Built-in Node Library

The omni.behavior.tree.core extension provides the built-in node library. These types are always available when the behavior tree system is enabled.

Composite Nodes

Composite nodes control the execution flow of their children.

Type	Description	Ports
Sequence	Ticks children in order; fails on first failure (AND gate).	(none)
Selector	Ticks children in order; succeeds on first success (OR gate).	shuffle · bool · default false — randomize child order each reset
Parallel	Ticks all children concurrently each tick. Completes when either threshold is reached.	success_count · int · default -1 (all children must succeed) failure_count · int · default 1

Action Nodes

Action nodes are leaf nodes that perform work and return a status.

Type	Description	Ports
Wait	Returns RUNNING for a duration, then SUCCESS.	duration · float · default 1.0
SetBlackboard	Writes a value to a blackboard slot. The slot port is pointer-style — a BlackboardRef carrying the (blackboard, key) pair to write to.	slot · BlackboardRef value · any type · optional
LogMessage	Logs a message and returns SUCCESS.	message · string
DispatchEvent	Fires a named carb event.	event_name · string payload_key · string · default "" blackboard_key · string · default ""
PushQueue	Appends an item to a FIFO queue stored at a blackboard slot. unique=true skips the push when the item is already present.	queue · BlackboardRef · pointer-style slot reference item · any type unique · bool · default false

Modifier Types

Modifiers attach to any node and wrap its execution. They support Abort Mode for reactive behavior (see User Guide for details on abort modes).

Type	Description	Input Ports	Output Ports
Repeat	Repeats child N times (counts completions).	count · int · default 0 (infinite) break_on_failure · bool · default false
Retry	Re-ticks child on failure.	max_retries · int · default 0 (infinite) reset_on_success · bool · default true
InvertStatus	Inverts child’s success/failure. RUNNING passes through.
ForceStatus	Returns configured status when child finishes.	status · string · default "success" Choices: success, failure
Delay	Waits before ticking child.	duration · float · default 1.0
Timeout	Fails if child doesn’t finish in time.	duration · float · default 1.0
Cooldown	Ticks child, then waits before completing.	duration · float · default 1.0
CheckBlackboard	Checks a blackboard entry against a condition. Uses on_check_condition for abort mode integration.	key · string query · string · default "IsSet" Choices: IsSet, IsNotSet, Equals, NotEquals compare_value · string	value · any
CheckEvent	Returns RUNNING until a carb event fires, then SUCCESS.	event_name · string payload_key · string · default "" blackboard_key · string · default "" timeout · float · default 0.0 (wait indefinitely)
RandomUniformFloat	Samples a random float in [min, max), cached until reset.	min · float · default 0.0 max · float · default 1.0 seed · int · default 0 (negative = non-deterministic)	value · float
RandomUniformInt	Samples a random integer in [min, max], cached until reset.	min · int · default 0 max · int · default 100 seed · int · default 0 (negative = non-deterministic)	value · int
RandomChoice	Picks a random element from an array.	choices · array seed · int · default 0 (negative = non-deterministic)	value · any
PopQueue	Atomically pops the head of a FIFO queue, binds it to the item output, and ticks the target. If the queue is empty, returns RUNNING (Wait) or FAILURE (Fail).	queue · BlackboardRef · pointer-style slot reference on_empty · string · default "Wait" · Choices: Wait, Fail	item · any