A new method of virtual reality based on Unity3D

In the area of geographic information system, there are always two methods to get 3D virtual reality, one is to use a 2D professional platform such as ArcGIS software to get the virtual reality by secondary development, the other is to use a 3D or 2.5D software as a platform for development, such as the Skyline software. In this paper, we will use a different platform, Unity3D, which is usually treated as game development software, as a virtual reality development platform. Firstly, the hierarchical approach of geographic information system is adopted in the study area, and the area is divided into four layers: Terrain Layer, Building Layer, Transport Layer, Vegetation Layer, additionally, the raw data of Terrain Layer is obtained by GPS measurements. Secondly, all the geographical entities which related to different layers are converted to 3D model by AutoCAD and 3dsMax software. Thirdly, the 3D models are imported into the Unity3D, and programming with Javascript language in Visual Programming Language Editor in order to achieve Gameobjects and Scenes. Lastly, the Scenes are integrated and published on the network. The attribute data of study area is stored by MySQL which is connected with Unity game platform by external interface. Visitors can download the ActiveX control to browse the study area, the scene is keep on updating 60 times per second, the viewer will subconsciously input and immediately immersed in the virtual scene for spontaneous exploration and observation. With a full range of personalized mode of operation, the users can choose their own way to browse and participate in the virtual reality, and give full play to their imagination according to their own wishes without affecting the others by using the designated keys on the keyboard.