Create a non-uniform knot vector for NURBS curves and surfaces based on control point spacings.

Input parameters:

1. Pt → Control point locations.
2. Dg → NURBS degree.
3. Ty → Knot vector spacing algorithm to apply.
   •  1 → Clamped Uniform
   •  2 → Clamped Chords
   •  3 → Clamped Roots
   • 11 → Periodic Uniform
   • 12 → Periodic Chords
   • 13 → Periodic Roots

Output parameters:

1. Kn → NURBS knot vector.