Behavior graph node types
The logic flow of the behavior graph begins at the start node at the top. You can then add further nodes to develop and expand your behavior graph.
The tables in this section provide information on the different types of nodes available in Unity Behavior along with their description.
Action node types
To use the Action nodes, select Add > Action.
| Node | Description |
|---|---|
| Create new Action | Creates a new action node. To use this node, select Add > Action > Create new Action. For more information, refer to Create a custom node. |
| Animation | To use the Animation options, select Add > Action > Animation. |
| Set Animator Boolean | Sets a Boolean parameter on an animator to a specific value. |
| Set Animator Float | Sets a float parameter on an animator to a specific value. |
| Set Animator Integer | Sets an integer parameter on an animator to a specific value. |
| Set Animator Trigger | Sets a trigger on an animator. |
| Blackboard | To use the Blackboard options, select Add > Action > Blackboard. |
| Set Variable Value | Sets the value of a given variable. |
| Conditional Guard | Returns success if the condition evaluates to true and failure if the condition evaluates to false. |
| Debug | To use the Debug options, select Add > Action > Debug. |
| Log Message | Logs a message to the console. |
| Log Variable | Logs the value of a variable to the console. |
| Log Variable Change | Logs the value of a variable to the console when it changes. |
| Delay | To use the Delay options, select Add > Action > Delay. |
| Wait | Waits for a specified number of seconds. |
| Wait (Range) | Waits for the duration specified between the Min and Max values. |
| Find | To use the Find options, select Add > Action > Find. |
| Find Closest With Tag | Finds the closest GameObject with the given tag. |
| Find With Tag | Finds a GameObject with the given tag. |
| GameObject | To use the GameObject options, select Add > Action > GameObject. |
| Attach Object | Sets the transform parent of a GameObject to another GameObject with an offset. |
| Destroy Object | Destroys a GameObject. |
| Don't Destroy On Load | Prevents a GameObject from being destroyed on load. |
| Instantiate Object | Instantiates a GameObject to the graph owner scene. |
| Set Object Active State | Sets the active state of a GameObject. |
| Set Object List Active State | Sets the active state of all the GameObjects on the list. |
| Navigation | To use the Navigation options, select Add > Action > Navigation. |
| Navigate To Location | Navigates a GameObject to a specified position using NavMeshAgent. Note that if NavMeshAgent isn't available, the node uses Transform. |
| Navigate To Target | Navigates a GameObject towards another GameObject using NavMeshAgent. Note that if NavMeshAgent isn't available, the node uses Transform. |
| Patrol | Moves a GameObject along way points using NavMeshAgent. Note that if NavMeshAgent isn't available, the node uses Transform. |
| Physics | To use the Physics options, select Add > Action > Physics. |
| Add Force | Applies physics force to the target Rigidbody. |
| Add Torque | Applies torque to the target Rigidbody. |
| Check Collisions In Radius | Checks for collisions in a specified radius around the agent. If a collision is found, the collided object is stored in [CollidedObject]. |
| Set Velocity | Sets the linear velocity of the target Rigidbody to a specific value. |
| Wait For Collision | Waits for an OnCollision event on the specified agent. |
| Wait For Collision 2D | Waits for a 2D OnCollision event on the specified agent. |
| Wait For Trigger | Waits for an OnTrigger event on the specified agent. |
| Wait for Trigger 2D | Waits for a 2D OnTrigger event on the specified agent. |
| Resource | To use the Resource options, select Add > Action > Resource. |
| Play Audio | Plays an AudioResource at the target location. |
| Play Particle System | Plays a ParticleSystem at the target location. |
| Scene | To use the Scene options, select Add > Action > Scene. |
| Load Scene | Loads a Unity scene. |
| Unload Scene | Unloads a Unity scene. |
| Transform | To use the Transform options, select Add > Action > Transform. |
| Look At | Rotates the transform to look at the target. |
| Rotate | Rotates the transform by an Euler rotation. |
| Scale | Scales the transform by a value. |
| Set Position | Sets the target's position to a specific location. |
| Set Position To Target | Sets the transform's position to a specific target position. |
| Set Rotation | Sets the transform's rotation to a specific Euler rotation. |
| Set Scale | Sets the transform's scale to a specific value. |
| Translate | Translates the target's position by a specific amount. |
Events node types
| Node | Description |
|---|---|
| Start On Event Message | Starts the subgraph after receiving an event message. You can change how the node responds to events using different modes: * Default: Triggers the node only when it's idle and no child node is running.* Restart: Ends all children nodes and then restarts the node.* Once: Triggers the node only once and stops to listen to the event channel. |
