Hello Thomas:
Is this for use with a custom photo-real aerial imagery land class type of scenery created via FSX / P3D SDK Resample ?
If so, you can use a Water Mask and/or Blend Mask to define water bodies using either raster-only methods, or a combination of raster-to-vector methods, and even vector-to-raster methods with graphics and GIS applications to achieve a final resulting water mask that matches the size and shape of any desired water areas otherwise visible within your source photo-real aerial imagery.
The resulting custom photo-real aerial imagery land class type of scenery created via FSX / P3D SDK Resample would be draped by the FS rendering engine onto any underlying terrain mesh and/or CVX vector 'flatten' areas active in the scenery area of interest.
The result, therefore, would be both mesh-clinging and FSX / P3D "non-legacy" SDK compliant.
IIUC what you are trying to achieve, the following is a general conceptual over-view of a possible work-flow:
'Append' / import to
SBuilderX the OSM water body data as ESRI Shape (aka "SHP") files (or instead as GIS application converted BLN files, which IIRC, would result in SBuilderX ignoring the Altitude portion of that data) yielding poly-lines / polygons with vertices that can be manually aligned where needed to match the water bodies of the photo-real aerial imagery background map from your choice of tile server within the
SBuilderX work-space.
The resulting vector object(s) could be exported as a CVX vector BGL.
That CVX vector BGL could be de-compiled in Patrick Germain's
CVXExtractor with output as ESRI Shape (aka "SHP") files.
The resulting Hydro ESRI Shape (aka "SHP") file(s) could be converted from vector-to-raster via special features in a GIS application, then output as
GeoTIFF for use in creation of a Water and/or Blend Mask along with your other source photo-real aerial imagery.
However, since OSM vector data may vary in accuracy relative to position and shape in the real world, alternatively, you may wish to instead use the new tile server DLLs
Google_api3_Satellite for the photo-real aerial imagery and
Google_api3_Water ...in
SBuilderX for both the color satellite imagery and
matching gray-scale raster
water body imagery (derived from the same color satellite imagery).
Each of those imagery types can be output by SBuilderX to
BMP files with an accompanying 'world' Geo-referencing file, as SBuilderX creates a 1-piece
BMP and a matching
TXT Geo-referencing 'world' file when one performs
these steps:
1.) SBuilderX Menu > File > Add Map > From Background ...
2.) Select desired aerial imagery area, then download all tiles as directed in "Add Map From Background" dialog
3.) Select desired aerial imagery area from resulting aerial imagery Background displayed in SBuilderX work-space
4.) SBuilderX Menu > File > BGL Compile ... <
DO NOT 'click' [
Compile] button >
5.) SBuilderX pre-assembles a 1-piece aerial imagery
BMP and a matching
TXT Geo-referencing '
world' file in:
[SBuilderX install path]\Tools\Work\ sub-folder
...
without having actually compiled a BGL.
The resulting 'water'
BMP and its matching
TXT Geo-referencing '
world' file can be processed in a graphics application to assign the desired Gray-scale value (
ex: RGB 128,128,128 or less) that may be used in the Alpha Channel for a transparent water (Hydro) attribute that allows underlying color photo-real aerial imagery to show through.
Alternatively, a 'absolute Black' color (RGB 0,0,0) may be used in the Alpha Channel for a non-transparent water (Hydro) attribute to
prevent the water portion of underlying color photo-real aerial imagery from showing through, thus replacing it with FS default water when the scenery is displayed at run time.
If necessary, the resulting 'water'
BMP and its matching
TXT Geo-referencing '
world' file can be imported into a GIS application
BTW: Also, if necessary, the resulting
BMP and its matching
TXT Geo-referencing '
world' file can be imported into
ScenProc via "
ImportGDAL":
https://www.scenerydesign.org/2014/01/import-resample-configuration/
...and then exported as a
GeoTIFF via "
ExportImage".
And, if necessary, the "water"
GeoTIFF can subsequently be converted from raster-to-vector via special features in a GIS application after any desired additional processing.
[
EDITED]
PS: The FSX / P3D default "
original water polys" (which can also have their own local Altitude and/or Slope attribute values relative to local terrain mesh and/or CVX vector flattens) ...may also need to be excluded via "Exclude Specific" types of CVX vector exclusions which target the GUIDs for the default water bodies you wish to eliminate from display in FS at run time, thus allowing your custom 1-Meter terrain mesh to provide the (only) local surface onto which the water body pixels in the aerial imagery are to be draped.
[
END_EDIT]
I hope this might prove helpful with exploring your options.
GaryGB