基于三维虚拟环境的林分结构调整可视化模拟技术

[目的]以真实林分三维场景为模型,结合计算机虚拟现实技术,实现对真实林分结构的调整优化可视化模拟。[方法]以湖南攸县黄丰桥国有林场杉木与鹅掌楸人工混交林为研究对象,采用可视化模拟技术,基于三维虚拟环境建立林分结构调整可视化模拟系统,实现对林分结构的优化调整进行可视化模拟。通过对林分的角尺度、大小比、混交度、开阔比等结构的计算分析,结合公告板显示技术和射线查询算法,在MOGRE构建的林分三维场景中对林分结构调整过程进行可视化模拟。[结果]样地林分结构经过调整后,平均树高由12.8 m变成13.6 m,平均胸径由17.1 cm变成18.6 cm;林分平均角尺度由0.449变为0.481,分布格局由调整前的均匀分布变成随机分布;林分平均大小比由0.511变为0.519,样地内林木生长更具有优势;林分平均混交度由0.093变为0.129,林分结构更加稳定,林分的整体质量也得到了提高。[结论]本研究采用可视化模拟技术和样地调查数据,构建虚拟三维森林环境,在三维场景中,森林经营者不仅能查看样地中每株林木构筑性属性,观察林分样地的整体状态,还能对林分结构进行优化调整,实现在虚拟森林环境中对样地林分结构调整进行可视化模拟。

Visualization Simulation Technique of Stand Structure Adjustment Based on 3D Virtual Environment

[Objective] To realize optimal visual adjustment of real stand structure based on the modeling of 3D stand scenes, which adopt the technology of visual simulation. [Methods] Taking the Cunninghamia lanceolata and Liriodendron chinense mixed plantation planted in the Huangfengqiao State-owned Forest Farm, Youxian County, Hu''nan Province were used as samples, the virtual simulation adjustment system was developed by virtual simulation technique, based on the 3D virtual environment. By calculating and analysis of stand angle scale, size ratio, mingling, open index and competition index, the simulated process of adjustment the stand structure in 3D stand scene based on the bulletin board display technology, ray query algorithm and MOGRE, was implemented. [Results] After adjustment of the stand, the average heights of tree changed from 12.8 m to 13.6 m, DBH changed from 17.1 cm to 18.6 cm; the average angle scale from 0.449 to 0.481. The distribution pattern of the stand changed to random pattern from average one. The growth of the stand had a huge advantage as the average size of the stand became 0.519 from 0.511. The average mixture degree of the stand changed to 0.129. After apply the adjusted methods, the stand structure became more stable, the quality of the stand improved a lot. [Conclusion] The visual simulate technology and field investigation data were applied to from the virtual 3D forestry environment. In the 3D scenes, forest managers can not only view the property of every single tree in the stand, but also be able to observe the whole state of the stand. The optimal adjustment of stand structure in virtual forest environment is realized.