Subject: Fractal mountains

Q15: How are fractal mountains generated?

A15: Usually by a method such as taking a triangle, dividing it into 3 sub-triangles, and perturbing the center point. This process is then repeated on the sub-triangles. This results in a 2-d table of heights, which can then be rendered as a 3-d image. This is referred to as midpoint displacement. Two references are:

1. M. Ausloos, Proc. R. Soc. Lond. A 400 (1985), pp. 331-350.
2. H.O. Peitgen, D. Saupe, The Science of Fractal Images, Springer-Velag, 1988

Available online is an implementation of fractal Brownian motion (fBm) such as described in The Science of Fractal Images. Lucasfilm became famous for its fractal landscape sequences in Star Trek II: The Wrath of Khan the primary one being the Genesis planet transformation. Pixar and Digital Productions are have produced fractal landscapes for Hollywood.

Fractal landscape information available online:

EECS News: Fall 1994: Building Fractal Planets by Ken Musgrave

http://www.seas.gwu.edu/faculty/musgrave/article.html

Gforge and Landscapes (John Beale)

http://www.best.com/~beale/

Java fractal landscapes :

Fractal landscapes (applet and sources) by Chris Thornborrow

http://www-europe.sgi.com/Fun/free/java/chris-thornborrow/index.html