Making my way through the Mixing 2D and 3D objects recipe from the Processing 2 Creative programming cookbook source code on GitHub.
In this recipe I learned how to use the ENABLE_DEPTH_TEST and the DISABLE_DEPTH_TEST parameter inside the hint function at the beginning and end of the draw function to to enable and disable the z buffer. This means the first black square intersects the coloured 3D cubes, while the second white square is drawn on top of the coloured 3D cubes. The DISABLE_DEPTH_TEST parameter would be useful if you wanted to display user interface elements such as buttons, banners or instructional text on top of the 3D environment.
