I got two layer - one GeoTiff with DTM from Lidar data, the other is a shape file or another surface layer. I want to compare them (in ArcGIS or QGIS) you find procedures like "cut and fill" - in the end you got a summary of shapes and their volumes (positive = fills, negative = cuts). I need this for a couple of projects in my job - plan a road and calculate the bilance of the material or compare Lidar data for change detection. (I hope my English isn't to bad.)
Thank you!
I've done this (and presented on it during the FME Days in Essen last year, presentation should be online somewhere I think). Basically what I did was create a 2d grid of points and drape that over both surfaces using SurfaceDrapers, so for each point I have 2 z-values. Then from the difference in those z-values and the cell size you can calculate the volume difference. It's an approximation, the smaller your grid cells are the more accurate the result it (but the longer it takes).
Hope this helps.
I've done this (and presented on it during the FME Days in Essen last year, presentation should be online somewhere I think). Basically what I did was create a 2d grid of points and drape that over both surfaces using SurfaceDrapers, so for each point I have 2 z-values. Then from the difference in those z-values and the cell size you can calculate the volume difference. It's an approximation, the smaller your grid cells are the more accurate the result it (but the longer it takes).
Hope this helps.