The 3D Rendering And Roaming System On Mobile Platform

With the rapid development of mobile Internet and continuous improvement of the performance of the mobile devices, as well as the increasing requirement of the system mobility, mobile platform is attracting increasingly more attention in industry and academia. The improvement of graphics processing power of mobile devices makes the three-dimensional rendering on mobile platform possible.The limitation of hardware is the main factor which affects 3D rendering performance on mobile platform, including limited CPU computing power, memory capacity and bus speed. Since these limitations are not so easy to overcome in a short time, we can enhance the efficiency of the three-dimensional graphic rendering by appropriate optimized method. This thesis is to present the design and implementation of a three-dimensional rendering and roaming system on mobile platform, together with the research work of scene organization, collision detection algorithm and progressive transmission algorithm on mobile platform. The main work of this thesis includes:(1) Improvement of three-dimensional scene rendering and roaming:scene rendering and collision detection consume most of the system’s resources in the process of rendering and roaming, this thesis aims at improving these two aspects. Due to the limitation of screen size on mobile devices, this thesis organizes the scene using Octree structure, which can cull the scene rapidly which is not necessary to render. After analyzing the different collision detection algorithms, the design and implementation the collision detection algorithm, which is suitable for mobile platform considering the limitation of computing power in mobile devices is described in detail.(2) Simplification method and progressive transmission algorithms for 3D model in the mobile environment:due to the bandwidth of the mobile environment and memory of mobile devices are limited, complicated three-dimensional model is not suitable for transmission over wireless networks, and rendering on a mobile device. This thesis analyzes the existing three-dimensional mesh simplification methods and progressive transmission strategy, implements a simplification algorithm which can maintain the appearance effectively, and designs a progressive transmission algorithm which consumes less resource to rebuild the meshes on the mobile device.(3) Implementation and the application of the 3D rendering and roaming prototype system based on mobile platform:this thesis implements the prototype system on iOS platform using virtual campus as an instance and tests the system with several models. The experimental results show that the system can render in real-time and roam 3D scenes using different models. Besides, the system can provide function of location-based services (LBS) and progressive transmission of the mesh model.