USGS NED import failure

[andrewxgoodman]

Max's import function is not working with a NED download from the USGS. It reports 0 surfaces. Any suggestions on how to import data from USGS? I've attached a screenshot of the import screen and the USGS NED zip.

[Ernest Burden III]

I know I got the vertical scale correct--but I'm not sure of the horizontal. Usually the grid id either 10m or 30m, so I have it at 30m. Verify that size. The source file is in meters (even though the file is California) and so is the DXF.http://www.oreally.com/temp2/NED_97599270-DXF.zip

 

I used a GIS program to save out as a DEM and loaded that in Cinema4D, exported as DXF. The maps are screengrabs from the GIS software GlobalMapper

 

I don't remember seeing that filetype before. The USGS has come up with some weird files.

Edited March 31, 2010 by Ernest Burden

[andrewxgoodman]

Alas, I don't have a GIS program, or Cinema4d. I was hoping to use public domain data and programs to grab elevation data. It seems the USGS went off in a direction and no one followed.

[Ernest Burden III]

There are freeware converters and free 'lite' versions of some of the GIS stuff. But in the end, I found them so hard to work with and get good results that I just bought GlobalMapper. The time it saves me on even a single project with large land area makes it worth every penny.

 

You might also look for a converter from the NED thing into a DEM.

 

Max can't open a DEM, or it can?

[andrewxgoodman]

After following many blind alleys, I worked out a solution.

 

1) Identify the terrain rectangle you want. Use Google Earth, Get the Lat/Lon of the lower left and upper right corners.

 

2) Go to the USGS National Map Seamless Server. Pull height data for the rectangle itentified by the lat/lon bounds. Modify the output format from the default NED to the older GeoTiff format.

 

3) Use the program 3DEM to convert the GeoTiff file to DEM format.

 

4) I purchased a wonderful modestly priced plug-in, GroundWiz, earlier. GroundWiz includes an import module for DEM and Terragen files. I suspect the importer is included with the free demo version. I used the the DEM importer, simplifying the mesh in the process.

 

5) I next wanted to project a satellite image onto the terrain. First attempt: use Google Earth, Put place markers in the corners of your terrain, save the satellite image as a jpg, crop in photoshop to the corners, and then project over your terrain. The trick here is getting the satellite image boundaries to exactly match your DEM boundaries.

 

Google Maps has higher res images of the area I was working on, so I took a more complicated route and used Google Maps at its highest rsolution, took screen shots, trimmed away the screen borders, used Photoshop to create a panorama, cropped to the corner markers, and projected that larger map over my terrain.

 

Check out the attached .jpg (zoom in - it's 3300x2550) On youtube, search for xcoG1lzCJks or "mill valley muir beach" (change the res to 720p HD. The camerawork is not great, but I'm just starting with this.

 

I might put together a tutorial on this technique.