Gimbal Lock

http://www.hq.nasa.gov/alsj/gimbals.html

This is a page I found that discusses gimbal angles and the singularities that can occur. The second part is a conversation between Apollo 11 astronauts and ground control. Thought I would share...

--tb

Multiple Rays

That is a good observation. They should be very close. I reverse engineered the curves from some incomplete documentation so there may be some errors in the definition/placement of the curves.

Homework 1

I noticed that if I varied my initial incoming ray around y=20.3 the focal length varied as well, but very little. I'm pretty sure this is to be expected, but I just wanted to check.