Flight Unlimited III high resolution terrain processing workshop

noncommercial FU3 support page - just to keep FU3 flying !

Terrain height modification using gmax®

Principle of terrain shape corrections

Main difficulty in terrain shape correction is the synchronization of the elevation model with the texture. Bad results are river on hill top, lakes on a hang and hill reaching into lakes or the sea. Using gmax® of discreete make it possible to modify single elevation meshes on a plane with the texture as overlay. Now the exact setting of hills and valleys are possible even still a time consuming work.

We will use the MD3 format as interface between FU3 and gmax®. The export/import from the geotiles.tag file is accomplished via GeoTilesViewer V3.0. The interface is hold as simple as possible. The mesh counts of a plane in gmax® is limited to 200x200 so it is not possible to handle a full megatile at once. The megatile is broken up into 4 overlapping parts of 192x192. If you modify just an area around an airport, you don't need to modify the full tile and can just concentrate to the needed part. At import the part is mixed to the remaining tile. Never change elevation at the border of such an area or you will get bad steps in your landscape. Modify the elevation only. Never add, reduce, move or manipulate the position of meshes. The only thing you may change are the elevation, the value of the Z axis of the meshes. As long you affect the Z axis only every manipulation is allowed. The import function will use the Z values only, but adding meshes will confuse the import resulting in unpredictable elevation.

As always backup your files and be aware that
You are using this freeware tool and the tutorial at your own responsibility !

In this tutorial we will use a megatile from the UK-South region, Bembridge bmam

Preparation of the needed files

  1. Using GeoTilesViewer 3.0 select the tile you want change (l5bmam)

  2. export elevation getting the file e0bmam.tga

  3. export classification getting the file cl5bmam.tga

  4. close GeoTilesViever.

  5. create a new workfolder containing: GeoTilesViewer.exe, a blank geotiles.tag file and the exported files e0bmam.tga and cl5bmam.tga.

  6. Rename the blankgeotiles.tag in geotiles.tag.

  7. from now work in this area. then import in a small geotiles.tag is much faster. to check the results just rename the geotiles.tag in the region geos folder to another name and copy the small geotiles.tag to this place. Start fu3 and look at your elevation. All other tiles are then flat and defined by the blank tile.

  8. open this new geotiles.tag file and add a new tile, keep the import of elevation and classification checked.

  9. For the Bembridge example we need the upper right part of the tile. Open the geotiles.tag file with GeoTilesViewer, select the l5bmam level 5 elevation and export the elevation using the UR button in the MD3 export section.


  10. close GeoTilesViewer.

  11. Now we need the corresponding texture. The tool for that is GenQuadrant V2.5 Copy the file l0bmam.bin from the region map folder to your working area of Genquadrant. Start Genquadrant have the San Francisco palette selected and open l0bmam.bin. Save the L0.tga map and load this 16MB file in your drawing tool.

  12. We must cut the picture to have the upper right part so cut 1024 from left and 1024 from the bottom (set bottom to 3072 or 3071 depending how your tool is counting the pixel). At the end you must have a 3072x3072 picture.

  13. reduce this picture to 768x768. This is the best resolution of the texture in gmax® for our 192x192 plane. If you use higher resolution there will be no visual differences just heavier load and space size. Save this file with any name here txbmam.tga

The gmax® session

  1. Start gmax®. Set the unit in the units setup to generic units. The elevation values of Z is then in 10m per units. A Z value of 5.6 is then for 56m. Other settings was not successful.


  2. Select import choose md3 as file type, navigate to your folder and load l5bmamUR.md3.


  3. set the windows options to Smooth and Highlights

    smooth and highlights

  4. now you can see the terrain in 3D space.

    first view

  5. Keep the Plane selected and open the material editor button mateditor

  6. Click on new and select Standard material

  7. deploy the map section and select the diffuse color map button

  8. double-click on the black bitmap square

  9. select your texture file from the file window txbmam.tga

  10. Select the mapping to Planar to ObjectXYZ select Show Map in Viewport and click on Apply

  11. close Material Editor.

  12. from now you can see the texture over the elevation.

  13. Keep the Plane selected and choose Modify and select Editable Mesh from the Modifier List. In the Selection part choose Vertex.


    Now you will see the mesh points.

  14. Select a single point and using the Gizmo. In the Z window at the bottom you can read the elevation in 10m per units. For the Bembridge airport area we see a value of Z=1.0 for 10m, you can enter a new value also.

  15. To modify the elevation have the button Select and Move move and Restrict to Z zonly activated. You can now select multiple points by the standard method of gmax® and scale or move the selected group to any elevation. Modify the vertical Z part only. Never modify any thing else. Do not load other objects in the workarea.

  16. After editing, deselect the modify function and select Export from the file menu. Select Quake III (*.MD3) and enter a new file name, Bembridge.md3

  17. select frame 0 and click on Export now

  18. You can save your work as gmax® file also. Then close gmax®.

Import your edited work

  1. Go back to your GeoTileViewer Workarea and have the new Bembridge.md3 files there also.

  2. Open GeoTilesViewer select the l5bmam node and select elevation import.

  3. In the import MD3 file section enter the new file name, Bembridge.MD3 and click on the UR button to load this elevation in the upper right part of the tile.

  4. The modified elevation is now imported and ready to use, copy geotiles.tag to your fu3 area (first rename current geotiles.tag there) and take a flight.

  5. Finally save your finished elevation tile in the standard elevation format e0bmam.tga as a small file for distribution on the net.

gmax is a Trade Mark of discreete, www.discreete.com
the needed MD3 plug in is from Tempest

under construction last update 20.feb.2003

Information: André Meystre
back to FU3 Terrain Workshop      next to making of high res region