How to Import ArcGIS Maps into Fledermaus

These instructions will help you convert an ArcGIS map into a 3D Fledermaus object you can view on a regular computer or on a GeoWall. Because you are making a 3D object, you must have at least a DEM (Digital Elevation Model) or DTM (Digital Terrain Model). If you want, you can also drape one or more pictures over the topography.

NOTE: You MUST be connected to the network the entire time you are using Fledermaus, or it may suddenly interrupt what you are doing, possibly even losing your work, because it cannot renew the license.

Load DEM into Fledermaus

• Start, Programs, FledermausPro, DMagic
• If the title bar does not already show the directory where you want to work, you MUST do one of:
  • Project, New
    • You can leave the Project Name blank.
    • Browse to your desired Project Location. Create a new directory (AKA folder) if needed.
  • Project, Open
  • Project, Recent
  This is merely choosing a current directory so your files will appear in the Data Components list.
• File, Import Surface
• Choose the ArcGIS file that has the elevation data. If you find a directory named e.g. "dem", that is promising. Look for the biggest file in that directory. It may be named something like w001001.adf.
• Choose file type from list. Arcview Binary Grid may work.
• To check if you have the right file type, Scan for Information and see if the 8 numbers below the Scan button look about right.
• Under Surface Interpretation choose Output a DTM.
• Convert and Save.
• Name your new file to indicate where it came from, e.g. w001001.dtm.
• Save.
• When it says Successfully Converted File choose OK.
• Your new *.dtm should be listed in the Data Components section, together with a matching .geo file. Use the [>>] button to send both of them to the display area. (If you just use the [>] button, the height values of the dtm are not correctly calibrated.)

Surface Shader

You cannot Assemble Fledermaus Objects (later) without a shade file, so you have to make one whether you want it or not. To just make a quick easy shade:

• Surface Shader
• Start rendering...
• wait a moment
• Save shade
• Close.

If you want to tinker with it:

• With your .dtm activated (visible in the window) choose Surface Shader
• Adjust sun direction and height as wanted.
  • If your image is already shaded consider direct overhead light so that you don't introduce conflicting shadows.
  • Or at least adjust sun height from 0.50 to maybe 0.30 so shadows will be shorter on dramatic topography.
  • If you want as few shadows as possible, try setting all shader parameters to 0.
• For the Overlay Image IT IS NOT NECESSARY to choose your picture as the image to shade. You can just shade your .dtm instead. Either way, you have to shade something.
• Start rendering....
• If you don't like the shaded image adjust parameters and render again.
• When you like the shading, Save shade.
• Close.

Drape image(s) over topography

If you just want the topography by itself (no draped image) proceed to Assemble Fledermaus Objects.

• File, Import Imagery, Cut and drape imagery...
• Browse to find the image you want. Note that it accepts TIF JPG and BMP files. If your image is in another format you will have to convert it using some other program.
• Review the Georeferencing and if it looks right, choose OK. Large images will take a while to process.
• When it is done you should have TWO new items in your Data Components list: a .dtm and a .geo. One at a time, select them and use the [>] button to send them to the display area. Although you do not see your image on the screen at this time, it probably exists in your project directory and may even be bigger than the image you originally chose.

Assemble Fledermaus Objects

• If you have an image to drape over your DEM
  • Object to create: Textured DTM.
  Otherwise, to view the DEM by itself
  • Object to create: Basic Gridded DTM. (Or, if your DEM might have data holes -- locations where there is no elevation data known -- choose SonarDTM.)
• Height Object: choose your *.dtm produced from File, Import Surface.
• Geo-Ref Object and Shade Object should auto-fill; choose what you just created if they don't.
• If you are draping an image (using Textured DTM) then for Image File: Browse to choose your image.
• Object Name: If making a Textured DTM use the name of your Image File but with a ".sd" suffix. For a DTM with no image use the name of your Height Object but with a ".sd" suffix.
• Build Object
• It should say SD Object Built successfully. OK.
• Close.
• If Fledermaus is already running from a previous image in this same project, switch to Fledermaus. Otherwise, start it with the Run Fledermaus button.

Build a Scene with Multiple Images

If you are just viewing a single DTM with no image, or a DTM with only one draped image, you are probably done now. But if you want to combine several things, you need to make a .scene file.

• While viewing your first draped image in Fledermaus, choose Controls, Data Sets (unless it is already enabled).
• Change the Exag field if you want to set the vertical exaggeration.
• Select one of the .sd files in the list if you want to adjust its options. Most of these will affect rendering. You will have to experiment with these values to find the best trade-off between speed and visible detail. The High Resolution Texture setting is almost always desirable.
• File, Save Scene.
• Choose a name that represents the whole collection of images you plan to combine, not just the first image you loaded.
• Return to DMagic and import another image as above, starting from Drape image(s) over topography, and saving it to its own separate .sd file.
• When your additional .sd file has been made, switch back to Fledermaus with your existing .scene loaded.
• File, Open Data Object...
• Choose your new .sd file. It should open and be displayed adjacent to or on top of your previously loaded image(s). It will also be added to the list of objects under the Root Note of the Data Set Control. Adjust the parameters of this object as you did for the first.
• File, Save Scene.
• Choose the same .scene file you saved before, and choose Yes to replace it.
• Repeat until all desired images are loaded.
• You now have a .scene with multiple images or "layers" in it. You can turn each one on or off using the Data Set Control in Fledermaus, or using the View menu option in iView3D.

Possible Problems

You may get the message "Error reading in image file" followed by "Process Failed. Could not read image file." The cause is not obvious. This message has been seen with a 2.2GB GeoTiff file and also with a 176MB file but with a 283MB GeoTiff it worked one time yet it refused to take the same file later. Converting the GeoTiff to .jpg doesn't work either because it loses its geographic coordinates. Closing all other programs to free up memory didn't seem to help. There was well over a gigabyte of free disk when trying to read the 176MB file, so disk space shouldn't have been the problem either. Sometimes if DMagic refuses to read a file, simply exit and restart the program and it will accept the same file it rejected before.

Written by Marvin Simkin Filename arcgisfm.html Last updated April 5, 2007