基于动态纹理的太阳活动视景模拟方法研究

发布时间：2018-04-20 17:43

本文选题：太阳活动 + 耀斑　；参考：《中国科学院研究生院(空间科学与应用研究中心)》2015年硕士论文

【摘要】：太阳活动是太阳发射出的太阳辐射在总量上的变化,其组成具有周期性的变化特性,主要活动形式有太阳黑子、光斑、谱斑、耀斑、日珥和日冕瞬变等。剧烈太阳活动释放出的高能太阳风结构可能会诱发极光、磁暴、电离层暴等,这将对通信、电力的安全运行产生重大影响,也会对航天航空探索产生深远的影响。由于空间科学数据量巨大以及三维绘制的性能限制,近些年来对太阳活动视景模拟的技术不足够成熟,对其模拟的效果会出现各种各样的问题,比如绘制速度慢、用户交互性差、效果差,无法实现实时等。纹理在现实世界中普遍存在,是一种能够表现物体表面特征的视觉现象。在计算机图形图像学、计算机视觉、虚拟现实等研究方向,纹理常用于显示曲面几何形状。对于太阳表面的变化情况,可以用“纹理”来模拟。动态纹理是一种基于纹理映射的表示方法,是用来描述某种具有时间相关重复特征的动态景观的图像序列,比如随风而动的旗帜、瀑布、麦浪、烟雾等。元胞自动机是一种可以实现整体或局部随时间推移变化的动力学系统,该系统中的元胞按照一定局部规则在离散的时间维上演化。本文把动态纹理的合成技术应用到太阳活动的视景模拟方面。通过采用基于纹理块的样图纹理合成方法建立太阳表面静态纹理,实现太阳表面背景纹理的合成;通过把元胞自动机的演化规则应用到太阳活动中的耀斑,对其耀斑的大小和亮度变化进行仿真,最后在三维场景中实现整个演变过程。本文的创新点在于:1.将动态纹理合成技术应用到太阳活动视景模拟方面;2.利用QTM算法解决球面纹理映射过程中的极点汇聚问题;3.将太阳活动分为非活动区域和耀斑区域,分别定义元胞自动机的演化规则,应用到耀斑的爆发和消失,以实现太阳表面的动态演化;通过动态纹理对太阳活动进行视景模拟,在保证视景模拟效果的前提下减少计算时间,实现了对太阳活动的实时视景模拟。
[Abstract]:Solar activity is the change of the total amount of solar radiation emitted by the sun. Its composition has periodic variation characteristics. The main active forms are sunspot, spot, speckle, flare, prominence and coronal transient, etc. The structure of high-energy solar wind released by intense solar activity may induce aurora, magnetic storms, ionospheric storms, etc. This will have a significant impact on the safe operation of communication and power, and will also have a far-reaching impact on aerospace exploration. Because of the huge amount of space science data and the performance limitation of 3D rendering, in recent years, the technology of simulation of solar activity scene is not mature enough, and the simulation effect will appear various problems, such as slow rendering speed. The user interactivity is poor, the effect is bad, cannot realize the real-time and so on. Texture is ubiquitous in the real world, and it is a visual phenomenon that can represent the surface features of objects. In the fields of computer graphics, computer vision and virtual reality, textures are often used to display geometric shapes of surfaces. Changes in the surface of the sun can be simulated by "textures". Dynamic texture is a representation method based on texture mapping, which is used to describe the image sequence of a dynamic landscape with time-dependent repetition characteristics, such as flag moving with the wind, waterfall, wheat wave, smoke and so on. Cellular automata (CA) is a dynamic system which can realize global or local changes with time. The cellular in the system evolves in discrete time dimension according to certain local rules. In this paper, the dynamic texture synthesis technique is applied to the scene simulation of solar activity. The static texture of the solar surface is established by using texture block based texture synthesis method, and the background texture of the solar surface is synthesized, and the evolution rule of cellular automata is applied to the solar flare. The size and brightness of the flares are simulated, and the whole evolution process is realized in the 3D scene. The innovation of this paper lies in 1: 1. The dynamic texture synthesis technique is applied to the simulation of solar motion scene. QTM algorithm is used to solve the pole convergence problem in the process of spherical texture mapping. The solar activity is divided into inactive regions and flare regions, and the evolution rules of cellular automata are defined, which are applied to the eruption and disappearance of flare to realize the dynamic evolution of the solar surface, and the scene simulation of solar activity is carried out through dynamic texture. On the premise of guaranteeing the visual simulation effect, the calculation time is reduced, and the real-time scene simulation of solar activity is realized.
【学位授予单位】：中国科学院研究生院(空间科学与应用研究中心)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P182.9;TP391.41

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