Fractal Mountains

1. How do we model mountains?
   • Lots of semi-random detail
   • Difficult to model by hand
   • Idea: Let computer generate random effect in controlled manner
2. Start with triangle, refine and adjust vertices
   • At each step of refinement, adjust height of vertices
   • Use scaled random numbers to adjust height

3. Details
   • What to use for h?

     Random number, Gaussian distribution, scaled based on level

     I.e., for deeper level, use smaller scale

   • May want to do first step manually

     Triangular grid, place peaks and valleys

   • Could use different h functions to simulate different effects

   • Automatic colour generation

     high == white

     medium == brown

     low == green

4. Results:
   • Not physically based, but...
   • Look good for little work
   • Don't look at from directly overhead

Readings: Red book, 9.5; White book, 20.3;

References; Fornier, Fussell, Carpenter, Computer Rendering of Stochastic Models, GIP, 1982