The Viewer library provides a toolset for creating interactive 3D sketches in Processing. The Viewer library makes use of the OCD library, also written for processing. The library handles camera movement, using the keys W,A,S,D for movement and E for jump. The Viewer library also allows you to set x and z boundaries for the camera.
The following is a minimal example of the Viewer library to get you started. Note that if you run this, you won't see anything as there's nothing in 3D space to be seen.
import processing.opengl.*; import carlucci.viewer.*; //declare the camera Viewer cam; void setup(){ size(800,600,OPENGL); //create the camera and pass a reference to the applet cam = new Viewer(this); //that's it! }