Modeling And Rendering Of Large-scale And Realistic Spherical Ocean Based On Digital Planet

With the changing times, the virtual reality technology requirements are also increasing. 2D technology is gradually improved to 3D simulation technology; higher challenges against us are following, such as simulations of the natural scenery. Technology is changing from the ground virtual reality to the ocean virtual reality, even from the simple flat to a more realistic sphere. Basically 70% of the area of our earth is covered by oceans; ocean photorealistic rendering has always been the focus of research and difficult problems in the field of simulation and virtual reality. With the current computer hardware and software technology continues to innovation, requirements of the ocean virtual reality are becoming higher and harder. Real-time and realistic have became the research focus of modern marine simulation technology.Virtual reality simulation of the ocean has important significance in the development of marine fisheries and marine climate research, similarly broad role in the movie and game simulation and other commercial entertainment direction, even more special is its important application in the modern military operational command system. But now researches about ocean rendering are mostly concentrated in a small range of plane rendering, modeling and rendering techniques about the massive photorealistic ocean based on digital earth appear sporadic thin.Content of this research is modeling and rendering photorealistic massive spherical ocean based on digital planet. Our goal is to achieve a spherical ocean component of 3D digital planet which can be observed from multiple viewpoints. The main contents of this research are as follows:1. At first we will introduce the concept of Digital Earth and modeling about spherical terrain, then we will bring about a multi-resolution spherical grid, and using multi-resolution satellite photos on grid maps in order to achieve a digital planet.2. We study and learn the common modeling theory and rendering technology about ocean waves of nowadays; analyze and understand the pros and cons of each theory and the corresponding range. Then we carry out the ocean waves modeling for real-time simulation of wave fluctuations on the basis of the digital planet. We take the Perlin noise technology as a starting point to study and improve, so that we can break through the limitations of ocean wave modeling techniques on plane and draw a wave modeling which can apply to the digital sphere oceans.3. Upon completion of the geometric realistic modeling we try to figure out the modeling of optical realism. At first we go through the current mainstream research and introduce the main illumination model, understanding the principles of illumination model. Then we will achieve static mapping in long-distance ocean conditions, dynamic mapping and simple illumination simulation in middle-distance ocean conditions, as well as light refraction, light reflection, caustics and other effects in short-distance ocean conditions. We will simulate and draw a photorealistic ocean with different levels of detail.4. We introduce the system design platform and architecture of the ocean modeling and rendering, explore the theory and technology which has the worthy of further research.