A hole in a whole face.

What if you want to do a picture frame, or a doorway and save faces? Well, with a little enginuity, and eight points, you will have a square with a square hole in the center all in one face.

• A discussion of the source code,
• An active example of this world (must have CP installed as your default VRML browser), and
• Exercises for you to try on your own.