Animating the drape of different cloths must address complex physical behaviors. This particle approach uses optimizations that make it faster than earlier implementations and allow it to simulate behavior over time.

A fast, flexible, particle-system model for cloth draping : CG in textiles and apparel

Animating the drape of different cloths must address complex physical behaviors. This particle approach uses optimizations that make it faster than earlier implementations and allow it to simulate behavior over time. The modeling system presented computes the full trajectories of particles and not just the final positions. This offers several important advantages. Since the full history of each particle is known, hysteresis effects can be modeled accurately. The Kawabata (1980) experimental data for different textiles can be input directly to the model. The effects of external forces, especially those produced by wind or moving solid bodies, can be modeled accurately. Despite this extra dimension of detail, our system computes final positions considerably faster than the times given by Breen, House and Wozny (1994). Our model can be easily extended to simulate the effects of manufacturing processes or interacting bodies. In particular, high stresses of the kind that occur in manufacturing can only be modeled if the full trajectory of each particle is known. We have implemented our model as a C++ class library. Particle systems are more flexible than approaches using continuum mechanics. Our system's fast computation times, mainly due to the numerical solution of ordinary differential equations, compare favorably to approaches using a finite-element method. Therefore, our approach might be an interesting alternative for other engineering problems currently solved by a finite-element method, for example, the computation of minimal surfaces, heavy membranes, vibrating membranes and population dynamics.

A fast, flexible, particle-system model for cloth draping

In this survey, we present a contemporary overview of cloth modeling techniques. 19 modeling techniques are summarized and categorized by their main theoretical method: geometrical, physical, or hybrid. The techniques within each category do not follow well-defined patterns. We therefore generally report each work independently according to the chronology of publication. At the end of the discussion of all techniques, we summarize their features in a table. We conclude by speculating on future research directions that could optimize the agreement between the requirements of visual realism and physical accuracy. The recommendations for future work consider the different goals in textile engineering and computer graphics.

Computer graphics techniques for modeling cloth

This chapter discusses and reviews the fundamental science and technology behind fabric structure and mechanics. The chapter introduces the extent of knowledge regarding fabric deformations, such as tensile, bending and shearing, and a new kind of testing method based on image analysis to characterize fabric mechanical behavior. A general review of computer simulation techniques for woven fabrics and garments is also presented.

Structure and Mechanics of Woven Fabrics

Software based on nonlinear shell theory can simulate 3D motions related to real fabric-manufacturing processes. This simulation capability advances the technologies necessary for automating the textile and apparel industries.

Finite-element modeling and control of flexible fabric parts

A shear flexible shell theory is used to predict the drape of fabrics. The fabric is considered a continuous, orthotropic medium. Finite element formulations are used to numerically solve governing equations under specific boundary conditions. Initially, the fabric is assumed to be a flat plate, which goes through large deformation during the process of draping. The load (fabric weight) is applied in steps to the model. During each step, a Newton-Raphson iteration method is used to solve nonlinear equilibrium equations under current load level. The material characteristics used in the model are Young's modulus in the warp and weft directions, shear modulus, and Poisson's ratio. Simulation of a 30 × 30 cm fabric draped over a 12 × 12 cm table is achieved in less than eight minutes of CPU time on an IBM RS 6000 workstation.

A Physically Based Model of Fabric Drape Using Flexible Shell Theory

This paper presents a study of the effect of important fabric mechanical properties on drape. The study uses a mathematical modeling technique to simulate fabric drape. Young's modulus in the warp and weft directions, shear modulus, Poisson's ratio, and fabric thickness are the parameters studied in this work. Results of the analysis indicate that all of these characteristics have varying degrees of influence on drape. The validity of using experimental values of fabric mechanical characteristics obtained from the Kawabata evaluation system for fabrics is discussed. The most important requirement for obtaining a good simulation is the use of correct values for these parameters, obtained experimentally at conditions similar to drape.

Bijian Chen

Papers

A Physically Based Model of Fabric Drape Using Flexible Shell Theory

A Parametric Study of Fabric Drape