Abstract: A new modeling algorithm for realistic travelling Tai lake surface simulation in virtual environment is presented.With the introduction of Johanson’s projected grid algorithm which doesn’t use multi-resolutional LOD model and avoids the chapping problem，it transforms the grid mesh from view space to world space.To speed up the rendering frequency and avoid noise calculation for every lake mesh vertex，B-spline surface is introduced to construct lake surface.The Perlin noise is applied to the control point of the B-spline surface in order to control the water height field indirectly.So the water surface can be divided in high resolution without more noise calculation.The construction speed of B-spline surface is guaranteed by acceleration function of the graphic hardware.It turns out that this modeling algorithm can satisfy the requirements of real time simulation of realistic water surface on generic PC platform.

Key words: projected grid algorithm, Perlin noise, B-spline surface

摘要： 提出了一种面向虚拟漫游的太湖湖面建模算法。引入了Johanson投影网格法，避免了多分辨率LOD的龟裂问题，将视空间里生成的网格投影到世界空间中。为了提高渲染效率，避免对投影到世界空间中的每个湖面网格点进行噪声计算，采用了准均匀B样条曲面来构造湖水水面，将Perlin噪声施加于B样条曲面的特征控制点，间接地控制水面高度。依靠图形硬件的加速功能保证了B样条曲面的生成速度。实验表明，用该算法可以在普通PC平台上实时模拟漫游太湖的真实场景。

关键词: 投影网格法, Perlin噪声, B样条曲面