Hi Nick,

there are 2 little problems in your map mapdem.gmap.

#1:
I have rebuild your DEM file. Maybe, builddemfile had the N50E000.hgt.zip or N50E000.hgt not found and you have only "dummydata" in your file. "dummydata" means a valid DEM with "no data"-points.

builddemfile --hgtpath=yourpath --dem=87827699.dem --tre=87827699.tre --dlon=0.00027777;0.00055555;0.00111110;0.00222221;0.00888884

create a DEM file with 23781 Byte.

#2:
Like Andrzej wrote: you need also a new TDB. I have used a quick but very dirty method: I have only for TDB-build temporary created the Tile IMG's ov.img and 87827699.img.

gmtool -i mapdem\*.*   --join=tile -o ov.img
gmtool -i 87827699\*.* --join=tile -o 87827699.img
gmtool -i *.img --mapsource=pid:1;fid:3927;cp:1252;ov:ov.img;tdb:neu.tdb;noov;notyp;nomdx;nomdr;noinst --mapfamilyname=mapdem --mapseriesname=mapdem --description="Test preview map" --routable=1 --highestroutable=24 --maxbits4overview=18 --hasdem=1 --hasprofile=1 --copyright=*I* -o . --overwrite
ren mapdem.tdb mapdem.tdb_
ren neu.tdb mapdem.tdb
del *.img

Of course, in your little demo we can not see a shading. But we can see the values for N, E and height in the basecamp status line.

By the way, be careful wit --usedummydata. It's only interest for sea-areas, where don't exist a HGT. But if a HGT for land is absent, we have a hole in our map without an error message!



Frank