Collision Callbacks

[jamesm6162]

Hi

I am running into a problem where it seems the collision callbacks are only called the first time that the collision happens between two bodies. If they are still colliding in the next update, then the callbacks are not called again.

I basically need to detect when two bodies "stop" colliding. So in my application I store the contacts in the callbacks and I clear them before every update. But right now this doesn't work as the callbacks are never called again after the first time for two bodies resting on each other for example.

Is there any other way how I can detect when the are colliding or not?

Thanks

James

[JoeJ]

You can iterate over contacts from a body to find all other bodies touching it:

Code: Select all

for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint(body); joint;
  joint = NewtonBodyGetNextContactJoint(body, joint))
{
 NewtonBody* b0 = NewtonJointGetBody0(joint);
 NewtonBody* c1 = NewtonJointGetBody1(joint);
 NewtonBody* otherBody = (b0==body ? b1 : b0);
}


But i don't know if there is a faster way.

[Julio Jerez]

you can look at class CustomTriggerManager and implement one of your own or use that one as an example of how to do what you described.

If a pair is sleeping the call back is no called. this is how the engine manage to get performance.
if you are using version 3.13 and up, you can look at function
void CustomTriggerManager::UpdateTrigger (CustomTriggerController* const controller)

as Joe say you can get the object, and iterate over the contact joints, the you can check if the joint is active, NewtonJointIsActive in order to see if the object are colliding.
is it common for tow objects to have a joint and not be colliding,