The wiki's instructions I'm stuck at are at the point of using resample.exe.
but anyway... I am confused about:
http://www.fsdeveloper.com/wiki/index.php?title=Create_mesh_using_Global_Mapper
" In order to compile our BGL for FSX, we need first of all to create the Elevation_Data_Brest.inf, so that resample.exe knows what it has to do and how. "
...because what does this mean??
Do I need to create a file with Notepad++ and work from there??
Hi again, Alec:
With regard to the export from GM of elevation data as source files for FS SDK Resample, as I stated above, once you have the aerial imagery and elevation data required for your intended Geographic extents of coverage all downloaded into a GM "Workspace"
*.GMW project file, you must
first 're-project' your project within the GM work-space into the GIS data file format required by FS SDK Resample
before exporting into either a raster aerial imagery or elevation GeoTiff file ...as described in the explanation which follows below in this post.
CAVEAT:
An important consideration may be necessary when working with Global Mapper due to a change in behavior which was apparently implemented in more recent versions in that program.
It seems that Global Mapper (
sometimes) dynamically accepts and defaults to the internal projection settings of a GIS data file in order to import it and display it within the Global Mapper workspace ...
even if one has already set the default configuration of Global Mapper to be at "Projection: "
Geographic (Latitude / Longitude)", Datum: "
WGS84", Planar Units: "
ARC DEGREES".
So when one opens a GIS data file, it may by default be displayed in the same internal projection stored within that file.
To "force" the re-projection in Global Mapper to make the GIS source data display
and export in the format required when that data is to be exported for use with the FS SDK, one must
again reset the projection during the work session
immediately after one's first GIS data file is loaded ...via this procedure:
The correct configuration to set up in Global Mapper before opening a GIS data file or downloading GIS data ...and
AGAIN '
after' opening data files when that data is to be "Exported" for use with the FS SDK:
Global Mapper Menu > Tools > Configure... > [Projection Tab]
Projection: "
Geographic (Latitude / Longitude)"
Datum: "
WGS84"
Planar Units: "
ARC DEGREES"
Parameters:
Attribute: "
CENTRAL LONGITUDE"
Value: "
0"
BTW: As a visual clue that one has 'remembered" to re-project to WGS84 for
ex: FS SDK use, the Global Mapper workspace display of the GIS data should compress vertically and rotate counter-clockwise to some extent.
NOTE: Global Mapper is IMHO likely to yield more consistent results when the GIS file which one needs to re-project is the ONLY file loaded in a particular work session; thus it is preferable to
not attempt to use that file as one of multiple files which are being turned on and off in the "Control Center" within a work session.
If it is necessary to attempt isolation of a particular GIS file which one needs to re-project and/or export as the
ONLY "active" or visible file within a
multiple file layer work session, it may be likely to yield more consistent results when that GIS file is loaded
FIRST, re-projected, and
then load the other
multiple file layers afterwards.
Example settings in Global Mapper for export of elevation data
This configuration may work for certain source data file formats in Global Mapper
after downloading and opening a GIS
elevation data file ...when that data is to be exported for use with FS SDK Resample to output a terrain mesh BGL:
1.) Global Mapper Menu > File > Export > Export Elevation Grid Format...
2.) At 'Select Export Format' prompt, choose "GeoTIFF" from the pick list
3.) In 'GeoTIFF Export dialog, on [
GeoTIFF options] tab:
File Type: "
Elevation (16-bit integer or 32-bit floating point) samples (=Radio Button 'Ticked')
Vertical Units: "
Meters"
Resampling: "
Bicubic Interpolation"
Sample Spacing / Scale: (
disregard =Automatically filled in by Global Mapper)
Always Generate Square Pixels:
(=Checked)
Always Export At The Fixed Scale 1: "
0"
(=Not-Checked)
DPI Value To Save in Image (0 for None): "
0"
(=Not-Checked)
Compression:
Default (No Compression)
ADVANCED: Use Tile Rather than Strip Orientation:
(=Not-Checked)
ADVANCED: JPEG-in-TIFF Quality: "
75" (
disregard =Automatically filled in by Global Mapper)
Interpolate to Fill Small Gaps in Data:
(=Checked)
Generate TFW (World) File:
(=Checked)
Generate PRJ File:
(=Checked)
Generate OziExplorer .map File:
(=Not-Checked)
ADVANCED: Don't Write GeoTIFF Header:
(=Not-Checked)
4.) In 'GeoTIFF Export dialog, on [
Tiling] tab:
No Tiling - Just One Export File:
(=Radio Button 'Ticked')
Skip Existing Files (Use to Complete Cancelled Exports):
(=Not-Checked)
5.) In 'GeoTIFF Export dialog, on [
Export Bounds] tab:
All Loaded Data:
(=Radio Button 'Ticked')
...or:
Click "[
Draw a Box...]" button and select desired area from displayed workspace (or specify otherwise via the GUI in that dialog box Tab).
You should now have a elevation GeoTiff source file compatible for use with FS SDK Resample.
Now you must create a
*.INF file for processing of the elevation GeoTiff source file by FS SDK Resample to output a FS terrain mesh BGL.
For simplicity, you may wish to use Ollyau's "
GeoTiff-To-INF" utility to read the Geo-referencing within the file header of the elevation GeoTiff output by GM along with accompanying *.TFW and *.PRJ files, and which will then output a basic *.INF file with computed Geo-referencing parameter values.
http://www.fsdeveloper.com/forum/resources/geotiff-to-inf.119/
NOTE: Ollyau's "
GeoTiff-To-INF" utility (
as programmed thus far)
is only intended for use in creating a *.INF file structured for use with FS SDK Resample to output a custom photo-real aerial imagery BGL (from a aerial imagery source data GeoTiff).
However, with minimal editing in Windows NotePad (or NotePad++), a
COPY of
that *.INF can be modified for use in creating a *.INF file structured for use with FS SDK Resample to output a custom terrain mesh BGL (from a elevation source data GeoTiff.
Alternatively, the required Geo-referencing parameter values for a properly structured
*.INF file to be used in processing of the elevation GeoTiff source file by FS SDK Resample to output a FS terrain mesh BGL, can be derived from '
Metadata' for the original
United States Elevation Data (10m resolution) layer within GM's Overlay Control Center.
A detailed example of how to do the above edit with example *.INF files can be posted here ...upon request.
GaryGB