Continuous Lod Terrain Simulation

As an "operational lab", warfare simulations that have been widely used in the domains of military training, warfare research, equipment development, and so on, present a promising future. However, modern warfare simulations, in terms of simulation model and animation, have high technical requirements for three-dimensional terrain environment. Therefore, studying the simulation of three-dimensional terrain environment in the field of warfare simulation is highly valuable for academic study and application.Based on bringing forward a general framework for terrain environment simulation system, furthermore, with the specific background of "armored vehicle combat simulation", this thesis simplifies the general framework.Real-time visualization of terrain is the key technology of the terrain environment simulation, and also the key point of this thesis. Through advanced studies on the continuous level of detail (LOD), which is a popular method to visualize terrain, the thesis improves a real-time continuous LOD algorithm for terrain based on GRID data. The algorithm generates three-dimensional terrain model and displays in real time. It uses an efficient and simple method to attain the dependency between sampling points on terrain, and refines the center points in top-down way. It incorporates the dependency of points into their errors so that the cracks inside the terrain block are avoided, at the same time eliminates the cracks at the edges of blocks through adjusting the elevations of those points that cause the cracks. The features of the algorithm about using frame-coherence and view-dependency are discussed in the thesis.A terrain flythrough prototype system is designed and implemented in this thesis, which has the simplified framework of terrain environment simulation system, and uses the real-time continuous algorithm above as the core. Proved by experiments, the continuous LOD algorithm is highly efficient, and the prototype system makes an interactive flythrough on a three-dimensional terrain scene, and lays a firm groundwork for the final realization of the terrain environment simulation system.