Work with behavior graph assets

In Unity, behavior graphs use two distinct but related asset types: BehaviorAuthoringGraph and BehaviorGraph.

The separation of these assets is intentional to optimize performance and maintain the necessary editor functionality.

  • BehaviorAuthoringGraph contains editor-specific model data that is used to visualize and edit behavior graphs.
  • BehaviorGraph is a runtime representation of the authoring data.
  • Each agent requires its own BehaviorGraph instance to track independent operation state.

Asset types

Each asset type serves a unique role in the workflow.

BehaviorAuthoringGraph

The key features of the BehaviorAuthoringGraph asset type are as follows:

  • The editable, authoring/design-time representation of your behavior graph.
  • Contains additional debug information and editor-specific data.
  • Visible in the Project window as the primary graph asset you create and edit.
  • An internal class that can't be directly referenced in gameplay code or components.

BehaviorGraph

The key features of the BehaviorGraph asset type are as follow:

  • The runtime representation of your behavior graph.
  • Optimized for performance by the removal of editor-specific data.
  • Exists as a subasset of BehaviorAuthoringGraph.
  • The only graph type that must be referenced in gameplay code and components.

Common issues

When you work with behavior graph assets, you might encounter issues related to asset assignment and runtime operation.

Assignment compatibility

If a field requires BehaviorGraph, you can't directly assign BehaviorAuthoringGraph to it because both these asset types perform different roles. The BehaviorGraphAgent component extracts the runtime graph from an authoring graph, but this capability isn't general purpose.

Finding the runtime graph

To assign a BehaviorGraph to a field, follow these steps:

  1. Locate the BehaviorAuthoringGraph in the Project window.
  2. Select the arrow next to the asset to expand it.
  3. Find and assign the nested BehaviorGraph subasset.

Best practices

Follow these best practices for authoring and runtime.

  • In the editor: Use BehaviorAuthoringGraph within the behavior graph editor to author and visualize.
  • In your code: Reference only BehaviorGraph assets for runtime operation. The asset should only act as an original reference, and you should create an instance of it (using ScriptableObject.Instantiate) before running it.
  • For components: Use BehaviorGraphAgent when possible, as it handles the correct setup and instance management.

Additional resources