CS448 Programming Assignment #3 --
Intro to a Real-Time Programmable Shading System

This assignment is due at the start of class on Monday, April 24.

Using the files in /usr/class/cs448/assignments/a3/ (on some machines access this as /n/snell/usr/class...) as a starting point, create a surface similar to either the marble, flame, or planet from Ken Perlin's lecture.

In addition, add a colored spotlight to illuminate the bottom-right part of the sphere, which is only dimly lit in the template program. The colored spotlight must be implemented as a second light, which will require that you write a light shader for it, and active that light shader in main.cpp.

The following pre-defined variables are available in light shaders, and may be helpful:

// Predefined light shader globals

vertex floatv S;           // light-space surface vector, normalized, w=0
vertex float Sdist;        // distance to surface point

Some additional comments on this assignment:

• You may use noise or environment map textures as building blocks, but you are not allowed to just create the surface as a single texture.
• Don't expect an exact match, just try to reproduce the character of the images. In particular, we don't expect an exact match for the lighting -- the diffuse and specular provided are close enough. And we certainly we don't expect an exact match from the noise function. The one I provided is a cheap 2D interpolated value noise, while Ken Perlin's images were generated using a better 3D gradient noise.
• We reiterate the statement from the last assignment: Don't invest infinite amounts of time on this assignment.
• Use the SGI machines in the graphics research cluster for this assignment.
• When you are done, type "cs448submit hw3 directoryname", where directoryname is the name of the directory containing the assignment files. This script will copy the files to our incoming-assignments directory. Note that re-submitting overwrites the previous submission. The cs448submit script lives in /usr/class/cs448/bin, (on some machines, /n/snell/usr/class/cs448/bin).
• Unless you get really fancy, your changes will probably be limited to simpshade.in, the setup_pixel_map function in main.cpp, and the light-setup code in main.cpp. You should turn in a printout of these files (and any other files you created or modified) at the start of class on April 24.