Create nParticle collision events

Use the Particle Collision Event Editor to create events that generate or kill particles when nParticles collide with other nParticle systems or Nucleus objects. 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.

Note:

When creating particle collision events, be aware of the following:

• The collisionGeometryIndex output attribute is not supported for nParticles collision events.
• 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 nParticle collision event

1. Select the nParticle object you want to use as the event source particle object.
2. In the FX menu set, select nParticles > Particle Collision Event Editor.
3. In the Particle Collision Event Editor, click Create Event.

   The new event appears in the Events panel.

4. (Optional) Type a name for your event in the Set event name field.
5. 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.
     Tip:

     Be aware that nParticles emitted from the target object can collide with other nParticles, causing collision events to execute prematurely. To avoid unwanted nParticle collisions, you can turn off the Collide attribute on the target object. You can also use the Collide Strength and Collide Strength Scale attributes to dampen or delay collisions on the target object. See nParticle Collisions attributes.

   • 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 nParticle object’s shape node or its transform node name .
6. (Optional) To create another collision event, click New Event.