LOD Technology Based On Triangulated Irregular Networks

Visualization of terrain information is playing a key role in many applications such as military affairs, simulation system, visual reality civil engineering, geoscience, etc. LOD can solve the bottleneck problem of the current computer's processing magnanimity terrain data's visualization. This paper mainly discusses the methods of LOD based on irregular networks and the principal content and achievement in this thesis is as follow:· Some application backgrounds of LOD based on irregular grid are introduced. Its features, actuality and significance, and classifies are explored in this paper.· The related methods of large terrain data's visualization based on irregular networks are discussed, including magnanimity data's storage and management, visibility culling, back-face culling, hidden-surface culling, contour reserving, the algorithms of terrain's TIN and the methods of error's computing.· Some LOD algorithms based on irregular networks, which are representative, are compared.· An efficient LOD algorithm based on irregular networks is presented. The algorithm makes full uses of the scanning sorted data's features, adopts the dynamic blocked method, and also uses the algorithm of speedily Building TIN Based on Convex Shell, thus can triangulate the terrain data quickly. At the same time, the algorithm integrates triangle strips which can further accelerate terrain rendering.· A prototype system is developed by using C++ and OpenGL API. Real-time visualization of one larger terrain data sets is implemented on PC platform. Experimental results show that the algorithm in this thesis is efficient and supports real-time visualization of large scale terrain.