Behavior Tree

Component entity system is in preview release and is subject to change.

Use the Behavior Tree component to load and run a Modular Behavior Tree Node Reference for the attached entity.

Behavior Tree Component Properties

The Behavior Tree component has the following properties:

Behavior tree asset

Select an XML file that contains a behavior tree definition.

Enabled initially

When selected, the behavior tree is loaded and activated with the entity.

EBus Request Bus Interface

Use the following request functions with the event bus (EBus) interface, BehaviorTreeComponentRequestBus, to communicate with other components of your game.

For more information about using the EBus interface, see Working with the Event Bus (EBus) System.

StartBehaviorTree

Starts an inactive behavior tree associated with this entity.

Parameters

None

Return

None

Scriptable

Yes

StopBehaviorTree

Stops an active behavior tree associated with this entity.

Parameters

None

Return

None

Scriptable

Yes

GetVariableNameCrcs

Gets a list of all crc32s of the variable names.

Parameters

None

Return

AZStd::vector<AZ::Crc32>

Scriptable

Yes

GetVariableValue

Gets the value associated with a variable.

Parameters

AZ::Crc32 variableNameCrc

Return

bool

Scriptable

Yes

SetVariableValue

Sets the value associated with a variable.

Parameters

AZ::Crc32 variableNameCrc

bool newValue

Return

None

Scriptable

Yes

The following is an example of script using the Request Bus Interface.

local behaviortreescript =
{
    Properties =
    {
        Target = EntityId(),
    },
}
   
function behaviortreescript:OnActivate()
    BehaviorTreeComponentRequestBus.Event.StartBehaviorTree(self.entityId)
    BehaviorTreeComponentRequestBus.Event.SetVariableValue(self.entityId, Crc32("HasTarget"), self.Properties.Target:IsValid())
end
 
return behaviortreescript