基于AOI的大规模三维虚拟场景流式传输机制研究

项目名称： 基于AOI的大规模三维虚拟场景流式传输机制研究

项目编号： No.41501432

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 苗茹

作者单位： 河南大学

项目金额： 20万元

中文摘要： 流式传输对解决由于网络带宽限制造成的大规模三维虚拟场景传输不能满足客户及时性需求具有重要意义。针对已有研究中对场景兴趣区域的判定、三维模型重要性程度的量化以及网络传输机制等薄弱环节，本项目提出基于用户兴趣区域（AOI）的预下载策略，建立流式传输机制。包括：（1）分析用户对场景区域的关注程度，结合三维模型本身的特点建立AOI提取模型，并依靠用户历史运动轨迹预测下一步场景。（2）提出基于三维模型的几何特征、空间分布、纹理特征和拓扑关系等重要性度量因子。（3）基于视觉特征确定适于本研究的三维模型简化算法，构建三维模型流式编码。（4）基于AOI确定的潜在可视场景集和自适应流媒体技术建立“边传输，边显示”的流式传输机制，并构建原型系统展开实验。本项目拟结合大规模三维地形和数字城市数据，利用建立的流式传输机制验证其有效性和可行性，研究成果对提高大规模三维虚拟场景传输和渲染的实时性具有重要应用价值。

中文关键词： 虚拟地理信息系统；三维模型简化；用户兴趣区域；预下载策略；自适应流传输

英文摘要： With the popularity of the Internet, WebGIS has been applied for visualizing and sharing geospatial information over the Internet. However, large-volume three-dimension (3D) virtual scene data remains a challenging issue in WebGIS applications due to its inherent complex structures and topological relationships. Additionally, the network speed can not keep up with the growth of spatial data, and it has become the limitation in data transmission. Streaming transmission has huge significance for solving the problem that large-volume 3D virtual scene transmission can't meet the need of customer timely. The related researches mainly focus on simplification of 3D models and multi-scale organization, but rarely on the scenes that user observed in a view point and the importance of three-dimensional objects over the Internet. This research presents the prefetching strategy based on area of interest and importance of 3D models, and discusses the following several problems: (1) The area of interest based on the attention of a user, the characteristics of 3D models and history trajectory of users; (2) The quantified model for the importance of 3D models, including geometrical characteristic, spatial distribution, textural features and topological relation et al.; (3) The simplification algorithms and streaming coding of 3D models based on visual characteristics suitable for this study (4) The transferring mechanisms of streaming transmission and the to integrate the Http adaptive streaming technology in the prototype system for data experiment. This project intends to verify the effectiveness and feasibility of streaming transmission mechanism using large-scale 3D terrain data and digital city data. These research results have important theoretical and practical value on improving the real-time of large-scale 3D scene transmission and rendering.

英文关键词： Virtual Geographical Information System;simplification of 3D models;area of interest;prefetching strategy;adaptive streaming transmission