main-q1009

OpenGL Programming

  • Are there FlTk Methods that generate primitive solids?
No - FlTk does nothing for 3D (except let you put up an OpenGl Window). OpenGL offers few "solids" - its all surfaces, but there are quadrics (spheres, ...)
  • Why can’t OpenGL “fake” normals?
No reason it couldn't. But it doesn't. No good reason. Some not so good ones (have to pick up/down, often want normals at vertices not faces)
  • How often does a vertex have more than one normal?
any time you want the "faceted" look (each triangle with its own face normal)
  • what needs to be done in visual studio to start drawing in 3D?
exactly the same things as in 2D (with OpenGL) - just add some opengl commands to your C/C++ program

Coordinate Systems

  • If we change the hand, does the arm move?
Not if you've defined your coordinate systems correctly
  • How do we rotate a set of 3D Objects?
just treat them as one (use the same transform for all of them)
  • How do we build a rotation matrix for a specific angle?
use the formulas (usually, use the 2D matrix)

OpenGL Implementation

  • Where is the Matrix Stack Implemented?
Some combination of hardware and the driver

Specific examples

  • Can we work through an actual example of calculating normals?
good idea
  • An example that uses push/pop
goog idea, but also see the homework
  • How do you know if 2 vectors are perpendicular
if their dot product is zero
  • How do we code a coordinate system in OpenGL?
that's Monday's lecture!

Stuff About Class

  • How much math on the midterm? Stuff from the book?
Lots of math, the stuff in the book is similar to stuff in lecture.
  • Can we have an OpenGL 3D demo?
Page last modified on October 11, 2009, at 08:51 PM