Research And Implementation Of 3D Roaming System Of City's Pipe Network

This paper discusses the roaming system of city's pipe network, key technology for pipe network 3D scenes, and methods to improve the relevant technology. A 3D roaming system of city's pipe network is developed.This paper briefly describes the basic technology of 3D roaming system development such as pipeline data extraction from CAD file, and Java3D based 3D modeling. Collision detection algorithm, shortest path algorithm and the automatic obstacle avoidance algorithm are researched, and a collision detection algorithm based on linear encoding octree and mixed bounding box algorithm is proposed, with the feature of pipe network, a method for improving the efficiency of the shortest path is adapted and a method for the automatic obstacle avoidance during automatic-roaming is proposed.Collision detection is a crucial issue in virtual environments. In this paper, a mix bounding box algorithm is proposed, which has the advantages of both AABB and OBB. With the problem of large amount of data and 'complexity of computation in 3D scene, this paper presents a linear coding based octree for scene management. Experiments show that the effective combination of the two methods above is very effective for improving the efficiency of collision detection.The shortest path and automatic obstacle avoidance is the basic problems for auto-roaming of pipe network. Dijkstra algorithm is a classical algorithm for solving the shortest path. In this paper, pipe network, with its spatial characteristics, elliptical and direction prefer algorithm is adopted to improve the efficiency of Dijkstra. With features of pipe's 3D model, an automatic obstacle avoidance roaming algorithm based on vector and offset is proposed in this paper. The two methods above have been effectively verified.Finally, the paper gives a summary of this subject in related fields and prospects.