So here is my scenario. The crew has ran a profile on a proposed line. I am then given lidar data to compare to. I can create a surface from the ground points in the lidar data. I was hoping to run a report that would compare all the points the crew shot vs. the dtm from the lidar data. Basically a cut fill data. The points were not shot in as-built mode nor will the be in the future. So that option is out the window. I know I could do it in ARCGIS but I would like to keep it in TBC or C3D.Any suggestions? I know I could do it in ARCGIS and do raster math, but I would like to keep it in TBC or C3D. Any Suggestions?
Can't you import the LAS into C3D as a Point Cloud Object and extract a surface from it? I did something like that once about 6 months ago with C3D 2014.
One thought (but maybe not the most streamlined process). Create points using the lidar surface at the surveyed points location, you could then export both sets of points to a spreadsheet to make a comparison.
I'm not sure the problem. I'm pretty sure you can compare two surfaces and have it show the differences between the surfaces in C3D. Maybe the problem is you have a single line profile and can't make a surface? I'd just copy the points over and make a double row of them that way you can make a surface, even though its really just a single line of points.
I guess I could do that create a mini dtm but. What I was hoping to do is input a point file and output a file that shows point# n,e,elev,cut/fill(to the surface), code then I could sort by code or cut fill and look at large data sets quickly in a exel format.
Yes I can create the surface from the point cloud.
Not that this does you much good but you can do what your asking in about 15 seconds with the Sincpac Civil3d addon. Vanilla Civil3d will require you do create a work around.
We do exactly what your describing quite often.
If you know how to make a profile then create an alignment along the poly line of the located points but using the lidar surface make a profile.
Then create a surface with just the located points and using the same poly create an alignment and a profile of that surface, change the color of the located profile line and copy just the top line over the lidar line.
Since they use the same exact location and base elevation it will just be a copy paste
Bingo-two lines comparing the data sets. There is at least one more way to do this, but its a bit more complicated.
I think this little lsp may just do the trick.
http://forums.autodesk.com/t5/autocad-civil-3d-general/cut-fill-report-for-point-group-to-surface/td-p/5108234
With a little bit of modification this will be just what I need.
I have done this in Global Mapper with both terrestrial Lidar and aerial Lidar. You bring in the las file, and then the profile points. I think I had to interpolate elevations in GM for the profile points on the surface created from the las file, and then I compared the elevations in excel after exporting. It has been a while, but that is the general process I used as I recall.
I have Sincpac 1 and 2. What is the command/drop down to generate this report?
I created a surface based in the lidar ground points. Tweaked the lisp routine from the link I posted above. It ceates ask you to select the surface and then the points you want to compare to the surface. If you select the point group before running the lisp routine alls I have to do is select the surface. Right now I have it outputting a txt file that is $ deliminated with the Point Number, Code, Pt Elev, Surface Elev, and the surface difference. That makes it real easy to load in excel and sort by differences and then codes so I can compare diffrences. Im not sure what it will do where we have gaps in lidar data just yet because I just created a quick surface from all the points.
> I have Sincpac 1 and 2. What is the command/drop down to generate this report?
Since our 2015 upgrade we haven't upgraded sincpac and won't until March. If i recall its under the analysis tab and its Display Surface/profile. Once there you can compare points to profiles and/or surface and export any type of report you want.
