3D引擎中大规模海面实时渲染及场景管理研究与实现

发布时间：2018-03-22 17:19

本文选题：水面渲染　切入点：投影网格　出处：《电子科技大学》2009年硕士论文　论文类型：学位论文

【摘要】： 随着计算机软硬件技术的不断发展,三维图形引擎技术逐渐成为计算机图形学的主要研究内容之一。它在虚拟现实、数字城市、影视广告、计算机辅助设计和科学计算可视化等各个方面都发挥着巨大的作用。用计算机模拟自然界的各种自然现象是三维图形引擎中的关键技术。自然景物有着形态复杂,随机变化等特点,难以用确定的数学模型来表达和研究。与模拟火焰、云、山脉和雨水等自然现象相比,海面以其复杂的运动规则和光学特性使得对海面的模拟更加具有挑战性。对此,本文从国内外的研究现状出发,对海面的几何建模和光学建模进行深入研究,并在海面网格生成技术和大规模海面的场景管理上进行改进。从而给出大规模海面实时渲染的步骤和大规模海面场景管理的优化算法。在海面的几何建模方面,以现有的投影网格LOD算法为出发点,构造出限制采样精度的投影网格,此方法改进了旧的投影网格算法在视点离水面较近时采样频率陡增,采样点过密而导致水面网格不平滑的现象,能很好地与快速傅立叶变换(FFT)算法生成的水面相结合。同时该算法也在一定程度下减少了投影网格的三角形面片数,提高了渲染效率。在海面高度场的生成方面,本文对各种文献资料进行深入分析研究之后,运用海洋统计学公式模拟出复杂的海面起伏的效果。并且这种统计海波算法可以表示为FFT的形式。因此,采用这种算法,可以快速的将各种不同频率的波混合叠加在一起,产生具有更加复杂行为的波,这样就可以模拟出非常逼真的海面效果。在光学建模方面,本文改进了HDR算法和基于纹理动画的Normal Mapping算法,并提出了将多种光学效果融合的计算公式,提高了海面的光效真实感。在大规模海面场景的管理方面,通过对渲染流程的改进,实现了对海面场景管理的特殊性要求。可以对海面、海底场景进行正确的裁减,减少不必要的渲染,提高渲染速度。此外,通过在原创的三维图形引擎中将上述算法实现,得到了相应的实验结果。应用证明上述算法很好地满足了虚拟海面的实时漫游的需要。最后,对海面实时渲染的算法进行小结,并提出了改进建议以及进一步的展望。
[Abstract]:With the continuous development of computer hardware and software technology, 3D graphics engine technology has gradually become one of the main research content of computer graphics. It in virtual reality, digital city, television advertising, various computer aided design and scientific visualization plays huge role. With the computer simulation of natural phenomena is the key technology of 3D graphics engine. Natural scenes have complex shapes, random variation characteristics, difficult to express and study with the mathematical model. And the simulation of the flame, cloud, rain and other natural mountains and compared to the phenomenon, the sea movement rules of complex optical properties and makes simulation of the ocean is more challenging.
In this regard, this paper studies the current situation at home and abroad, in-depth study on geometric modeling and optical modeling of the sea, and improve the scene management of ocean surface grid generation technology and large scale on the sea. The optimization algorithm for large scale ocean rendering steps and large-scale sea surface which gives the scene management.
In geometric modeling of sea surface, with projected grid current LOD algorithm as the starting point, to construct the limit projection grid sampling accuracy, this method improves the algorithm in the old view close to water surface when the sampling frequency is increased sharply, the density of sample points due to surface mesh unsmooth, well with fast Fu Liye transform (FFT) algorithm to generate the surface combination. At the same time the algorithm has to a certain extent reduce the triangles projection of the grid, improve the rendering efficiency.
In the generation of the sea surface height, after the in-depth analysis and research of various documents, the use of marine statistic formula to simulate the complex effect ofshifting. And this formula can be expressed as the form of FFT. Therefore, using this algorithm can fast wave superposition of different frequency mixed together, to generate more complex behavior wave, this can simulate more realistic surface effect.
In terms of optical modeling, this paper improves HDR algorithm and Normal Mapping algorithm based on texture animation, and proposes a formula to integrate multiple optical effects to improve the effectiveness of sea surface.
In the management of large-scale sea scene, through the improvement of rendering process, we have realized the special requirement of sea scene management. We can correctly cut down the sea surface and submarine scenes, reduce unnecessary rendering and improve rendering speed.
In addition, through the implementation of the above algorithm in the original 3D graphics engine, we get the corresponding experimental results. The application proves that the algorithm can well satisfy the need of real-time roaming of virtual sea surface.
Finally, the algorithm for real-time rendering of the sea surface is summarized, and the suggestions for improvement and further prospect are put forward.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：TP391.41

【引证文献】