1. First construct the largest contour surface, and then trim it with an extruded surface. (As shown in the figure below)
2. Use an extruded curved surface to fit the small contour lines of the head, and then use a four-sided curved surface to transition. (As shown below)
3. Use a boundary surface to construct the surface of the eye part, and then use an extrusion to construct the surface of the mouth. (As shown below)
4. Use the extruded surface to merge with the surface made in the previous step, and then use the offset to build the shape of the tooth. (As shown below)
5. Use boundary blending instructions to construct the surface of the bone area, and finally move and mirror the constructed surface. (As shown below)
