Keyboard controls for light position and direction. Initially, the light object is at 0, 4, 0 and is rotated 90 degrees clockwise about its x-axis so negative z-axis is pointing at origin. The yellow line is aligned with the object's negative z-azis. (I.e. it is "looking" down at the origin):

• a, d - move light left, right (along its x axis)
• w, s - move light down, up (this is "forward" and "back" where light actually moves up/down along its z axis; notice that as you press the w key, the shadow gets larger)
• r, f - move light farther, closer (this is "up" and "down" where light will move along its y axis)
• i, k - look up, look down (light will initially turn away/towards you)
• j, l - turn left, turn right (rotate about world y, so has no effect initially)
• O - face origin (must not be aligned with y axis!)
• I, J, K, L - orbit down, right, up, left about origin
• x, X, y, Y, z, Z - positive/negative rotations about light's own axis
• SPACE - pause rotation of cube