流域地理景观生成中纹理映射技术

洪水演进仿真系统的研制是进行“数字流域”工程建设的重要研究内容,系统的研制必须利用先进的模拟仿真与可视化方法等现代计算机技术,在计算机生成的虚拟环境中,对洪水在现实河道里的推进情况以及洪水对流域内区域的淹没情况进行仿真模拟。系统的可视化以流域地形的仿真为基础,流域三维景观的生成则是洪水演进仿真系统的主要可视化需求,纹理映射技术是实现流域三维景观的重要技术手段。在分析比较计算机图形学中的几种典型纹理映射方法基础上,针对复杂流域地形貌和卫星遥感流域数据源特点,研究了相应的纹理映射算法模型。使用Visual C 系统开发语言,依据清江流域的真实数据源生成清江流域三维网格地形,并基于OpenGl技术,运用逆透视过程和非参数映射方法,实现了清江流域三维景观的真实纹理粘贴,使生成的流域景观具有真实自然的三维可视化效果。

STUDY ON TEXTURE MAPPING IN VALLEY GEOGRAPHIC SIGHT REALIZATION

The development of flood routing simulation system is an important component of digital valley study.The flood boost in stream channel and flood inundation at valley's area can then be simulated under virtual environment on the basis of advanced computer technology such as simulation and visualization. Visualization of the system is based on the simulation of valley's terrain,and valley's three-dimensional sight realization is the important visual demand in flood routing simulation system. Texture mapping is an important method to realize valley three-dimensional sight. Analyzing and comparing several texture mapping methods in computer graphics, the system studies arithmetic model of texture mapping according to complicated valley terrain and physiognomy and its remote sensing data features. Selecting Visual C++, a system development language and OpenGL technology, using inverse perspective and non-parameter mapping approach, this paper realizes the texture sticking of QingJiang River sight on the already-built three-dimensional mesh terrain on the basis of QingJiang River's real data, achieves the natural and real three-dimensional visual effect in valley sight.