FS2004 Scenery

Problems with mesh

The screenshot below shows the default FS coastline at Douglas Head. Note the lighthouse in the water which is correctly placed and should be at the tip of Douglas Head - an indication of how wrong the default coastline is.

The terrain used is the LAGO TerraMesh for England and Wales. Not bad but later SRTM meshes are a lot better.

After reworking the coastline with CoastLineMaker the picture looks better:

The obvious problem in the above shot is that although the land now looks like the true IoM coastline the mesh has remained unchanged. Let us see the same shot but with the VFGM photo scenery now active.

Again, it is apparent that the mesh is not correct. It should be - most meshes are correctly set to WGS84 datum - but it has not altered from that in the original FS scenery. The solution was found when I turned off the NWEurope scenery area:

The mesh is now perfectly accurate so the problem lies back in FS. In fact, despite revising the coastline, you will see that the default coastline in FS is still partly active and has an unwanted attribute - it truncates any mesh. Any mesh extending past the default FS coastline is, effectively, "chopped off" and will not flow to cover the added coast I have built. Unfortunately this also means that all revised coastlines extending seaward of the default coastline are similarly affected.

The Water Mask files

Further investigation showed that the coastline data is found in the HYP prefixed BGL files. For the IoM coastline this is:

FS2002  Scenerydb/NWEurope/HYP544252.BGL.

FS2004 HP946120.BGL

One can disabling these BGL files to make the revised coastline work but it is not ideal. HYP544252.BGL covers a large area and switching it off affects all the UK coastline in a horizontal band from Llanbedr right up to Edinburgh. Turning it off gives a lovely IoM coastline but the rest of the UK coast disappears! Daft but this is how MS built FS scenery - putting down huge blocks of land and then trimming these off by defining a coastline that automatically sets one side to land and the other to sea.

Regretfully, rebuilding the coastline does not inhibit the mesh truncation properties of the default FS coastline. I have not yet found a solution for this although it may be possible to disable the code in the HYP file. I am looking into this.