphere(self, obj, show=False):  # Get the size of the object for the collision sphere.  bounds = obj.getChild(0).getBounds()  center = bounds.getCenter()  radius = bounds.getRadius() * 1.1   # Create a collision sphere and name it something understandable.  collSphereStr = 'CollisionHull{0}_{1}'.format(self.collCount, obj.name)  self.collCount += 1  cNode = CollisionNode(collSphereStr)  cNode.addSolid(CollisionSphere(center, radius))   cNodepath = obj.attachNewNode(cNode)  if show:  cNodepath.show()   # Return a tuple with the collision node and its corresponding string so  # that the bitmask can be set.  return (cNodepath, collSphereStr)   base = ShowBase() # Run the world. Move around with the mouse to create collisions. w = World() base.run()