Research On 3D Imitation For Displaying Structure And Pattern Of Woven Fabric

In recent years, fabric designers are now unsatisfied with the CAD/CAM system for woven fabric ,for it is not able to provide a live image of the appearance and pattern of the fabric designed, and the system can only display part of the fabrics with 2D image. Therefore, the software engineers are trying to develop advanced system to provide a vivid 3D image for various woven fabrics, this is the very purpose of the research project. In order to develop the software concerned, the structure of the woven fabric has to be accurately calculated. The traditional woven fabric structure models, or Pierce model and its derivatives, are firstly discussed in the dissertation. The traditional model performs well in the calculation of the fabric with short floats. Unfortunately, it proves to be not successful in dealing with the fabrics with long floats. In this research, a new model pattern considering the float is created to study the fabric structure. As we know, pattern or interlacing is the most important factor that affects the fabric structure. The distribution and the length of the floats in the weave will change as the pattern changes. The main purpose of the new model is to study the effects of the floats on the fabric structure. By analyzing, it is revealed that the functions of the float may be summarized as follows: (1) to determine the appearance and the pattern of the fabric. The longer the float, the more the yarn may project or sink. Under the light, the surface effect appears due to shading. (2) to gather the yarns within a float or separate the yarns of a float from the yarns of another float. (3) to overlap the neighboring yarns. The difference of the height of the neighboring yarns is large and the yarns will determine the cramming character of the yarns. Yarns in the fabric won't be evenly arranged as in a the design paper; the yarns may bend, move forward or backward, move up or down even overlap. Taking this into consideration, we may set up a series of testing equations regarding the setts, yarn counts, fiber types, flatness, to calculate the structure of the fabric. Taking the mutual intervention between the neighboring yarns into account, the B-spline curve is adopted to describe the yarn in the 3-dimensional space. Shaping model is used to show the fabric effects under the lights. , Gouraud Shading model is used and OpenGL are used in the project. Furthermore, texture mapping technology is also used to reflect the twist, roughness and other characters on the surface of the yarns to enhance the rendered image. In this project, a new software displaying the appearance and the pattern of the woven fabric is developed. Testing results show that it is suitable to both the long-float and the short-float weaves. The imitated image can reflect the surface characters of a given weave with a great satisfaction. Comparing with the Pierce model and its derivatives, it is certain that the model provided by this paper, combining the floats and B-spline curve ,is a better way to calculate the structure of the woven structure.