Roto add points interpolation

[Yojimbo]

When you are doing a roto job of the live actor, sometimes a frame will come up where you realize your spline does not have enough points. Currently, when you add points to this closed spline, the new points have no keyframes and are stuck at the one spot where you added them throughout all the animation. This means you have to go back through every keyframe already done and integrate these points into the spline.

My request is that the program, when a new point is added, should interpoltae its position at every keyframe based on the two points around it. Every new point added must between two other points. Between those points is a line. The new point should always be placed half the distance between the two points on that line.