开展用计算机生成具有中国民族特色动画的研究，对弘扬我国传统艺术和提高中国动画片竞争力都有重要意义。祥云图案历史悠久，是最富有中国特色的吉祥图案之一，现有的大部分研究工作主要针对真实感烟云的模拟和绘制，而对生成中国传统风格祥云动画的研究工作还很少。为此提出一个祥云动画生成模型。首先利用椭圆来构造云朵的骨架曲线，沿着曲线上的非均匀分布点排列多个半径不同的基本圆，然后通过对这些基本圆进行求并运算来生成云朵内部区域和轮廓线；通过控制基本圆沿以分布点为圆心的圆周上运动，来生成连续变化的轮廓线和云朵形状；利用轮廓线上的运动点作为起点，沿中心点方向绘制云尾内卷线条。实验结果表明，利用该模型用户可以生成各类具有中国传统风格的祥云动画。

Study on computer generation of animations with Chinese traditional styles is of great importance for carrying forward Chinese traditional arts and enhancing the competitiveness of Chinese animations. Propitious clouds are one of the most typical Chinese-style auspicious patterns with a long history in China. However, most of previous research focuses on realistic cloud animations, while little effort has been paid to the cloud animation with traditional Chinese style. In this paper, a cloud model with traditional Chinese style is presented. First, we construct the cloud skeleton curve by use of eclipses, we then arrange a series of primitive circles with different radiuses along with points in the curve and obtain the cloud silhouette by a union of these circles. We construct the animation of silhouettes and cloud shapes by control primitive circles moving along the circumference whose center is on the skeleton curve. We take a dynamic silhouette point as start position and draw a spiral curve along the center of cloud. Experimental results show that the proposed model is able to generate a wide variety of animations of clouds in the traditional Chinese style.