Accessing ThreeJS Objects

Often times, we'll want to access the actual ThreeJS objects that Threeagent is managing, so that we can leverage ThreeJS functionality. For instance, we might want to use ThreeJS's raycaster to pick objects in our scene, or use a physics simulation to directly drive the transformation of each object.

Threeagent provides a few ways to get access to the ThreeJS substrate.

Lifecycle Hooks

We can set the :on-added and :on-removed of any entity to a callback function that will be invoked with the ThreeJS object for that entity. The :on-added callback will be invoked after the object is first added to the scene graph. The :on-removed callback will be invoked after the object is removed from the scene graph.

There is also :ref which is an alias for :on-added.

Extending Threeagent

For more advanced use cases, we can define custom ISystem and IEntityType implementations to create and manage ThreeJS objects. See Extending Threeagent for more information.