【作者】 李青青；

【导师】 孙以泽；

【作者基本信息】 东华大学 ， 机械电子工程， 2012， 硕士

【摘要】 现有机织物CAD系统的外观模拟功能可以快速获取所设计织物的外观效果,但只适合模拟部分织物,其二维模拟图像的真实感不足,用三维图像真实模拟机织物的外观已成为新的研究方向。本课题以计算机图形学和软件工程知识为理论基础,应用纺织专业知识,对地毯中纱线的三维几何形态进行了深入分析,建立绒圈的三维几何模型,进行光照材质设置,结合地毯空间几何模型和受力模型,实现了圈绒地毯的计算机三维仿真。具体研究内容如下：纱线模拟：首先从影响纱线的几个主要因素颜色、纱支、捻度、捻向、光照性能等入手,建立纱线受力模型,模拟纱线中心线的轨迹,结合Peirce模型模拟纱线的横向几何特征,得到纱线的建立了纱线的三维模型。结合纱线的基本光照材质参数设置,模拟出纱线的真实光照效果,实现纱线的三维仿真。绒圈模拟：本文采用简化绒圈为单纱绒圈,细化绒圈表而细节的方法,建立绒圈模型。绒圈在地毯中并不是按照设计图规则排列,绒圈会发生错位、挤压变形、甚至高低圈遮挡。在地毯的整体效果模拟时,必须将这些因素考虑在内。地毯模拟：在Open Inventor三维图形系统中采用Phong模型建立地毯织物表面纱线的光照模型。根据光源的强度、位置等结合纱线的材质、结构、捻度和纱线在织物中的位置研究织物表面颜色明暗变化规律,并最终模拟地毯织物的外观效果。调整摄像机的位置和方向,可以从不同的角度观察仿真结果。通过本研究方法模拟的地毯织物外观的3D模拟效果图和实物对比,模拟图能够逼真的模拟地毯中的圈高变化,实现了二维模拟难以实现的仿真效果。更多还原

【Abstract】 In recent years, fabric designers are unsatisfied with the CAD/CAM system for woven fabric, for it is not able to provide a live image of the appearance 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 purpose of the research project.The goal of the research is the modeling and simulation of the geometrical appearance of yarn and tufted carpet in a 3D manner. The knowledge of carpet, theory of computer graphics and object-oriented programming technique is employed, and 3D geometric property of loop pile in the fabric is thoroughly investigated. Loop pile modeling and rendering technique is developed based on the theories of carpet geometry and mechanics. Specific researches are as follows:The yarn model is focused on some main factors, such as color, count, twist, direction of twist and illumination. The 3D geometry model of yarn is established through yarn stress model, the trajectory of centerline of yarn, combining Peirce model of the transverse geometric features. The basic lightening and material model of yarn is also employed to simulate the illumination of yarn in the physical world.The loop pile model is established based on the simplified loop pile composing of a single yarn and thinning hair circle surface detail. Loop pile in the carpet won’t be evenly arranged regularly as in the design paper; the loop pile may bend, move forward or back ward, move up or down even overlapped between the high and low loop pile. In the overall effect of the carpet simulation, these factors must be taken into consideration.Phong shading model and Open Inventor 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 yarn to enhance the rendered image. By changing the camera, the image can be observed from different point of view.Comparing with the simulation result and the picture of the carpet, the 3D image could reflect the pattern just because of the height difference. The 3D simulation of tufted carpet is both feasible and effective, which is better than plane simulation.更多还原