Civil 3D TIN to DEM Export

[Anonymous]

Hi

I was trying to export a simple TIN surface to DEM format for HEC-RAS inputs. Please refer to image 1 and 2 for the TIN surface and export procedure.

After the export procedure, I opened a new c3d file and created a surface based on the DEM. It seems like some points have gone missing (batter) while other points are still there (four columns). Please refer to image 4 for details. 

Could anyone help me to point out where did I go wrong with this? Thanks.  

Regards

Ryan

[Pointdump]

Ryan,
"...export a simple TIN surface to DEM format..."
What format did you use? GeoTiff? The USGS DEM format spits things out in integers, so that might explain why you didn't get the batters.
Dave

[Anonymous]

Hi Dave

Thanks for your reply. I just went to the prospector, right clicked the TIN surface then went to 'Export Surface to DEM'. The file format is .dem, so I'm not sure if it is geotiff or USGS DEM...

I tried this method before. From memory, it worked well - it spat out a surface that aligns with my TIN surface. Is this a typical issue when we export TIN to DEM? If so, can we export it to geotiff or other formats that HECRAS can read? Thanks.

Ryan 

[Pointdump · Accepted solution]

Ryan,
Does your exported file have a ".TIF" ending?

Dave

[Anonymous]

Thanks Dave. It solved the problem.