视景建模中树木纹理图像的随机变形网格方法  

Method of random transmogrification mesh for tree texture images in scene modeling

作　　者：施冠羽[1] 欧阳清[1] 

机构地区：[1]海军工程大学动力工程学院,武汉430033

出　　处：《中国图象图形学报》2015年第10期1384-1389,共6页Journal of Image and Graphics

摘　　要：目的视景建模中,采用"公告板"贴图法对同树种不同个体树建模时,需生成各种形态各异的树木纹理图像,为此提出一种新的生成树木纹理图像的随机变形网格方法。方法首先将树木的原始纹理图像进行网格划分,再对网格顶点进行随机变形,最后将生成的不规则网格中的图像映射到新图像中相应的规则网格上,得到变形后的纹理图像。结果应用随机参数控制树木图像的变形,模拟出成长环境因素对树木形态的影响。本文方法比采集多幅个体树图像贴图方法更简便,容易实现;比用同一幅图像进行多个个体贴图的视觉效果更真实。结论本文方法生成的树木纹理图像应用于"公告板"贴图时,在视景模型中能较好地模拟出同一树种的多个个体树情景。该方法基于图像的局部变形,仍然保持原始图像内容的整体基本形态和内部结构的连续性,因此,同样适用于其他不规则形状的自然景物(如山峦、河流、海浪等)的图像处理。Objective To address the problem of how to produce variform individual texture images of tree from the same tree species through the method of ＂bulletin board＂ mapping in scene modeling, a method to generate tree texture images through the use of a random transmogrification mesh is proposed. Method The original mesh is utilized to divide tree texture images. Then, random transmogrification of the mesh vertexes is conducted. Lastly, the generated irregular mesh images are nlapped on a corresponding regular mesh in the new images; texture images are obtained after transmogrification. The effects of mesh division quantity, transformative coefficient of the mesh, and quantity of mapping nodes on the transformative results are simulated. Result By selecting the mesh division number, transformative coefficient of the mesh, and quantity of mapping nodes appropriately, the original texture images of trees after transmogrification can be converted into mltiple ones that have similar basic forms but different details. Experimental results indicate clearly that the problem of texture image generation of different individual tree fi＇om the same species can be solved by the proposed method. The proposed method involves a stochastic parameter to control the local transmogrification extent of tree images ; the environmental impact on the individual form exerted by various random factors in their growing environment is reflected. The method is much easier and more convenient than individual tree image mapping. Additionally, the visual effects produced by this method are more real than those produced by mapping muhiple individuals in the same image. Conclusion A new method to generate tree texture images through the use of a random transmogrification mesh is proposed. The transmogrification extent of tree images is controlled by a stochastic parameter; the effects on the individual forms exerted by various random factors in their own growing environment are simulated. Images of individuals with various shapes in the same sp

关 键 词：视景建模 树木纹理图像 随机变形 树木形态 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]