Web3D-Based Online Walkthrough of Large-Scale Underground Scenes

Large-scale scenes' processing has become the major trend today. We mainly address the online walkthrough of Large-scale underground (UG) scenes in this paper. Taking into account the characteristics of UG scene, we first propose a lightweight preprocessing to optimize the raw UG scene and unify the raw data with scene, sub-scene and simple model. Then we generate a three-layered grid structure for organizing the scene to facilitate the visibility culling and data accessing. Finally, we design two scene management strategies, named SOI-Exterior Shell and Portal-Interior Shell, and integrate our methods in an experimental prototype. The experimental result shows that our method can remove a large amount of redundancies from the raw data, reduce resource consumption greatly and make it possible to walkthrough in large-scale UG scenes online without any web browsers plugins.