How to decrease the radius between a sphere centerpoint and a point P and find the new coordinates of point P?

Question

I got a point (p) rotating around another point (c) with a known constant radius (r). I also know the position of the two points at all time.

I would like to decrease the distance (r) between the two points, from lets say from 11 to 7. How can I define the new point (p) coordinates after decreasing the distance?

Answer 1

You can use this simple formula: c+(p-c)*ScalingFactor