基于对数映射的三维路面高程晕渲技术研究

Study on elevation shading technique of three-dimensional pavement based on logarithmic mapping

采用传统的基于线性高程晕渲方法重建的三维路面,对于较平整的路段,显示的路面效果比较夸张,而对于路面质量较差的路段,在显示坑槽的同时,又会忽略路段的平整特性。提出一种基于对数映射的三维路面高程晕渲方法,首先以路面平均高度值为基准将测得的路面相对高程归一化,再将归一化后的高程进行对数映射,最后将变换后的数据线性等分成20个晕渲色层。在-10^+10mm的相对高程范围内对应于10个色层,表征路面的平整特性,-10^-100mm和+10^+100mm的相对高程对应于另外10个色层,用于表征路面的变形类病害。研究结果表明:运用这种方法不仅能够实现对路面质量较差、路面有较大坑槽和拥包的三维路面的彩色晕渲,同时还能表现路面的破损信息、局部平整度及车辙信息,增强了显示效果。

For the reconstruction of three-dimensional pavement by using the traditional method based on linear elevation shading,the effect of display is exaggerated on the relatively flat road,but on the road of poor quality,potholes are displayed and the flatness of the road is ignored.Therefore,a kind of method of three-dimensional pavement elevation shading based on logarithmic mapping was put forward.Firstly,the raw data was normalized based on the average height,then the normalized relative altitude was logarithmically mapped,and finally the transformed data were linearly divided into 20 dizzy color layers.The relative elevation from-10 mm to 10 mm was divided into 10 color layers to display the flatness of road,while the relative elevation from-10to-100 mm and from ＋10to ＋100mm was divided into other 10 color layers to display the deformation distress.The results show that it can not only realize color shading for the poor quality road with big potholes and upheavals,but also reflect damageinformation of road,partial flatness and rut information.The effect of display is enhanced.1tab,11 figs,10refs.