AutoCAD Civil 3D

[#1]

I have DEM surface information that is all metric. I want to convert to imperial. I have changed the horizontal coordinate system to my local grid in feet, but I cannot figure out how to change the vertical surface from meters to feet. It should be a simple multiplication, but I cannot figure out how to perform any adjustment of the vertical elevations besides adding an offset.

[#2]

1. In drawing Toolspace
Settings > Drawing Settings > Units and Zone SETUP DRAWING COORDINATE SYSTEM ZONE AND UNITS

2.Settings > Surface Style

3.Prospector Tab
Surface > Create
Set Description
Set Style

4.Prospector Tab > Surfaces > Surface1 (+ EXPAND)
DEM > Add
Select DEM file (USGS ascii format)
Set CS Code
Set Null Elevation
OK

Note files in the DEM.SDTS.TARgz format can be converted to the USGS ascii format using MICRODEM (a free download from USNA)

Jim
MATRIX SURVEYS

[#3]

Thanks for your reply. This is a good description of how to import a DEM and convert the horizontal alignment. However, my problem is still the same. This process does not covert the vertical surface from meters to feet. The horizontal surface is correctly converted to feet, but the vertical remains in meters. BTW, the DEM I have is a GeoTIFF.

[#4]

CS (coordinate system code has to be set in lower window) DEM insert screen

DEM files are usually in UTM NAD 27 METERS need to know the Projection (NAD 27 or NAD 83) and the Zone)

Wizard only works in same projection. Have to fill in the Systems in the lower Window for a transform.

Jim

[#5]

This is interesting
When I create a new TIN surface, then set my GeoTIFF file as DEM input source, set the CS codes correctly and import, the horizontal projection is adjusted correctly, but it won't convert the vertical projection to feet. However, if I create a new Grid surface and select my GeoTIFF file as the DEM input source, I cannot select a CS code for the DEM file. I do notice that in the "DEM file information" area the coordinate system is being read from the file. When I go ahead and import the surface, the vertical is adjusted to feet, but the horizontal is not transformed.

PS
DEM files are not always in UTM NAD 27. I have to use what I have, which is Lat/Long NAD 83.

[#6]

Have you found a solution to this issue yet. I have run into the same problem, using the same data sources.

[#7]

No Autodesk solution. I found a program called Global Mapper that handles DEMs and images well, and it will convert meters to feet and change coordinate systems with little problem. It also merged and cropped my DEM. The only kicker is that it costs $350 to purchase. I haven't tried 2011 yet to see if they changed anything.

[#8]

Greetings!  In Civil3d 2011, I started to play with the point cloud to take the ddf files to create surface.  What I am curious to know is that the DEMs are in meters and I am looking to work in US feet...it would appear that if I have my drawing setup for the same zone and projection and I specify that the ddf are to be in the same format, does that mean that point clouding converts the meters into feet and places the file into the proper coordinate system?  I am not sure if I need to make any adjustments or where to begin to verify that the information is good and viable to use for preliminary project work.  Thanks!  PS I did go through the tutorial and this was not addressed. 

[#9]

I wrote a blog post on this topic a while back and I remember coming across an issue something like this. I believe the solution was to create a regular surface and add the DEM file to it. If you create a surface from a DEM file, things acted weird.

http://civil3dplus.wordpress.com/2010/02/02/using-dem-information-in-civil-3d/

[#10]

just a thought, what happens when i bring in the DEM in one dwg, then insert that dwg into a new dwg as a BLOCK, with a Z scale of 3.2808?