Fig. 6: TPMS lattice structures with complex external shapes.

a CAD model of the same vertebra with a Gyroid-type porous architecture by Boolean53. b The Tibia scaffold is composed of a Primitive-surface by shape function mapping method54. c TPMS lattice structures are designed based on solid T-splines55. d 2D design strategy for TPMS lattice structures with freeform shapes57.