与视点相关的多分辨率地表模型简化算法

为了提高交互式显示复杂三维模型的效率,针对规则地表模型提出一种多分辨率简化算法,充分利用帧间相关性加速动态简化过程。算法采用自适应四叉树结构判定地表模型可见性区域,减少绘制过程中处理的数据量。同时根据帧间变化的规律性,按照相邻帧间显示状态发生改变的顶点集合来局部修改需要绘制的三角形链表,并对其进行可见性裁剪,从而快速得到当前帧的简化网格模型。实验结果表明,该算法有效减少了简化计算量,对中等规模地形绘制速度可达到15帧/s,基本能满足交互式漫游的实时性要求。

View-dependent and multi-resolution simplification algorithm of a terrain model

View-dependent simplification and multi-resolution representation is an effective method for interactive visualization of complex 3-D models. A multi-resolution algorithm was developed for regular terrain models with frame coherence used to accelerate the dynamic simplification. The algorithm uses a self-adaptive quadtree structure to determine the visible area of the terrain mesh to reduce data processing during rendering. The rendering triangle list of the last frame was modified locally based on the changed vertex set between coherent frames to quickly generate the rendering triangle list for current frame. Experiments demonstrate that the algorithm effectively reduces the computational time and reaches a rendering speed of about 15 frames/s, sufficient for real-time interactive navigation over a terrain model.