Module spatial 

Motion along spatial curves: a position keyframed with tangents travels along the cubic Bezier between its keyframes at the speed its timing curve sets, along the curve’s length.

Functions

motion_polyline

The polyline a spatial path between keyframe values draws, samples points per segment, for showing a motion path.

point_along

The point amount of the way along the curve from from to to, its control points from + out_tangent and to + in_tangent, measured along its length; all in a space scaled so lengths are as they are on screen.