Research On Generating Technique Of Special Effects And Surface Simplification Technique Of Object Models In Virtual Battlefield

Virtual battlefield has many particular advantages in the military maneuver, such as scientific, economical, antagonistic, intuitional, interactive, real-time, etc. And it provides an efficient approach to implement the scenario of stratagem, battle and tactic for all the armies in the world in the new age, and enhances the training effect for the participants. It is necessary to the virtual battlefield that a virtual battle natural environment should be realistic and be updated dynamically in real time. The generating technique of special effects and surface simplification technique of object models are the key to build such a virtual battle natural environment.In this dissertation, we study the generating technique of special effects and surface simplification technique of object models in the virtual battlefield. The main research and contributions of this dissertation are:(1) Real-time visualization of dynamic terrainIn the virtual battlefield scene, it is necessary to display craters on the ground due to the explosion of cannonball and legible tire tracks behind a moving vehicle. Both craters and tire tracks change either the elevation of terrain or the surface properties such as color, texture. Therefore, we called the technique to generate the craters and the tire tracks in real time as the technique of real-time visualization of dynamic terrain. The rendering of continuous LOD terrain surface is the key technique to build the virtual battlefield scene, and it is also the technical basis of generating the special effects such as craters, tire tracks.In this dissertation, the definition of an appropriate and validnested error metric sphere is presented, and a fast continuous LOD terrain rendering algorithm is proposed. And the nested error metric can eliminates the cracks in the meshes of the terrain surface automatically and implicitly. This algorithm is the technical basis of generating the special effects on the ground. Examples illustrate speediness and efficiency of the algorithm.To meet the special requirement in visualization of dynamic terrain, a technology which is called dynamically extending the resolution of terrain surface meshes is proposed based on the aforesaid fast continuous LOD terrain rendering algorithm. A theorem on the maximal region which needs to extend its resolution is given and proved. And the complete solution to visualize the dynamic terrain in real time is given. It both eliminates mesh discontinuities and represents the deformed region well in terrain model. Based on the complete solution, many kinds of special effects on the ground such as the realistic craters, tire tracks and trench can be generated in real time. Examples in this dissertation illustrate practicability and efficiency of the solution.(2) Modeling and real-time rendering of water columns which are generated by an underwater explosionIn a naval battle, after the underwater detonating of high-condensed explosives, grand water columns usually will come into being on the sea surface. Simulating realistically water columns' behavior in real time contributes greatly to the sense of reality of virtual naval battle environment.A method is proposed to simulate water columns' behavior generated by an underwater explosion. The physical phenomena of underwater explosion are analyzed, and the initial velocity equations and dynamics equations of water particles, which compose the water columns, are setup. For real-time requirement, each water particles cluster is rendered as a small circular area in a plane that faces the viewer, and this small area is texture-mapped with a pre-captured image of water particles cluster, with an intensity-based alpha channel. Examples illustrate that the method can meet the requirements of real time and reality.(3) Real-time simulation of the building shattering caused by the blast waveThe blast wave that generated by an explosion can destroy the objects badly such as the buildings. Realistic simulation of the shattering of the objects can enhance...