大规模点模型的实时高质量绘制

提出了一个针对大规模点模型的实时高质量绘制算法．该算法采用距离相关的自适应绘制策略，在不损失绘制质量的前提下简化了计算．在预处理阶段，对点模型进行剖分，为每一分片分别建立层次结构，并序列化为线性二叉树保存．绘制时，首先根据每片的包围盒和法向等信息进行快速视域裁剪与背面剔除．对于可见的分片，依据它与视点的距离和视线方向，选择恰当的细节层次，直接取出线性二叉树中对应的点几何数据，自适应地选择最合适的绘制模式对其进行绘制．为了减少存储空间的消耗，该文提出了一种面向保留模式图形硬件加速的点模型压缩和解压缩算法，压缩比例达到8：1．作者在可编程图形硬件中实现了该文算法，在普通微机上实现了百万数量级点模型的实时高质量绘制。

High Quality Real-Time Rendering of Large Scale Point Model

This paper proposes a real time and high quality rendering algorithm for large scale point models. First it introduces a distance dependent adaptive rendering scheme which reduces the computation without loss of quality. As a preprocess, large scale point model is subdivided into multiple patches and a hierarchical structure is built for each patch and converted into a linear binary tree. During rendering, the model is processed patch by patch. Fast view frustum and back face culling, based on respective bounding box and normal cone, are first performed to determine invisible patches. Visible patches are then rendered by choosing appropriate rendering mode and view dependent level of detail. For determined level of detail, corresponding point geometry is accessed from the linear binary tree. Adaptive distance dependent rendering is accomplished to select point geometry, yielding better performance without loss of quality. In addition, This paper proposes a fast compression and decompression technique and achieve 8 times compression ratio to store all geometry information in local video memory. By exploiting the power of programmable graphics hardware, the proposed algorithm achieves real time high quality rendering in consumer PCs.