CS116b/216 Spring 2014Practice Final

To study for the final I would suggest you: (1) Know how to do (by heart) all the practice problems. (2) Go over your notes at least three times. Second and third time try to see how much you can remember from the first time. (3) Go over the homework problems. (4) Try to create your own problems similar to the ones I have given and solve them. (5) Skim the relevant sections from the book. (6) If you want to study in groups, at this point you are ready to quiz each other. The practice final is below. Here are some facts about the actual final: (a) It is comprehensive (b) It is closed book, closed notes. Nothing will be permitted on your desk except your pen (pencil) and test. (c) You should bring photo ID. (d) There will be more than one version of the test. Each version will be of comparable difficulty. (e) It is 10 problems, 6 problems will be on material since the midterm, four problems will come from the topics covered prior to the midterm. (f) Two problems will be exactly (less typos) off of the practice final, and one will be off of practice midterm.

1. Briefly explain how ray-tracing works. Explain how to test if a ray intersects a sphere.
2. What is a shadow ray? How can we simulate area light sources in ray tracing?
3. Give the general form of a bidirectional reflection distribution function. Explain each part of your equation. Give three common techniques for determining a BRDF.
4. What is the reflection equation? What is distribution ray tracing? What is color bleeding? What is a caustic effect?
5. Explain how you tried to code a ray tracer using a fragment shader in HW4.
6. What is triangle soup representation? What is winged-edge representation. Show how to represent a tetrahedron in each.
7. What is an R-set? Give a CSG representation for the intersection of a unit sphere centered at the origin with a cube with vertices (0,0,0), (1,0, 0), (0,1,0), (0,0,1), (1,1,0), (0,1,1), (1,0,1), (1,1,1).
8. Briefly explain the algorithm for converting between CSG and boundary representation.
9. What is smooth skinning? In our SDL set-up how did we suggest updating the particles in a particle system before rendering them? What is damping?
10. Briefly describe how to write a simple WebGL program.