Paul Pingrey created this image using Digital Line Graph (DLG) data as a terrain overlay in 3DEM.
Paul describes his technique below.
3DEM doesn't directly read DLG data (vector data for topographic lines, roads, section lines, etc.). By using 3DEM and the free USGS dlgv32 viewer together, you can, however, make 3D terrain images including DLGs. Dlgv32 displays DEMs, DRGs, DLGs, DOQ's and other cartographic data. It does not, however, save projects or produce the oblique views or flybys you get from 3DEM.
Process
1. Download the 7.5' DEMs and related DLG data for an area of interest from GeoCommunity.
2. Open the DEM and related DLGs in dlgv32. Use the control center in the tools menu to turn on DEM smoothing (bilateral interpolation) and turn off the light source. Adjust the width and colors of the line data to your liking.
3. Zoom to an area of interest. Write down the lat/long coordinates of the NW and SE corners of the display (move the cursor to the two corners and observe the coordinates that are displayed). You will use the coordinates in 3DEM to geo-reference the image you will be saving.4. Take a screen shot of the image. Use print screen and a paint program or use a screen capture program like Grabber2K. If you use Grabber2K, capture in "object" mode to save just the DEM image without the frame. Save the captured image as a BMP or TIF file, never as a JPG. Then exit dlgv32. To get the best quality image to use in 3DEM, increase your screen resolution to the largest size that your installed video card allows at high color. You can switch back to 1024x768 or other size later. Regarding lat/long coordinates, you will need to convert the degree/minute/second format used by dlgv32 to decimal degrees for use in 3DEM. A free converter is available.
5. Start 3DEM. Load the DEM for the region of interest. Load the image saved from the screen capture in step 4 as a 3DEM overlay. Use the coordinates you saved from dlgv32 to geo-reference the image. That's it! Experiment with 3D views. Save the views you like and add labels, legends or other information in your photo editing or drawing program.
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