Create an offset deformation. If an input shape is provided, it will be deformed accordingly.

Input parameters:

1. Sh → Optional shape to offset.
2. Sd → Seed from which the offset is measured. May be a point, a plane, an infinite line, or a curve.
3. Fc → Function encoding the offset amount based on the distance to the seed. Ideally the function intersects $(0,0)$.

Output parameters:

1. Sh → Shape with applied deformation.
2. Df → Expansion deformation.