Create particle collision events

You can use the Particle Collision Event Editor to create events that occur when particles collide with geometry. Using a collision event, you can create new particle objects that emit into the scene or kill particles when they collide. You can create collision events for particle and nParticle objects.

NoteCollision events can only occur when particles from different particle or nParticle systems collide. Collision events can not occur when nParticles self-collide.

You can also execute a MEL script when particles or nParticles collide. The actions that occur after contact are called events. See Create a MEL procedure for collision events.

For more information about using nParticles with collision events, see nParticle collision events.

NoteWhen creating particle collision events using nParticles, be aware of the following:

The collisionGeometryIndex output attribute is not supported for nParticles collision events in Maya 2011.
nParticle collisions events pass the name of the Nucleus object that the nParticles are colliding with rather the geometry's name to the event callback.
The Nucleus ground plane cannot be the target of an nParticle collision event.

To create a particle or nParticle collision event

Select the particle or nParticle object you want to use as the event source particle object.
Depending on the source particle type, do one of the following:
- For a classic particle object, in the Dynamics menu set, select Particles > Particle Collision Events Editor.
- For an nParticle object, in the nDynamics menu set, select nParticles > Particle Collision Event Editor.
  The Particle Collision Event Editor appears.
Click Create Event.
The new event appears in the Events panel.
(Optional) Type a name for your event in the Set event name field.
Specify the frequency of the event by doing one of the following:
- Turn on All Collisions if you want the event to execute on each particle collision.
- Specify at which collision you want the event to execute by setting the Collision number.
Under Event type, specify the event settings by doing the following:
- Turn on either Emit or Split.
  When Emit is on, the source particle object continues to live after the collision event. The target particle age starts when the object is created.
  
  When Split is on, the source particle object dies after the collision event. The target particle inherits its age from the source particle.
- If you want to create a random number of target particles, turn on Random # particles. See Random # Particles.
- Specify the number of target particles you want to create for each particle collision by setting Num particles.
- Set the Spread for the target particles.
- Specify the Target particle by typing the name of an existing particle or nParticle object. You can use either the name of the particle object’s shape node (particleShape or nParticleShape), or its transform node name (particle or nParticle).
  If you do not specify a particle type, the target will be an nParticle object.
(Optional) To create another collision event, click New Event.