CSCI-6962 Advanced Computer Graphics, Fall 2005
Assignment 4: Radiosity

The goal of this assignment is to implement a radiosity solver to compute global illumination in simple closed room scenes with ideal diffuse surfaces.

The images below show the classic Cornell box scene from rendered at 2 intermediate points of the radiosity solution, the final solution and a smooth interpolation of the solution (at the same resolution).

Tasks

Download the provided source code below and the simple test datasets. Compile it on your favorite platform and try these sample command lines:
```
radiosity -input cornell_box.obj -size 500
radiosity -input l.obj -size 500
```
Once the viewer is launched you can rotate the scene with the mouse. The test scenes are simple polygonal models with normals facing inward, so GL has been configured to render only "front-facing" polygons. The "back-facing" polygons are invisible. Press "v" to toggle between the different visualization modes. (The default is RADIANCE which will be all black except the light sources until you finish your implementation.) Press "w" to view the wireframe. The quad mesh model is stored in a half edge data structure similar to assignment 2. Press "s" to subdivide the scene. Each quad will be split into 4 quads. Press "b" to blend or interpolate the radiosity values. Press "t" to tone map the image so your images are similar to the results in the original radiosity paper. Press "i" to make one iteration of the radiosity solver, press "a" to animate the solver (many iterations) and press "r" to reset the radiosity solution. Press "q" to quit.
The images below show visualizations of the material properties (using arbitrary GL lighting), the absorbed energy, and the form factors for light transfer between the outlined red square and the other patches in the model.
You need to implement the form factor computation and the radiosity solver. You can choose any method we discussed in class or read about in various radiosity references. For the Cornell box scene you do not need to worry about visibility (occlusions). To correctly render
In the Radiosity class, write the Iterate() and computeFormFactors(int i) methods.
Choose one extension of the basic (no visibility) radiosity method and implement it. For example: implement the visibility component of the form factor to render shadows, implement a "smart" subdivision scheme to refine the mesh in areas with a high radiance gradiant, implement progressive radiosity with the ambient term, compute the penumbra and umbra regions of an area light source for discontinuity meshing, etc. As necessary create new test scenes for your extensions. For extra credit implement additional extensions and/or visualization tools.
As usual, please document in your README.txt file your implementation and extensions, etc.