自然现象模拟是计算机图形学中的一个重要研究热点.如何快速、逼真地模拟自然现象是此类研究的主要目的.传统的解决思路大多采用基于物理的建模方法,而随着采集设备的快速发展,基于采集图像的重建方法得到了广泛关注与研究.以液体为研究对象,总结了近年来基于采集图像的重建方法的部分研究成果.针对动态水面,提出了一种动态水面数据采集与重建方法.首先,设计并搭建一套基于多相机的动态水面数据采集系统,采集得到多视图下不同水面运动现象的连续帧图像.其次,通过提取采集图像序列中每幅图像的亚像素级特征点,进行特征点匹配并建立特征点与物理空间中三维点的映射关系.然后,结合水介质的光学折射特性迭代求解水面上三维点阵的高度场和法向量.最终获得动态水面的重建结果.实验结果表明,该方法能够快速生成与采集水面可视效果相近的三维重建结果,可在计算机游戏、医学、科学研究可视化等领域具有应用前景.
Natural phenomena simulation is an important research area in computer graphics domain. How to obtain realistic natural phenomena by simulation in an efficient way is the main purpose of this research field. The physics-based modeling method is a traditional way to solve this kind of problem. Along with rapid development of acquisition devices, the image-based method attracts a lot of research attention and interest. This paper chooses liquid as research object. Main research achievements on the topic of image-based reconstruction are summarized. Focusing on dynamic water surface, a method of dynamic water surface data acquisition and reconstruction is proposed. First, a dynamic water surface data acquisition system is designed and built in order to obtain image sequences of different water surface phenomenon on multi-viewpoint. Next, feature points on each captured images in sequences are extracted. Then after feature point matching process, the mapping relationship between feature points and 3D points are built. Finally, dynamic water surface reconstruction results are obtained by using the height field and normal of 3D point combined with the optical refractive property of water. Experimental results show that this method can generate 3D reconstruction results rapidly. Satisfactory visual effect is also achieved facilitating this application to be used in computer games, visualization in scientific computing, and virtual simulation in medical area.