Trigger

A trigger is a zero-sized node that has no visual representation and fires callbacks when:

• It is enabled/disabled (an enabled callback function is called).
• Its transformation is changed (a position callback function is called).

A Node Trigger is usually added as a child node to another node, so that the callbacks will be fired on the parent node enabling/disabling or transforming.

The Node Trigger can work with procedurally created World Clutter objects.

The Node Trigger can be used, for example, to play a sound of thunder when a lightning flashes: when the lightning node is enabled, the enabled callback function that plays a sound is called.

See also#

To add a new Node Trigger via UnigineEditor do the following:

1. Run UnigineEditor.
2. On the Menu bar, click Create -> Logic -> Node Trigger.

   

3. Place the Node Trigger in the world.
   
4. Add the Node Trigger as a child to a node for which callbacks should be fired: select the Node Trigger in the World Nodes Hierarchy window and drag it inside the required node.
   

To edit the Node Trigger, select it and go to the Node tab of the Parameters window.

To add enabled/disabled or position callback, write a callback function that receives at least 1 argument of the NodeTrigger type. Then use use addEnabledCallback() / addPositionCallback() to specify the function to be called. See other methods of editing Node Trigger callbacks here.

// add the enabled and position callbacks
nodeTrigger->addEnabledCallback(MakeCallback(this, &enabled_callback));
nodeTrigger->addPositionCallback(MakeCallback(this, &position_callback));

// add the enabled and position callbacks
nodeTrigger.AddEnabledCallback(enabled_callback);
nodeTrigger.AddPositionCallback(position_callback);