Behavior Tree Nodes

Behavior Trees are very extensible meaning you can create own node types in your game project or use the ones from engine and plugins. Each node can define custom logic, contain properties and store runtime state (per-instance). This page contains a list of all in-built node types with their documentation.

Root

Root node of the behavior tree. Contains logic properties and definitions for the runtime. Created automatically for each Behavior Tree and cannot be removed.

Property	Description
Blackboard Type	Type of the blackboard data (structure or class). Spawned for each instance of the behavior. See knowledge docs to learn more.
Goal Types	List of types of the behavior goals (structure or class). See knowledge docs to learn more.
Update FPS	The target amount of the behavior logic updates per second.

Sequence

Sequence node updates all its children (from left to right) as long as they return success. If any child fails, the sequence is failed.

Selector

Selector node updates all its children (from left to right) until one of them succeeds. If all children fail, the selector fails.

Delay

Delay node that waits a specific amount of time while executed.

Property	Description
Wait Time	Time in seconds to wait when node gets activated. Unused if Wait Time Selector is used.
Random Deviation	Wait time randomization range to deviate original value.
Wait Time Selector	Wait time from behavior's knowledge (blackboard, goal or sensor). If set, overrides Wait Time but still uses Random Deviation.

Sub Tree

Sub-tree node runs a nested Behavior Tree within this tree.

Property	Description
Tree	Nested behavior tree to execute within this node.

Force Finish

Forces behavior execution end with a specific result (eg. force fail).

Property	Description
Result	Execution result.

Move To

Moves an actor to the specific target location. Uses pathfinding on navmesh.

Property	Description
Agent	The agent actor to move. If not set, uses Behavior's parent actor.
Movement Speed	The agent movement speed. Default value is 100 units/second.
Target	The target movement object.
Target Location	The target movement location.
Acceptable Radius	Threshold value between Agent and Target goal location for destination reach test.
Target Goal Update Tolerance	Threshold value for the Target actor location offset that will trigger re-pathing to find a new path.
Use Pathfinding	If checked, the movement will use navigation system pathfinding, otherwise direct motion to the target location will happen.
Use Partial Path	If checked, the movement will start even if there is no direct path to the target (only partial).
Use Target Goal Update	If checked, the target goal location will be updated while Target actor moves.