Flatten Flight Simulator terrain
Flatten bgl files can be used to flatten terrain mesh to a fixed elevation in most locations.
Airport scenery includes several components, not all of which are always aligned correctly with the airport elevation.
This can cause problems with disappearing taxiways and parking areas, bleeding of grass through the pavement ...
This problem occurs with both default and enhanced mesh. The solution offered here involves the creation of small "Flatten" bgl
files for the airports. These files will adjust the airport elevation to that indicated in the Map View data for the airport. This often resolves the problem.
Lakes and ponds at elevations very different from the surrounding terrain. These are excellent candidates for this type of fix.
When care is taken in selecting key points around the perimeter, the improvement can be dramatic. Use the Ground Elevation value to
determine the best elevation for the Area.
Flatten switches can also be used, but are limited to rectangular shapes, and a maximum of 10 per scenery layer.
The application uses FSUIPC (already registered) to track aircraft position and ground elevation. Two approaches are supported:
- Area16N: Use to define a new "feature" and specify its elevation. This approach is easiest, works anywhere,
and should be sufficient for most purposes. Simply Slew the aircraft around the perimeter of the area to be
flattened, recording key polygon vertex locations with a mouse click as you go. Once the area has been defined,
a single mouse click creates the bgl file immediately using these stored pairs of vertex coordinates.
(Named for the SCASM function which creates the bgl file.)
- LWM: This approach involves editing (mostly automated) the information FS uses to define existing "features" in the sim
(LWM polygon data). While elegant in concept, it is more complex, and requires at least a casual understanding
of the Scenery SDK, more computer literacy, and a bit of patience as well. For lakes, it also requires use of
the hyp*.bgl files provided with FS2002.
This approach works well when using a grid overlay in the sim to help identify LOD13 quadrants.
You can download my system here: fstutilities.zip (6 December, 2003)