How to use Behaviour Tree


Add BehaviourTree component

To use the behaviour tree you need the BehaviourTree component.

There are two ways to add the BehaviourTree component.

Create GameObject with BehaviourTree component

  • Click the Create button in the Hierarchy window or right click in the window
  • Select “Arbor / BehaviourTree”
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Add BehaviourTree component to already existing GameObject

  • In the Hierarchy window, select GameObject to which BehaviourTree is added
  • Click the “Add Component” button in the Inspector window
  • Select “Arbor / BehaviourTree”
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Open BehaviourTree graph in Arbor Editor window

To edit BehaviourTree You need to open a BehaviourTree graph in the Arbor Editor window.

  • In the Hierarchy window, select GameObject with BehaviourTree component.
  • Click “Open Editor” button of BehaviourTree component editor in Inspector window.
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Also, if the Arbor Editor window is already open, it will switch if you select GameObjet with BehaviourTree component in the Hierarchy window.

Create Composite Node

  • Right-click the position of the graph where you want to create a node
  • Select “Create Composite” in the menu
  • Select the composite you want to create in the Composite Selection window.
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Create Action Node

  • Right-click the position of the graph where you want to create a node
  • Select “Create Action” in the menu
  • Select the action you want to create in the Action Selection window.
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For creating action script here

Customize ActionBehaviour

Connecting nodes

Route nodes, composite nodes, action nodes can connect parent-child relationships.

Connect to existing node

  • Drag the connection slot at the top or bottom of the node
  • Drop to the destination slot
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Create a new node and connect

  • Drag the connection slot at the top or bottom of the node
  • Drop at the position in the graph where you want to create the node
  • Select “Create Composite” or “Create Action” from menu
  • Select the script you want to create with various script selection menus
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Disconnect node

  • Right-click on the connection line or connection slot you want to disconnect
  • Select “Disconnect” from the menu
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Changing the priority of nodes

The priority order is determined by the positional relationship of the nodes between the siblings having the same parent.

  • If you want to lower the priority, drag the node and move it to the right.
  • If you want to increase the priority, drag the node and move it to the left.
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Delete node

  • Select the node you want to delete
  • Select “Delete” from the right-click menu in the graph, or press the Delete key
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Replace Composite

You can replace only composites later, leaving the node’s location and connection state intact.

  • Click the gear icon in the node header section or right click on the header section
  • Select “Replace Composite”
  • Select a composite from the composite selection menu.
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Replace Action

You can replace only actions later, leaving the node’s location and connection state intact.

  • Click the gear icon in the node header section or right click on the header section
  • Select “Replace Action”
  • Select a action from the action selection menu.
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Add Decorator

Decorators can be added to composite nodes or action nodes.

  • Click the gear icon in the node header section or right click on the header section
  • Select “Add Decorator”
  • Select the decorator you want to add from the decorator selection menu.
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For creating decorator script here

Customize Decorator

Insert Decorator

You can insert a decorator at an arbitrary position.

  • Mouseover near the center between the node header and main behavior.
    Or mouse-over over the center of the separator between the decorators at the position you want to insert.
  • Click “Insert Decorator” button
  • Select “Add Decorator”
  • Select the decorator you want to add from the decorator selection menu.
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Delete Decorator

  • Click the gear icon in the title bar of the decorator or right click on the title bar section
  • Select “Delete” from the menu
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Add Service

Service can be added to composite node or action node.

  • Click the gear icon in the node header section or right click on the header section
  • Select “Add Service”
  • Select the service you want to add from the service selection menu.
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Since there is no built-in script in the service, it is necessary to prepare the service script beforehand.

For creating service script here

Customize Service

Insert Service

You can insert a service at an arbitrary position.

  • Mouseover near the center between main behavior and node footer.
    Or mouse-over the center of the separator between services at the position you want to insert.
  • Click “Insert Service” button
  • Select “Add Service”
  • Select the service you want to add from the service selection menu.
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Delete Service

  • Click the gear icon in the title bar of the service or right click on the title bar section
  • Select “Delete” from the menu
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About menus

Graph menu

Right-click the graph to display the menu.

Item Contents
Create Composite Create a composite node.
Create Action Create a action node.
Create Calculator Create a Calculator node.
Create Group Create a group.
Create Comment Create a comment.
Cut Cut the selected nodes.
Copy Copy the selected nodes.
Paste Paste the copied nodes.
Duplicate Duplicate the selected nodes.
Delete Delete the selected nodes.
Expand all Expand all the selected node’s behaviour.
Fold all Collapse all the selected node’s behaviour.

Composite node menu

Right-click the header part of the node or click the gear icon to display the menu.

Item Contents
Rename Change the name of the node.
Show Comment Switch the display of the node comment field.
Replace Composite Replace it with another composite script.
Add Decorator Add a decorator.
Add Service Add a service.
Paste Decorator As New Paste the copied decorator.
Paste Service As New Paste the copied service.
Expand All Expand all the behaviour of the node.
Fold All Collapse all the behaviour of the node.
Cut Cut the node.
Copy Copy the node.
Duplicate Duplicate the node.
Delete Delete the node.

Composite menu

Right-click the title bar or click the gear icon to display the menu.

Item Contents
Copy Copy the composite.
Paste Values Overwrite it with the value of the copied composite.
(Only valid for the same type)
Edit Script Open the script editor.

Action node menu

Right-click the header part of the node or click the gear icon to display the menu.

Item Contents
Rename Change the name of the node.
Show Comment Switch the display of the node comment field.
Replace Action Replace it with another action script.
Add Decorator Add a decorator.
Add Service Add a service.
Paste Decorator As New Paste the copied decorator.
Paste Service As New Paste the copied service.
Expand All Expand all the behaviour of the node.
Fold All Collapse all the behaviour of the node.
Cut Cut the node.
Copy Copy the node.
Duplicate Duplicate the node.
Delete Delete the node.

Action menu

Right-click the title bar or click the gear icon to display the menu.

Item Contents
Copy Copy the action.
Paste Values Overwrite it with the value of the copied action.
(Only valid for the same type)
Edit Script Open the script editor.

Decorator menu

Right-click the title bar or click the gear icon to display the menu.

Item Contents
Move Up Move the order up.
Move Down Move the order down.
Copy Copy the Decorator.
Paste Values Overwrite it with the value of the copied decorator
(Only valid for the same type)
Delete Delete the Decorator.
Edit Script Open the script editor.

Service menu

Right-click the title bar or click the gear icon to display the menu.

Item Contents
Move Up Move the order up.
Move Down Move the order down.
Copy Copy the Service.
Paste Values Overwrite it with the value of the copied service
(Only valid for the same type)
Delete Delete the Service.
Edit Script Open the script editor.

Connection line menu

Right-click on the connection line to display the menu.

Item Contents
Go to Parent Node Scroll to the position of the parent node.
Go to Child Node Scroll to the position of the child node.
Disconnect Disconnect it.

Debug menu

Click on the “Debug” button on the toolbar to display it.

Item Contents
Show all data values Change to show the current value of all of the data line.
Hide all data values Change to hide the current value of all of the data line.

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