一种四叉树地形渲染裂缝的改进消除算法

系统仿真学报 ›› 2015, Vol. 27 ›› Issue (7): 1520-1525.

一种四叉树地形渲染裂缝的改进消除算法

万明¹, 梁霞², 张凤鸣¹

1.空军工程大学航空航天工程学院,西安 710038;
2.空军司令部,北京 100038

收稿日期:2014-07-03 修回日期:2014-12-30 出版日期:2015-07-08 发布日期:2020-07-31
作者简介:万明(1979-),男,江西南昌人,博士,讲师,研究方向为飞行仿真与虚拟现实技术;梁霞(1979-),女,云南昆明人,硕士,研究方向为航空电子技术;张凤鸣(1963-),男,四川梁平人,教授,博导,研究方向为智能信息处理。

Improved Crack Removing Algorithm for Quad-Tree Terrain Rendering

Wan Ming¹, Liang Xia², Zhang Fengming¹

1. Aeronautics and Astronautics Engineering College, Air Force Engineering University, Xi'an 710038, China;
2. Air Force Command, Beijing 100038, China

Received:2014-07-03 Revised:2014-12-30 Online:2015-07-08 Published:2020-07-31

摘要/Abstract

摘要： 在大地形三维多分辨率显示中,针对裂缝消除问题提出了一种基于LOD (Level of Detail) 控制和裂缝可视性的改进算法。证明在四叉树网格可视距离/尺寸比>3时,必然满足限制四叉树约束;基于裂缝的可见性,在预处理阶段通过区分地形上升裂缝和地形下降裂缝,为后者添加与裂缝大小一致的几何图形来生成裂缝消除补丁;在实时渲染过程中,既不需要通过CPU计算来控制网格的层次差,也不需要通过CPU来识别相邻网格层次差和消除裂缝。实验测试表明：该算法简单有效,附加网格数据比裙边算法减少约75%,且完全能够避免地形裂缝的显示。

关键词: 限制四叉树网格, 地形渲染, 多分辨率, 地形裂缝, 裂缝补丁

Abstract: In 3D large scale multi-resolution terrain rendering, an improved algorithm based on LOD control and visibility for crack removing was proposed. It is proved that quad-tree grid is restricted while the ratio of visible distance to grid extent is large than 3. In preprocess stage, cracks were classified to raise crack and dropped crack, and crack patches with the same size as cracks were generated and attached to the latter. In real-time rendering stage, no special calculation by CPU for restriction of level of detail or for crack removing between adjacent grids was needed. Example shows that the algorithm is simple, reduces additional patches about 75% than traditional skirt algorithm, and removes cracks efficiently.

Key words: restricted quad-tree grid, terrain rendering, multi-resolution, terrain crack, crack patch

中图分类号:

TP391

万明, 梁霞, 张凤鸣. 一种四叉树地形渲染裂缝的改进消除算法[J]. 系统仿真学报, 2015, 27(7): 1520-1525.

Wan Ming, Liang Xia, Zhang Fengming. Improved Crack Removing Algorithm for Quad-Tree Terrain Rendering[J]. Journal of System Simulation, 2015, 27(7): 1520-1525.

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