Three dimensional apparel CAD system

Abstract

We are developing a three dimensional (denoted 3D, hereafter) CAD system for garments to help the process of pattern making. This is a process to create a 3D form of a garment by designing a two dimensional (2D, hereafter) paper pattern that realizes the 3D form. The core of the system is a simulator that estimates the 3D form of a garment put on a body from its paper pattern (2D→3D process) and a developing program to obtain the 2D pattern that minimizes the energy required to deform it to the given 3D shape (3D→2D process). In both processes, the specific anisotropy of the mechanical properties of cloths is considered. In the 2D→3D process, the contact problem with body and geometrical nonlinearity are also taken into account. The preprocessor for the 2D→3D simulator is quite unique in that it converts an arbitrary 2D paper pattern into a 3D surface, considering the topological operation, 'sewing'. Both the 2D→3D process and the 3D→2D process are formulated as nonlinear energy-minimum problems, and they are solved by our original method in about 10 minutes with our workstations. Once the 3D form is obtained, the color pattern of a given cloth is mapped and displayed. As a consequence of the mechanical calculation, the distributions of the distortion and stress of the cloth are also visualized. Such information may contribute to the design of garments with consideration of physical attributes as well as visual beauty.