I think I have a decent idea about the lighting model for matte and spectral lighting. I am going to spend another hour or so working through what I need to implement to get matte lighting working, and then hopefully implementation will be quick. Things are looking better. I found an error in my color routines, so my shapes don't look so bad. Still, my image is upside down and I'm not totally sure why, but hey, I'm implementing a pinhole camera right!?!?