目前多分辨率地形的生成准则主要是屏幕空间误差或其变相表达的地形粗糙度,但该类误差准则仅适于对近处的地形进行简化.为了能对远处的地形进行简化,因而从能量传播的角度出发,提出了一个适合对离视点较远的区域进行简化的残余能量准则,同时将其与屏幕空间误差相结合,建立了一个基于视觉原理的多分辨率地形生成准则,并给出了一个基于四叉树结构的实时生成算法.实验表明,该算法能有效减少三角形的数目,并能适合于大规模地形的实时显示应用.

There are two mainly error rules for the generation of multi-resolution model of terrain, one is screen space error, the other is terrain roughness, however, both of them are liable to reduce the area near or not very far from the viewer, because they discard 2 of 3 dimensions of a vertex. In this paper, first, a rule named remaining energy is proposed which is suitable for reducing the area far or very far from the viewer, the principium of the rule is that the light eradiated from surface will attenuate during its transmission, so the light energy eradiate from the surfaces far from the viewer will become too faintness to attract the viewer's attention, thus the surfaces far from the viewer can be emerged into larger surface, then the rule based on vision principle is formed by combining remaining energy rule and terrain roughness, in the end, an algorithm and its implementation based on quadtree for generating terrain multi-resolution model under the vision-dependent rule is described in detail, the algorithm can simplify the terrain effectively and is proven to be very valid for the reduction of large scale terrain at the same time.