Precept 9, More on assignment 4

• my office hours are no more: hardly anyone showed up, so I've changed it into "send me e-mail to set up a meeting, or ask a question"
• an addition to the 2nd program: let the tetrahedron rotate around an axis which is not parallel to any of the coordinate axes (so x, y and z in your glRotate call should be non-zero)
• when the user inputs a mesh, don't bother to check if a new triangle will intersect existing ones. Extra credit if you do enforce correct user input
• another input idea: let the user set a number of points, then triangulate this point set. A triangulation algorithm is described in Graphics Gems IV, source code is available at the Princeton Graphics Archive (also extra credit for this one)
• in the 3rd program, the user can select a vertex and adjust its height. Extra credit if:
  • the user can also select a triangle and adjust its height
  • the user can select a point/triangle in the 3D view
• there was a lengthy discussion on the requirements for the data structure, and the problems one encounters when implementing local higher generations
• don't forget: realistic looking mountains will get you a high score. So if you have time and ideas, work on that. Some references (available in the E-quad library and in the Graphics Lab, do not take out these proceedings except for photo-copying):
  • trees: SIGGRAPH 85: p.305, SIGGRAPH 86: p.55, SIGGRAPH 88: p. 141 and 151, SIGGRAPH 89: p.31
  • clouds: SIGGRAPH 85: p. 297
  • mountains/terrain: SIGGRAPH 86: p.39, SIGGRAPH 88: p.262, SIGGRAPH 89, p.41