I found this post that helps clarify how to go from 2D to higher dimensions: https://math.stackexchange.com/questions/577641/how-to-calculate-interpolating-splines-in-3d-space
I found this post that helps clarify how to go from 2D to higher dimensions: https://math.stackexchange.com/questions/577641/how-to-calculate-interpolating-splines-in-3d-space