海底地形实时绘制技术研究和实现  

Research and Implementation on Real-Time Undersea Terrain Visualization Technology

作　　者：王晨明 苏天赟[2] 王国宇[3] 宋庆磊[2] WANG Chen-Ming SU Tian-Yun WANG Guo-Yu SONG Qing-Lei(Alcatel-Lucent Qingdao, Qingdao 266100, China The First Institute of Oceanography, SOA, Qingdao 266061, China College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China)

机构地区：[1]青岛朗讯科技通讯设备有限公司,山东青岛266100 [2]国家海洋局第一海洋研究所,山东青岛266061 [3]中国海洋大学信息科学与工程学院,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2016年第12期142-150,共9页Periodical of Ocean University of China

基　　金：海洋公益性行业科研专项(201205001);国家科技重大专项"大型油气田及煤层气开发"子任务(2011ZX05056-001-01)资助~~

摘　　要：为了提高大规模海底地形的绘制效率,LOD(细节层次,Levels of Details)技术必不可少。在ROAM(Real-time Optimally Adapting Meshes,实时优化自适应网格)算法的基础上,通过数据加载、视域剪裁、建立评价方法等技术手段,根据视点位置实时更新可视区域,避免了多余三角面片的生成和绘制。同时,采用对不共斜边节点强制分割的方法处理裂缝问题,通过索引坐标与实际坐标转换以及无效值处理实现任意范围海底地形对ROAM算法的应用,消除了传统ROAM算法对数据网格大小的限制,保证了绘制的效果和正确性。最后,通过GPU实时计算和绘制各顶点的法线和颜色,实现了大规模海底地形的实时建模和高效绘制,满足了高精度、海量海底地形漫游浏览的需求,特别是针对起伏比较大的地形漫游浏览。With the rapid development of computer graphics,the three-dimensional terrain modeling and visualization are widely researched at home and abroad.The speed of real-time rendering becomes the key factor to determine whether a three-dimensional visualization system is good.But the large amount of data has became the huge obstacles of three-dimensional visualization.Scholars at home and abroad used LOD（Level of Detail）technology widely to solve this problem.The main function of this technology is to simplify the part of flat terrain and distant objects,to reduce the number of drawing primitives,to improve the rendering efficiency under the premise of ensuring visual effects.The content of this paper is study the draw technology of large-scale three-dimensional terrain.It introduces the research status and development in the relevant field at home and abroad.LOD（Levels of Details）technology is essential on improving the efficiency of large scale terrain.The main purpose of this project is to study the seabed terrain rendering progress at home and abroad,to analyze the pros and cons of different ways,to obtain feasible solutions,to optimize programs on this basis,at last,to improve the rendering efficiency and to meet the authenticity.Based on ROAM（Real-time Optimally Adapting Meshes）algorithm,the display area can be updated in real-time according to the viewpoint position by means of data source processing,field crop and the establishment of evaluation methods,which can avoid rendering superfluous triangular facets.At the same time,the nodes,which have different hypotenuses,are compulsively split to solve the problem of crack.Through transforming from the indexical coordinate to actual coordinate and utilizing the NONE data value,then any scope of undersea terrain can be modeled and visualized based on ROAM,which can clear up the limit of mesh size and guarantee the rendering effect and correctness.By computing and rendering each vertex＇s normal and color with GPU,we accomplish the goal of large-scale t

关 键 词：细节层次(LOD) 二叉树 实时优化自适应网格(ROAM) 海底地形 评价因子 

分 类 号：P714[天文地球—海洋科学]