Automatic paper pattern making using mechanical development method of a curved surface on a plane surface.

Abstract

We developed a three-dimensional apparel CAD system which simulated draping and sample making processes. In this paper, we explain the draping system. Usually draping means a technique of making paper patterns by draping a cloth around a dummy. It is difficult to simulate the process directly. So, we separate the process into two sub-processes. The first process is to generate three-dimensional shapes of garments or to measure the shape of a human body. The second process is to develop the three-dimensional surface on a plane surface. Here we focus on the technique of the second process. The technique is based on a mechanical calculation using a finite element method. The system consists of the following sub-programs. 1) Input a three-dimensional curved surface. 2) Input the mechanical properties of material fabrics. 3) Input the indication of the area to flatten. 4) Input the boundary conditions. 5) Divide the area into the triangular elements. 6) Make an initial plane surface. 7) Calculate the plane surface which is best fitted to the three-dimensional surface. 8) Output the best fitted plane paper pattern. 9) Output the strain and stress distributions where the plane surface coincides with the threedimensional surface. Using this system, we can obtain the best fitted paper pattern. The stress and strain distributions are used to evaluate the paper patterns. When a three-dimensional curved surface is fixed, we can obtain many paper patterns according to the mechanical properties of material fabrics and locations of darts. Finally we give an example to show that this system is applicable to a real problem.