花式纱线的计算机模拟

为了解决由于花式纱线不规则的外形、复杂的材质结构以及丰富的色彩变化，造成真实感模拟的困难，将花式 纱线的特征参数分为形态、材质和颜色三个主要方面，提出在计算机上模拟花式纱线的实现方案．用多段拼接的低次贝 塞尔曲线构造花式纱线的形态轮廓，在形态轮廓区域内及其附近添加基于光照明模型的光照明因子模板和随机噪声函数 表现纱线的材质，纱线的配色在色调、亮度、饱和度（hue、luminance、saturation,HLS)颜色模型中进行，可以单色平 铺和多色渐变．对棉质单色雪尼尔纱、波纹纱以及渐变色雪尼尔纱的模拟效果表明，整套方案能够实现对花式纱线较为 逼真的模拟．

Numerical simulation of fancy yarn

Fancy yarn with irregular shape,complicated texture and structure,and multicolor is difficult to model.Shape,material texture and color were selected as the critical characteristic parameters of fancy yarn,and a scheme for numerical simulation of fancy yarn on the basis of the three parameters was presented.Segments of lower degree Bezier curves connected one after another to construct the yarn shape.Illumination factor template based on a classic illumination model and random noise function were adopted to represent the material texture in and around the shape contour.Fancy yarn was colored with a single color or gradation colors in hue,luminance,saturation(HLS) color model.Simulation results on chenille yarn and wave yarn made of cotton show that the proposed scheme can render realistic appearance of fancy yarn effectively.