Behaviors

Behaviors

Babylon.js v3.1 introduced a new component-based tool: behaviors. A behavior is a simple class that can be attached to a target, where it provides a specific set of features. Those features are triggered by defined events.

General

A behavior is defined by the following interface:

• name: Returns the name of the behavior
• init(): This function will be called when a behavior needs to be initialized. This is before the attachment to a target.
• attach(target): This function will be called when a behavior is attached to a target. This is where the behavior will hook into useful events. Babylon.js will make sure that the scene is not currently loading when this function is called.
• detach(): This function will be called when a behavior is detached from a target. The behavior must clear any associated resources and unhook all events.

If behaviors rely on animation, the following static properties will be available:

• EasingFunction: Define the easing function used by animations
• EasingMode: Define the easing mode used by animations

You can add behaviors to any object implementing the IBehaviorAware interface (lights, cameras, or meshes, for instance). Every IBehaviorAware object provides the following entry points:

• addBehavior(behavior): Use this function to attach a behavior to a given target. If the scene is currently loading, this code will be delayed until scene completion.
• removeBehavior(behavior): Use this function to detach a behavior from a target.
• getBehaviorByName(name): Return a behavior with the given name or null if not found.
• behaviors: This read-only property returns the list of behaviors associated with the target.

Most of the time, behaviors are designed to work with specific kinds of targets.

There are both camera and mesh behaviors.

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