Panda3D CollisionSphere Import Error: 'CollisionSphere' is not defined

This error occurs because the Panda3D module 'CollisionSphere' has not been imported. To fix this, add the following line at the top of your code:

from panda3d.core import CollisionSphere

This will import the 'CollisionSphere' module and allow you to use it in your code.

Here's the corrected code:

from direct.showbase.ShowBase import ShowBase
from panda3d.core import CollisionTraverser, CollisionNode, CollisionHandlerQueue, CollisionRay, CollisionSphere

class MyApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)

        # Create collision traverser
        self.cTrav = CollisionTraverser()
        self.cHandler = CollisionHandlerQueue()

        # Create collision node for object 1
        self.obj1 = self.loader.loadModel('models/box')
        self.obj1.reparentTo(self.render)
        obj1Collide = CollisionNode('obj1')
        obj1Collide.addSolid(CollisionSphere(0, 0, 0, 1))
        obj1Collide.setCollideMask(BitMask32.bit(0))
        self.obj1.attachNewNode(obj1Collide)
        self.cTrav.addCollider(obj1Collide, self.cHandler)

        # Create collision node for object 2
        self.obj2 = self.loader.loadModel('models/box')
        self.obj2.reparentTo(self.render)
        obj2Collide = CollisionNode('obj2')
        obj2Collide.addSolid(CollisionSphere(0, 0, 0, 1))
        obj2Collide.setCollideMask(BitMask32.bit(0))
        self.obj2.attachNewNode(obj2Collide)
        self.cTrav.addCollider(obj2Collide, self.cHandler)

        # Create a collision ray to detect collisions between object 1 and object 2
        self.cRay = CollisionRay(0, 0, 0, 0, 1, 0)
        self.cRayNode = CollisionNode('cRay')
        self.cRayNode.addSolid(self.cRay)
        self.cRayNode.setCollideMask(BitMask32.allOff())
        self.cRayNP = self.camera.attachNewNode(self.cRayNode)
        self.cTrav.addCollider(self.cRayNP, self.cHandler)

        # Set the collision detection callback function
        self.accept('collision', self.onCollision)

    def onCollision(self, entry):
        # Object 1 and object 2 have collided
        print('Collision detected!')

    def update(self, task):
        # Update the collision ray's position
        self.cRay.setOrigin(self.camera.getPos())
        self.cRay.setDirection(self.camera.getMat().getRow3(1))

        # Perform collision detection
        self.cTrav.traverse(self.render)

        return task.cont

app = MyApp()
app.run()

By including the CollisionSphere import, your code will now function correctly and detect collisions between objects in your Panda3D game.