一种大规模地形模型的视相关简化算法

View-dependent simplification algorithm of large-scale terrain model

提出了一种基于点删除的视相关简化算法。首先依据视锥准则、背离面准则和屏幕投影误差对原始网格进行可见性预处理 ,再对预处理后的网格依据顶点重要度大小进行点删除简化。重要度以顶点到平均平面的距离表示 ,在计算过程中 ,采用了距离加权的办法 ,从而进一步加强了视相关简化效果。实验表明 ,算法具有较高的绘制速度 。

This paper presented a view-dependent simplification algorithm based on vertex-removal. Firstly,the original mesh was preprocessed by such view-dependent criteria as view-frustum,surface orientation and screen-space geometric error. Then the preprocessed model was simplified further by the vertex-removal algorithm according to the vertex's importance expressed by the distance from the vertex to its average plane. To promote the effect of view-dependent simplification further, the vertex's importance was weighted by the distance from view point to mesh vertex during the calculation. Experiments showed that the algorithm could accelerate the rendering to a great extent and the rendering velocity was independent of the model complexity.