Blend sharp edges in a surface.

Input parameters:

1. Sf → Surface whose edges to blend.
2. Ed → Edge indices to blend.
3. Sz → Blend size.
4. Ty → Blend type.
   • 0 → Edge Distance
   • 1 → Rolling Ball
   • 2 → Rail Distance
5. Sb → Set back blend corners.

Output parameters:

1. Sf → Surface with blended edges.