QUOTE(BitSlapped @ 06/13/09, 06:00 AM) [snapback]309394[/snapback]
Seems to be something to do with normals
No its how calculus defines a curve. See a space curve is not 3dimensional its 2.5 dimensional and thus it cant solve all directions perfectly without outside input. (it really does NOT have a normal at all, it has curvature wich along with tangent helps predict a normal but its dependent on wich way you turn, and not stable solution, this all is easy in 2D since you can just define a binormal and calculate normal based on that but the binormal also needs to change in 3D and all bets are off)
Put the curve on a surface and move the surface about!
Well yes the iteration could forward calculate the solution in different way but that would need a change in the node.