Dear Dr. Lin,

Here is my very belated Lab#4A. There are nine objects in the scene: three towers and six rings. Pressing the 's' key solves the towers of hanoi problem, animating the individual ring moves. The 'r' key may be pressed at any time to reset the rings, the 'j' and 'k' keys may be pressed at any time to speed up and slow down the animation, and the x, y, and z keys may also be pressed at any time. Here's a full list of keys:

's' - start solving animation

'r' - reset the rings (any time)

'j' - speed up the animation

'k' - slow down the animation

'x' - increase the X coordinate

'X' - decrease the X coordinate

'y' - increase the Y coordinate

'Y' - decrease the Y coordinate

'z' - increase the Z coordinate

'Z' - decrease the Z coordinate