ex18: Draped Textures

Willem A. (Vlakkies) Schreuder
CSCI4229/5229 Fall 2026


Combines a large texture with a quadrangles to make a simple terrain viewer.

Note that when we exaggerate the Z direction, the normals are not changed.
With Z exaggeration the normals are no longer perpendicular to the surface, 
but the goal is to do lighting on the "true" Z values, and just exaggerate
the Z scale for visual effect without updating the lighting calculations.


Key bindings
  m           Cycle display modes
  l           Toggle lighting
  +/-         Increase/decrease vertical exaggeration
  a           Toggle axes
  arrows      Change view angle
  PgDn/PgUp   Zoom in and out
  LeftMouse   Pan horizontally
  RightMouse  Pan vertically
  0           Reset view angle
  ESC         Exit
