A triangulated irregular network (TIN) based chunk gridding algorithm for terrain rendering was presented considering the topological flexibility of TINs. The classic chunked level-of-detail (LOD) codes are mainly based on gridding algorithms of semi-regular triangular network (SRN) and easily produces redundant vertices. The new algorithm can create TIN without redundant vertices based on the Delaunay mesh generation procedure. The mechanism of redundant vertex creation of classic algorithms was pointed out after the review on the framework of the terrain rendering algorithm and the SRN based chunk gridding algorithm. Then the TIN based chunk gridding algorithm was discussed, with emphasis on the algorithm and its robustness of Delaunay mesh generation based on the Bowyer-Watson incremental point insertion technique, and the stripping algorithm of TINs was also addressed. Results show that the algorithm can greatly decrease the grid scale about 30% in typical numerical experiments, thus decreases the interim file sizes and improves the efficiency of subsequent terrain rendering．Key words: gridding algorithm|terrain.
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