My model, the “Peacemaker,” is a humanoid robot. The model features 22 adjustable parameters, including the “flat mode” slider that folds the robot into a wheeled tank. The most important feature is an extrusion primitive that extrudes one sequence of points (the curve) along a different sequence of points (the path). Each point consists of a u coordinate, a v coordinate, and a Boolean stating whether the point is smooth (adjacent polygons have the same normal) or an edge (adjacent polygons have different normals). Almost every surface in the model is specified with this primitive.