| On Start | This is the root of the behavior graph. You can use multiple On Start nodes in your graph. |
| Send Event Message | Sends an event message on the assigned channel. |
| Wait for Event Message | Use this node when you want the game character to wait to receive an event message on the assigned channel. |
Flow node types
| Node | Description |
|---|---|
| Create new Modifier | Creates a new modifier. To use this node, select Add > Flow > Create new Modifier. Modifiers affect how their connected subgraphs are run. For example, a repeat modifier causes its branch to perform its operation more than once. For more information, refer to Create a custom node. |
| Create new Sequencing | Use this node to create a new sequencing node. To use this node, select Add > Flow > Create New Sequencing. Sequencing nodes control how their connected branches flow. They control how sequences run and define the conditions for a sequence's completion. For more information, refer to Create a custom node. |
| Abort | To use the Conditional options, select Add > Flow > Abort. |
| Abort | Aborts the branch when the assigned conditions are true. |
| Restart | Restarts the branch when the assigned conditions are true. |
| Conditional | To use the Conditional options, select Add > Flow > Conditional. |
| Conditional Branch | Selects a branch based on whether the condition evaluates to true or false. |
| Switch | Branches off based on the Enumeration value. |
| Parallel Execution | To use the Parallel Execution options, select Add > Flow > Parallel Execution. |
| Run In Parallel | Runs all the branches simultaneously. You can set different execution modes in this node to handle parallel branches. |
| Wait For All | Activates a child when all parents have started this node. It can't restart until the child's subgraph has ended. |
| Wait For Any | Activates a child when any parent starts this node. It can't restart until the child's subgraph has ended. |
| Cooldown | Imposes a mandatory wait time between iterations to regulate action frequency. |
| Inverter | Inverts the result of the child action. A value of success becomes failure and a value of failure becomes success. |
| Random | Runs a random branch. |
| Repeat | Repeats the operation of a node. You can set different execution modes that define how and when the repeated task executes. |
| Sequence | Runs branches in order until one fails or all succeed. |
| Succeeder | Forces success for the child node. These nodes are useful in cases where you want to process a branch of a tree where a failure is expected or anticipated, without interrupting the processing of the sequence to which that branch belongs. |
| Time Out | Terminates the execution of its branch after a specified number of seconds. |
| Try In Order | Runs branches in order until one succeeds. |
Subgraphs node types
Unity Behavior supports subgraphs through the Run Subgraph node. This node provides two options: static or dynamic, depending on the assigned subgraph variable.
The static option embeds the subgraph directly into the behavior graph, so you can set its Blackboard variables directly through the Inspector. The dynamic option allows changing the assigned Blackboard through the linked Subgraph variable but restricts Blackboard variables access to a shared Blackboard Asset used as an interface.
To add a Run Subgraph node, follow these steps:
Right-click in the behavior graph editor and select Add > Subgraphs > Run Subgraph.
In the Inspector, select the Subgraph link icon.
To use a static subgraph, select the Assets tab and then select a behavior graph from the list to assign it to the node.
To use a dynamic subgraph, select the Variable tab and assign a Blackboard variable to dynamically reference the subgraph.
| Node | Description |
|---|---|
| Run Subgraph | Runs the assigned subgraph and return the graph's final status. This node embeds the subgraph statically into the current graph, so you can override the Blackboard Variables (BBVs) within the subgraph. Use this node when you want to modularize a feature that always uses the same set of data. |
| Run Subgraph Dynamically | This node dynamically assigns a subgraph using BlackboardVariable<Subgraph>. Unlike the static Run Subgraph node, this node doesn't embed the subgraph into the current graph, as the assigned BlackboardVariable<Subgraph> can change at runtime. As a result, the subgraph’s Blackboard isn't directly accessible. To work around this limitation, assign a Blackboard asset to act as an interface and enable data exchange between the current graph and the dynamically assigned subgraph at runtime. |
Sticky note
Use the Sticky Note node to add a sticky note to the behavior graph. To add a Sticky Note to your behavior graph, follow these steps:
- Right-click an empty area of the Unity Behavior graph editor.
- Click Add from the context menu.
- Select Sticky Note.
This adds a Sticky Note to your behavior graph, allowing you to annotate it as needed.