{{tag>dragonscript behavior}}
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[[:start|Start Page]] >> [[main|DragonScript Scripting Language]] >> [[dragengine:modules:dragonscript:abstractions|Abstraction Layers: How you want to build your Game]] >> [[dragengine:modules:dragonscript:behavior_elements|Behavior Elements]] >> **ECBehaviorVRHandPointedAt**
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  * [[behaviors_use_cases|Behaviors Explained: By Use-Case]]
  * [[behaviors_a_to_z|Behaviors Explained: From A to Z]]

====== ECBehaviorVRHandPointedAt ======

Behavior element behavior adding support to track if VR hands point at element.

This behavior tracks if hand controllers are pointing at the element. If hand controllers start pointing at the element they are added to the list and listeners are notified. If the hand controllers stop pointing at the element they are removed from the list and listeners are notified. The behavior itself is passive. It requires to be triggered by the hand controllers elements. The [[behavior_vrhandpointat|ECBehaviorVRHandPointAt]] behavior provides this functionality.

====== Instance Counts ======

This behavior can be used only once on an element.

====== Element Class Properties ======

Element class properties have the prefix ''vrHandPointedAt.'' .

This behavior defines no element class properties.

====== Events ======

===== handStartsPointingAt =====

Hand starts pointing at element.

===== handStopsPointingAt =====

Hand stops pointing at element.

====== Behavior Tree Actions ======

This behavior adds these behavior tree actions if behavior tree is present.

===== vrHandPointedAt.check =====

Check one or more vr hand pointed-at parameters. Action succeeds if all parameter value matches their respective vr hand pointed-at parameter otherwise action fails. This action is typically used as first action in a sequence to run the sequence only if a vr hand pointed-at parameter matches (or not).

^Parameter^Value^Description^
|count|integer|Count of vr hands pointing at element equals integer value|
|count.not|integer|Count of vr hands pointing at element does not equal integer value|
|count.less|integer|Count of vr hands pointing at element is less than integer value|
|count.greater|integer|Count of vr hands pointing at element is greater than integer value|
|player|''true'', ''false''|Player is pointing at element|
|wait| |If present action returns BTResult.running instead of BTResult.failed to wait until the checks are all fulfilled|

This is an example of using this action:
<code xml>
<sequence>
  <action name='vrHandPointedAt.check'>
    <parameter name='player'>true</parameter>
  </action>
  <!-- actions here run only if player is pointing at element -->
</sequence>
</code>

====== Behavior Tree Conditions ======

This behavior adds these behavior tree conditions if behavior tree is present.

===== vrHandPointedAt.check =====

Check one or more vr hand pointed-at parameters. Conditions returns true if all parameter value match their respective vr hand pointed-at parameter. This condition is typically used to run an action or sequence of actions as long as vr hand pointed-at conditions are true.

^Parameter^Value^Description^
|vrHandPointedAt.count|integer|Count of vr hands pointing at element equals integer value|
|vrHandPointedAt.count.not|integer|Count of vr hands pointing at element does not equal integer value|
|vrHandPointedAt.count.less|integer|Count of vr hands pointing at element is less than integer value|
|vrHandPointedAt.count.greater|integer|Count of vr hands pointing at element is greater than integer value|
|vrHandPointedAt.player|''true'', ''false''|Player is pointing at element|

This is an example of using this condition:
<code xml>
<action name='myAction' id='doing something'>
  <parameter name='vrHandPointedAt.player'>true</parameter>
  <condition>vrHandPointedAt.check</condition>
</action>
</code>

====== State Machine Actions ======

Same as [[#behavior_tree_actions|Behavior Tree Actions]].

====== State Machine Conditions ======

Same as [[#behavior_tree_conditions|Behavior Tree Conditions]].

====== State Machine Events ======

This behavior sends these state machine events. If behavior has non-empty identifier replace ''occupier'' with ''occupier(id)''.

===== vrHandPointedAt.start =====

Hand starts pointing at element.

===== vrHandPointedAt.stop =====

Hand stops pointing at element.

====== Required Behaviors ======

This behavior does not required other behaviors to be present.

====== Optional Behaviors ======

  * [[behavior_behaviortree|ECBehaviorBehaviorTree]]: Add actions and conditions for behavior trees to use.
  * [[behavior_statemachine|ECBehaviorStateMachine]]: Add actions and conditions for state machine to use and events to send to the state machine.

====== Persistency ======

This behavior does support element class to be persistable (setPersistable).

====== API Documentation ======

#@LinkApiDocDEDS2_HTML~classDragengine_1_1Scenery_1_1ECBehaviorVRHandPointedAt.html,ECBehaviorVRHandPointedAt~@#.

Since DragonScript Module Version ''1.7''

====== Use Cases ======

  * Show outline and interact prompts if player points at object.
  * For NPCs to react to player (or other actors) pointing at them (for example looking back at player).
  * Show target information if player aims at objects.

====== Element Class Example ======

<code>
class ExampleElementClass extends BehaviorElementClass
   public var ECBehaviorVRHandPointedAt vrHandPointedAt
   
   public func new() super("ExampleElement")
     // Add pointed at behavior. By itself this does nothing yet. Add listeners to the
     // behavior to react to pointing-at changes. This is typically done by other
     // behaviors to provide their functionality
     vrHandPointedAt = ECBehaviorVRHandPointedAt.new(this)
   end
end
</code>

====== Behavior Factory ======

Using element class supporting adding behaviors the behavior can be added like this:
<code xml>
<?xml version='1.0' encoding='UTF-8'?>
<elementClass name='MyClass' class='GenericBehaviorElement'>
  <behavior type='ECBehaviorVRHandPointedAt'>
    <!-- optional: add behavior trees. default adds all behavior trees. -->
    <list name='behaviorTrees'>
      <string/> <!-- add behavior with empty identifier -->
      <string>default</string> <!-- add behavior with 'default' identifier -->
    </list>
    
    <!-- optional: add state machines. default adds all state machines. -->
    <list name='stateMachines'>
      <string/> <!-- add behavior with empty identifier -->
      <string>default</string> <!-- add behavior with 'default' identifier -->
    </list>
    
    <!-- set element properties. omit property prefix if used inside behavior tag -->
    <string name='.name'>value</string>
  </behavior>
</elementClass>
</code>

====== Live Examples ======

  * [[https://github.com/LordOfDragons/deexamples|DEExamples Repository]]