Virtual Huanghe River System: Framework and technology.

Virtual Reality provides a new approach for geographical research. In this paper, a framework of the Virtual Huanghe (Yellow) River System was first presented from the view of technology, which included five main modules—data sources, 3D simulation terrain database, 3D simulation model database, 3D simulation implementation and application system. Then the key technologies of constructing Virtual Huanghe River System were discussed in detail: 1) OpenGL technology, the 3D graphics developing instrument, was employed in Virtual Huanghe River System to realize the function of dynamic real-time navigation. 2) MO and OpenGL technologies were used to make the mutual response between 3D scene and 2D electronic map available, which made use of the advantages of both 3D scene and 2D electronic map, with the macroscopic view, integrality and conciseness of 2D electronic map combined with the locality, reality and visualization of 3D scene. At the same time the disadvantages of abstract and ambiguity of 2D electronic map and the direction losing of virtual navigation in 3D scene were overcome. [ABSTRACT FROM AUTHOR]