大规模3维地形管理关键技术研究

阐述了构建大规模3维地形模型的关键技术，包括地形分块技术、地形层次细节构建、可见性剔除和基于视点的渲染技术。为了提高绘制的帧率，实现大规模3维地形漫游系统显示的平滑和连续，本文采用了基于四叉树结构的地形的连续多分辨率渲染；在考虑视点和地形粗糙度的基础上，设计了一种合理的节点评价系统；提出了限定四叉树的三角网剖分方法，有效消除了不同分辨率节点间的裂缝。实验结果表明，在保证地形真实感的前提下，这些技术实现3维地形显示可以获得较好的图形质量和显示速度。

Key Technology with Large-scale Three-dimensional Terrain Management

This paper describes the key techniques for constructing a large scale 3D terrain scene, including terrain segmentation, Level of Detail （LOD） construction, visibility culling, view-dependent rendering. This paper realizes the terrain multi-resolution representation by quad-tree for enhancing the frame rate and realizing the display smoothness and continuity of the large-scale scene walkthrough system; a reasonable node evaluation system is designed, which is based on the consideration of viewpoint and terrain roughness; for eliminating the cracks between the nodes of different resolution, restricted quad-tree triangulation method is put forward. The experiment result presents that the terrain visualization gets good rendering quality and displaying rate by the technology of this paper on the premise of keeping terrain photorealistic.