First time Civil3D user. I'm trying to put together a SIMPLE road design project for a CE453 geometric design class (data->surface->alignemnt->profile->crosssection->cut/fill->plans).
I went here (http://data.geocomm.com/catalog/US/61087/2366/group4-3.html) and downloaded the two portions of the county that where my project is located. The two tar.gzs came as a bunch of DDF files and I used this (http://data.geocomm.com/dem/sdts2dem.html) to combine the DDF files into a DEM. Since I had two sections, I ended up with two DEMs.
I opened Civil 3D and added two surfaces (created from each DEM), but I only need a small section shown in the rectangle in the picture. How can I reduce my surfaces to this area?
Also, am I even close to doing this right? I've used (unfortunately) EaglePoint and Carlson in the past. I wish I would have just learned Civil3D, but now I'm stuck Googling how to find free surface data and use this daunting 4GB program and teach it 😕
Thx for the help!
You can add a vector boundary to the surface definition, then export the subset to a new smaller Dem.
Read the help file about Data Clip boundaries. A data clip boundary can be added to a surface BEFORE you add any data, so unlike a normal boundary, it actually reduces the extents of the data that has to be processed.
I'm assuming you would have to add the data clip boundary to area of need (coordinately correct) before a .dem file was brought in....correct??
To do this, i would need to bring in a USGS quad or turn on Bing mapping via Geolocation tool to add my data clip boundary in area of need before I bring .dem file in.
Those methods can be used to determine the extents of the clip but there are other mjethods as well (i.e. inquire a LAT/LONG or NorthEast from a web map, a parcel overlay, etc. You can also build a point cloud and display it to determine the extents of the data, then draw the clip boundary within the extents. Any method will do.