When the shift key is pressed on the keyboard, horizontal moving of the mouse translates to moving in the Z-direction. This motion is not (yet) visible.

In the top half of the window draw the default view perpendicular to the x-y plane. In the bottom half of the window draw the side view perpendicular to y-z plane.

The double-view should be toggled when 4 is pressed.

When key 5 is pressed have a yellow dot travel around the closed curve. Draw the tangent (red) normal (green) and binormal (blue) of the curve at the yellow dot.