地形数字高程模型的物理模型快速成形方法

Rapid Prototyping of Terrain Physical Model Based on Digital Elevation Model Data

地形物理模型被广泛应用于城市建设、军事战略规划、流域和地质教育等方面,而目前数字地形模型多以数字高程模型数据格式进行存储和显示,为此提出一种将地形的数字高程模型数据直接转换成三维STL模型文件进行快速原型制作的方法.首先对多种格式的数字高程模型数据进行识别转换,根据预设比例和打印精度进行数据简化处理;然后将地形表面数据转换为三角面片,并根据预设阈值进行面片优化和误差修正;最后补充基底和侧壁的三角面片,生成三维STL模型文件,下载到快速成形系统中制作出缩放后的地形物理模型.选取地理特征明显的采样区域进行地形物理模型快速成形实验的结果表明,该方法可以省去中间转换过程,有效减少数据丢失,用更少的时间和更低的成本创建出地形物理模型.

The terrain physical models are widely used in urban planning, military strategy planning, water-shed and geological education, etc. However, current terrain models are mostly stored and displayed by us-ing digital elevation model (DEM) file formats. A method is presented to directly convert the DEM file of a terrain model to the 3D STL Model, which can be processed and fabricated by rapid prototyping (RP) sys-tems. Firstly, various formats of the DEM data are identified and simplified according to the scale and reso-lution. Secondly, the surface of the terrain is converted to the triangular facets, which are optimized and corrected based on the preset threshold. Finally, the STL model is constructed by adding the base and walls, from which the terrain physical model can be fabricated by a RP machine. A terrain sample with typical to-pographic feature is selected for analysis. The experimental results demonstrate that the intermediate proc-esses of data conversion are eliminated and the volume of model data is reduced effectively. Furthermore, terrain physical models can be fabricated by RP system in less time and less cost.