topic Re: Export Points from DEM surface to Points File? in Civil 3D Forum

Export Points from DEM surface to Points File?

Daniel_Hinks — Thu, 07 Apr 2022 16:51:22 GMT

I'm trying to export XYZ points from DEM surfaces i created in Civil 3D using OSTerrian5 DTM data, so that i can import it into Recap to create a Point Cloud file .rcs and link it back into CAD as the file is too heavy with the DEM surfaces stored within the CAD file itself.

My workflow at the moment works but it's really long and tedious... Displaying the points on the surface and extracting these objects into AutoCAD points, ~~and then converting them into Civil 3D points, then exporting to a CSV file~~ (Edit: No need to convert the AutoCAD points, can use DX tool to export) ~~converting that to txt file to bring in to Recap.~~

Is there a better workflow? I tried the Export Surface points to CSV report but it crashes and I'm not sure that's the right tool for this anyway,

Re: Export Points from DEM surface to Points File?

Pointdump — Thu, 07 Apr 2022 17:48:00 GMT

Hi Daniel,
"Is there a better workflow?"
I don't think so with Civil 3D. I'd use LASTools, CloudCompare, or QGIS with the original data. In what file format is the original data?
Dave

Re: Export Points from DEM surface to Points File?

TerryDotson — Thu, 07 Apr 2022 23:15:38 GMT

I'm trying to export XYZ points from DEM surfaces i created in Civil 3D using OSTerrian5 DTM data, so that i can import it into Recap to create a Point Cloud file .rcs and link it back into CAD as the file is too heavy with the DEM surfaces stored within the CAD file itself.

Grab the DotSoft LidarTools Freeware either in a ZIP file from the DotSoft Blog, or with an installer from the Autodesk App Store. One of the tools is ...

LIDARMAKE

Create a LAZ file from Tin/Grid surfaces (classification 2 for ground). Includes a surface sampler that writes out points on a virtual grid (user supplies interval) draped onto the surface for reducing existing overly dense surfaces.

But unless you enjoy jumping through hoops there is no reason to involve ReCap. Simply use another one of the tools to make a Civil3D TinSurface ...

LIDARTIN

Prompts for a file selection of LAS/LAZ files, which classes to use (separate multiples with a comma), then a rectangular window for your area of interest. Any points in a file that fall outside the window are not included. Any files selected that fall outside the AOI are not even scanned for points (saved time).

Civil3D does all the calculations, surface elevation determinations and triangulation, we just automate the processes.