Perspective Exploration

Objective: Learn to identify the horizon line and vanishing points in perspective drawings.

1. Run the perspective applet at http://mathforum.org/workshops/sum98/participants/sanders/TryPersp.gsp.html and get a feeling for the behavior of a cube in two-point perspective.
2. Where is the horizon line in Inside St. Peter's (Magic of M.C. Escher #32)? Where are the vanishing points?
3. What's going on in House of Stairs (Magic of M.C. Escher #126)? There is a vanishing point in an arched doorway near the top of the picture. Find a curl-up that thinks the point is on the horizon, another that thinks the point is a nadir, and another that thinks the point is a zenith.
4. What's going on in Up and Down (Magic of M.C. Escher #139)?

Handin: A sheet with answers to all questions.