Figure 3.

(a) Process of parametric curve bending for straight pathway. Straight segment passing through p0, p1, p2, and p3 is original pathway. Points (p1+, p2+) and (p1–, p2–) are those after applying slightly right and left shifts for (p1, p2), respectively. Parametric curve fitting was performed on either (p0, p1+, p2+, p3) or (p0, p1–, p2–, p3) to form curved bending pathway. (b) Smoothing process for sharply folded pathway. Red line and blue curve represent pathway before and after parametric curve fitting, and red points are used to solve parametric parameters.