.3 D Engine In The Large-scale Sea Level Real-time Rendering And Scene Management And Realization

With the development of computer software and hardware, the technique of 3D graphic engine becomes a hotspot in CG research gradually. It plays an important role in virtual reality, digital city, advertisement and entertainment, CAD, realiztion of scientific calculation and many other fields. Simulation of natural phenomena by computer is a key technology in 3D graphic engine. Natural phenomena has the characristics of morphological complexity and random variation, which can not be expressed or researched by certain mathematical models. In particular, compared with simulating the natural phenomena of fire, clouds, mountains and rains, simulation of ocean is more challenging because of the complex motion rules and optical properties.In this paper, we discuss from the current research both at home and abroad, to give an in-depth study on geometric modeling and optical modeling of the ocean. Then we improve the technology of ocean mesh gerneration and scene management of ocean in large scale. As a result, we achieve the process of ocean rendering and optimized algorithm of scene management.In research of Geometric modeling of ocean, starting with exsiting project mesh LOD algorithm, we build a mesh with constraint sampling accuracy. Previous algorithm can drastically increase the frequency of sampling and the density of sample points when looking close to water surface, which will cause water surface mesh unsmooth. The new algorithm can solve this problem and integrate water surface generated by FFT algorithm (an ocean height field generation algorithm) very well. The algorithm can reduce the triangles of projected grid as well to enhance the efficiency of rendering.In research of ocean height filed gerneration, after an in-depth analysis of reference materials, we can apply ocean statistic formula to simulate the complex effect of shifting. And this formula can be expressed in form of FFT. So through this approach, waves with different frequency can be mixed together to generate more complecated waves, and thereby simulating more realistic pictures.In research of large scale ocean scene management, we can achive special requirments through improvement of render queue. We can clip scene over or under the sea correctly, and reduce unnecessary triangles to improve the speed of rendering.Futhurmore, an application of this algorithm mentioned above is achived in an original 3D game engine. The application proved that this algorithm can meet requirements of wanderings virtual ocean in real time.Finally, a conclusion and a perspective of ocean simulation are given.