This class is the base for any object that generates (“publishes”) events. Whenever

an interesting event happens, Sim.Publisher iterates through its list of registered

callbacks, calling each with the event data and the supplied object (“subscriber”).

Sim.Publisher is the base class for most Sim.js objects.

The Application class (Sim.App)

This class wraps all the Three.js setup/teardown code for a page, such as the creation

of the renderer, the top-level scene object, and the camera. It also adds DOM han

dlers to the Three.js rendering canvas to handle resizing, mouse input, and other

events. Sim.App also manages the list of individual objects for the application, and

implements the run loop.

The Object class (Sim.Object)

This is the base class for most of the objects in an application. It manages the state

for a single (application-defined) object, and handles a few Three.js basics, includ

ing adding/removing the object from the scene, adding/removing children from

the object hierarchy (more on this shortly), and setting/retri