摘要
科学计算可视化是将错综复杂的海量数据转化为有组织结构的空间几何形状、颜色、纹理、动画等视觉信号并展示出来。该技术可以充分应用到对复杂物理环境和系统动态过程的模拟展示中,例如在计算流体力学、医学成像、地质勘探、气象等多个领域。本文以虚拟现实环境下的电磁场三维可视化作为研究目标,研究的主要内容包括电磁场数据可视化、复杂电磁现象可视化以及电磁空间环境可视化。
借助计算机图形学技术,对电磁环境、电磁现象进行视觉再现,可以为相关研究人员、指挥决策人员提供直观快捷的数据依据。电磁场可视化是一个综合性技术,需要充分考虑电磁场模拟数据类型的多样性、磁场物理环境复杂性等特点。Marching Cubes方法和Hedgehog方法分别是目前实现电磁标量场和矢量场可视化有效方法,本论文在实现该可视化算法基础上,结合实际应用,将电磁场可视化数据集及其相应的操作(映射、绘制等)以“对象”的形式加以抽象,构造了基于面向对象的电磁场数据可视化流水线模型。另一方面,在针对大范围地域电磁场环境交互式可视化问题上,采用八叉树结构对地形以及电磁数据进行空间分块和存储,并结合LOD调度技术,实现实时渲染。
进一步,在针对雷达扫描过程的模拟方面,结合余辉的产生、更新以及消失的动态特性,采用粒子系统,建立雷达扫描的余辉模型。该模拟的实现可以为飞行器低空飞行提供可视化的数据分析依据,还可以为飞行仿真建立一个可视化的虚拟环境。
最后,对电磁场所处的空间环境进行可视化,可以有效地分析地形等因素对电磁场变化的影响。本论文系统通过对电磁场所处的三维空间环境进行可视化,增加了系统的沉浸感,在虚拟现实的环境下,全面表现空间的电磁场分布等情况,能更好地帮助相关人员把握电磁场的本质规律等。
Visualization in Scientific Computing can convert large amounts of data into structured space geometry, color, texture, animation and other visual signals for displaying. This technology can be fully applied to demonstrate certain complexly physical environment and simulate system dynamic process, such as computational fluid dynamics, medical imaging, geological exploration, weather, and other fields. This paper researches the 3D visualization of electromagnetic field based on virtual reality environment and the main contents include electromagnetic data visualization, complex electromagnetic phenomena visualization, as well as electromagnetic space environment visualization.
By using computer graphics technology, the visual reproduction for some complex electromagnetic environment and electromagnetic phenomena can provide better data basis and help for some people's researching, decision-making and commanding. Electromagnetic field visualization is an integrated technology, for which we need to consider the type diversity of the electromagnetic data, the complexity of the magnetic field and other physical characteristics of the environment. We realize the scalar and vector visualization of electromagnetic field by using the Marching Cubes and Hedgehog modeling methods and establish, an electromagnetic data visualization pipeline mode based on object-oriented methods, through encapsulating the visualization data sets and corresponding operations (mapping, rendering, and others) as the target concept. On the other hand, in response to the interactive visualization for large scope of electromagnetic environment, we block and storage the electromagnetic data through octree structure. At the same time, making use of level of detail technology, we realize real-time rendering.
Further more, based on the basic dynamic generation, updating and disappear characteristics of afterglow, the idea of particle systems was proposed to represent afterglow model in radar scanning process simulation. The realization of this simulation can provide visual data analysis basis for low-flying aircraft and establish virtual environment for flight simulation visualization.
Through the visualization of the environment, we can analyze the changes in the electromagnetic which caused by some factors like the terrain effectively. In the 3D visualization system for the electromagnetic field, we consider and realize the space environment visualization in which electromagnetic field existing, including terrain, landform environment and so on. The effect of space environment visualization can consumedly enhance the immersion characteristic of system and fully demonstrate the distribution of the electromagnetic field in the virtual reality environment, which can provide better help for people grasping the nature of electromagnetic fields.
引文
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