Abstract: First, faceted model is used to represent a complex surface. Then, a physical model composed of a set of nodes connected by springs is construct ed. Solving for the equilibrium state of the energy function during flattening the 3D surface generates the 2D pattern. This method can efficiently solve development problems for complex surfaces. Accuracy of a developed surface can easily be controlled locally. Thus, compared to earlier methods, this approach provides more flexibility for solving CAD／CAM surface development problems.