具有线性精度的Cuberille方法

针对Cuberille方法精度低、显示效果差的缺点，将Cuberille方法形成的小立方体侧面边界作为骨架，在其基础上蒙上一层多边形网格．多边形网格通过扩张小立方体的侧面得到，这种扩张可以弥补由Cuberille方法造成的误差，从而使多边形网格具有线性精度．详细讨论了如何确定多边形网格顶点的位置、法向量以及多边形网格的构造方法，所构造的多边形网格具有明确的几何意义．最后，分析了算法的复杂性，并且以具体实例对新方法和Marching Cube方法及Cuberille方法在显示效果和时间消耗上进行了比较．

A Modified Cuberille Method with Linear Precision

A new method is presented for removing the shortages of the Cuberille method which has lower precision and poor image quality. Iso-surface(cube sides) produced by the Cuberille method is taken as a framework,and is covered with a polygon grid. The polygon grid is produced by expending the cube sides with a linear interpolation. This expansion improves the precision of the Cuberille method,and makes the polygon grid have linear precision. How to determine the position and normal at each polygon vertex and how to construct the polygon grid are discussed. The polygon grid produced with new method has clear geometric meaning. The normal vectors computed with new method are compared with those produced with Marching cube method. The result shows that the smoothness of the image is obviously improved. Finally,the complexity of the new method is discussed,and using an instance the Cuberille method and Marching cube method are compared on the effect and time consumption.