Virtual Navigation In Digital City

The concept of "Digital Earth" is put forward during the course of information technology's development and application, Digital City is the crucial node that implements Digital Earth. Virtual Navigation is the specific application of virtual reality technology under Digital City construction, it is also a important problem in Digital City research. Virtual Navigation is to extend the function of Digital City, raise its practicality, rich its theories.This paper takes "Digital North West University" as example, to research the realization of Virtual navigation in Digital City. Major content is as follows: First, it has analyzed the corresponding basic theories and crucial technology of using, mainly include the establishment and retrieval of spatial database, technology of Virtual Reality, JAVA and ASP.Second, it has been completed Virtual Navigation in "Digital North West University" according to actual conditions of North West University. Retrieval spatial database by using the position of two point specified by user, complete the navigation automatically; Tracing and real-time display user current location depending on navigation map; Accomplish the query based on spatial relationship and property feature.Finally, devise the algorithm of optimum path. The algorithm makes use of the node-arc structure of graph and depth-first-search, have realized the retrieval of optimum path in virtual navigation. According to algorithm in system application, prove that it can raise intelligentance and the speed of optimum path retrieval. Virtual reality in Digital City strengthened the interaction with user, made the relation closer between geographic entity's spatial and non-spatial property. It has great theory and practice significance in Digital City's research. The resolvent to this problem supplied theories basis and technical support for the intellectualized virtual navigation based on the web, also accumulated experience for the realizing of 3D City.