Interaction State Tree
The Interaction State Tree is provided by Interaction Targets and used by the Interaction Source. It defines all steps that occur during an interaction once it is activated.
By defining interaction steps in a State Tree, you can support very different interaction flows without writing custom code for each case. For example, in the same game you can have:
A chest that moves the player to a specific position, plays an Animation Montage, and then triggers the interaction on the chest actor.
A door that removes a key from the player's inventory, configures IK for the door handle in the player animation, and plays an Animation Montage.
A switch that checks the world state (for example, whether power is enabled) and, if so, finds a lift actor and moves it to the current level.
Interaction State Trees must always be created using the NinjaInteractionComponentSchema.
State Tree Design
You can use the State Tree elements provided by the Interaction System or implement your own. Keep the following design considerations in mind:
At some point, the Interaction Tree must execute the Interaction Behavior, usually using the Trigger Behavior Task.
When the interaction starts, the Interaction Tree is activated. You can track elapsed time within the tree itself and trigger the behavior once the elapsed time reaches the desired duration. Do not rely on input actions configured with a "Hold" trigger for this purpose.
Ensure that all states eventually terminate the Interaction Tree execution.
On failures, you should always release the handle, usually using the Release Handle Task.
Default State Trees
Ninja Interaction provides two default Interaction Trees for common interaction patterns:
Interaction Tree | Description |
|---|---|
Generic | Tracks accumulated time (if enabled) and triggers the interaction behavior. |
Animation | Similar to Generic, but triggers an Animation Montage event as part of the interaction flow. |