Abstract:  The fractal theory is adapted to resolve the simulation of irregular-shaped objects, however, the modeling technology is adapted to the modeling of regular-shaped objects. It can simulate the nature scenery to the life by combining the iteration function system（IFS）of fractal theory with the free surface modeling technology. With the application of iteration function system and the free surface modeling technology to computer aided design (CAD) environment and used the interface modeling Object ARX of CAD and Visual C++ to study the simulative algorithm of natural scenery. With the use of iteration function system to simulate the algorithms of 3D fractal plants. It applied the free surface (B-spline surface) to simulate a hillside. The practical application of a hillside and plants with fruit was given, it indicated that the simulative effect was natural and living.

Key words: Fractal theory  ,  ,  Iteration function system ,   , Scenery simulation

摘要： 分形理论适合于解决不规则形态物体的模拟问题,而造型技术适合于规则形态物体的建模。分形理
论中的迭代函数系统(IFS)和自由曲面造型技术相结合可以逼真地模拟自然景物。将迭代函数系统和自由曲面造
型技术应用于计算机辅助设计(CAD)中,应用CAD 与VC++的接口模块ObjectARX 来研究自然景物的模拟算
法。利用迭代函数系统模拟三维分形植物的算法,采用自由曲面(B样条曲面)技术绘制的山坡。给出了模拟种植果
树的山坡的综合实例,结果表明模拟效果自然、逼真。

关键词: 分形 ,  , 迭代函数系统 ,  ,  景物模拟