关键词: 场景管理, 实时绘制, 地下空间, 虚拟现实

Abstract: Large scale scene visualization is a challenge to Web3D virtual reality (VR) system. In the virtual urban simulation, apart from the buildings on the ground, the underground space visualization is also essential, because it includes many important components such as subway stations, car parks and underground utilities (e.g., pipelines and tunnels). This paper proposes a lightweight Web real-time rendering scheme for large scale underground space. Firstly, in order to organize the mass underground space data more efficiently, this paper proposes a lightweight scene ground structure. Then, this paper proposes an underground space scene management strategy based on progressive area of interest (PAOI). In order to optimize the rendering system with respect to data loading according to needs, the components of the outdoor structure are bounded on their corresponding grid. Alternatively, the interior space is represented as a connected graph. Using the proposed techniques, the memory consumption is apparently cut off. Meanwhile, the display content significantly increases. To verify the effectiveness of the proposed algorithms, this paper implements the prototype system using Flash 3D. Without any plug-in installation, the user experience is improved. The experiment shows that the proposed method has high performance and is suitable for large scale underground scene online rendering.

Key words: scene management, real-time rendering, underground space, virtual reality