Now that we have some basic lighting, a physics plane, and the ability to create and simulate physics objects, it's time to start shooting things. Before we jump head-first into creating agents, we'll take a quick detour into accessing some of the physics aspects of sandbox objects, as well as interacting with input controls.

The Sandbox_HandleEvent function allows the sandbox to respond to mouse and keyboard inputs. The event parameter is a Lua table that stores the source of the event, whether the event was generated by a down or up key press, and what key caused the event. Mouse-movement events are similar, but contain the width and height location of the mouse cursor.

As we already know how to create a sandbox object, all we need to do to shoot objects is position the object at the camera's position and orientation and apply a physics impulse on the object.

In this case, we're going to create and shoot a block on a space_key press event. The camera's position and forward...