提出了一种多分辨率网格的简化生成算法,对传统方法从两个方面进行了改进.首先,以三角形面片的法向量夹角为几何特征,对整个三角网格表面进行区域分割,使和给定种子面片具有相近几何特性的三角形网格能划分在相同的子区域;然后,以顶点重要度为准则,对所分割子区域内的三角形网格进行半边崩溃简化操作,以退化三角形面片的寿命值为依据,进行表面多分辨率的层次细化.为避免网格密度小的区域过度简化,各子区域内的网格简化按比例进行;同时边界点不能被崩溃替代,以防止模型在边界处发生变形.实验结果表明,该算法边界保形效果好,多分辨率网格生成效率高,占用存储空间小.
A method of the multi-resolution mesh model is introduced based on the half-collapse simplification.Firstly,the triangular facet of the entire mesh model is segmented regionally with the normal vector angle of the triangular facet as the geometric features,making the triangular facets and the given seed ones-both of which share similar geometric features-segmented in the same regions.Then,the method of half-collapse simplification is performed on all segmented regions according to the criterion-the vertex' s importance and the multi-resolution facet is gradually refined.Finally,in case of the regions where the triangle gets low density overly simplified and the model boundary reshaped,every region should be simplified proportionally and the vertexes of the boundary should be not replaced by the half collapse,respectively.It is founded experimentally that this method not only simplifies the model much well but also protects the boundary from being reshaped.Furthermore,this method outpefforms other methods in efficiency.