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How to get terrain heightmap and satellite texture into Terrain Builder using Global Mapper. www.globalmapper.com
This page is created with Global Mapper v18.0 b101416 (but we also have short v13 info).
Using existing ASCII Grid .ASC heightmap file.
This ASCII Grid ASC tutorial assumes you have downloaded heightmap from using heightmap-real-world-data.
Terrain:
all done
Global Mapper v18 Digitizer Tool RMB menu:
Global Mapper v18 Export Menu menu:
Global Mapper v18 Digitizer Tool RMB Advanced Feature Creation:
Global Mapper v18 Digitizer Tool RMB Create Area/Polygon Features:
We use online map sources, world imagery, to download satellite texture.
Satellite texture:
all done
Our attempts to export 40960 x 40960 resolution world imagery satellite texture ended up Global Mapper freezing with 0% CPU usage. We don't know if there is some specific image size which start to cause these freezes, 20480 x 20480 images seem to export fine though and most terrains out there are ok with this size. See also Terra Ingocnita satellite texture part.
If you are exporting very large satellite texture, its good idea to split it up for smaller tiles. This is usually done by 2 x 2 but could be done as 4 x 4 tiles too, however in our example we use 2 x 2 tiles.
This assumes you have read world imagery satellite texture part so you know how to export satellite image.
As mentioned you could also use 4 x 4 so type in value 4 then.
After you've chosen the tile setup, continue exporting from export bounds tab.
With 2 x 2 setup the tile names are as following:
A1 top left
A2 top right
B1 bottom left
B2 bottom right
If you have a very large, huge, satellite texture like above 40960 x 40960 resolution, it basically needs to be exported as tiles. Not only tiles but enough tiles so the tile size remains small, do not exceed 20480 resolution!
We would recommend tile size more close to rough 10,000 to keep them nice and small. Yes the more tiles you have the more cumbersome they are to import into terrain builder, but once you have exported the tiles you can use imagemagick to stitch them together for more import friendly sizes if that's what you want.
If you try to export too large tiles, then global mapper writes the BMP files somehow incorrectly and they are not readable with photoshop (or imagemagick). For example we tried to export 35,500 resolution images and it failed.
When importing these tiles into terrain builder you can use even larger resolutions so you can stitch these tiles together and import only 2 x 2 tiles instead of 25 hehe. Use good numbers for tiles, like 2 x 2, 4 x 4 and 5 x 5. There are bad tile grid setups, here is example table of different resolutions divided by values:
20480 2 == 10240 3 == 6826.666666666667 4 == 5120 5 == 4096 6 == 3413.333333333333 7 == 2925.714285714286 8 == 2560 40960 2 == 20480 3 == 13653.33333333333 4 == 10240 5 == 8192 6 == 6826.666666666667 7 == 5851.428571428571 8 == 5120 81920 2 == 40960 3 == 27306.66666666667 4 == 20480 5 == 16384 6 == 13653.33333333333 7 == 11702.85714285714 8 == 10240 102400 2 == 51200 3 == 34133.33333333333 4 == 25600 5 == 20480 6 == 17066.66666666667 7 == 14628.57142857143 8 == 12800
As you can see you should not export tiles 3 x 3, 6 x 6 and 7 x 7 because they wont be even numbers, global mapper rounds UP the resolution and then you end up with 2 pixel too large tiles. I doubt nobody want to export much more tiles as even the 81920 resolution drops to 20480 with four tiles.
This is not very important, its just your own convenience when importing few or many tiles into terrain builder, if you get global mapper to successfully export 40960 then that's great
Rule of thumb:
When you have saved large satellite texture image using Satellite Texture Terra Incognita into OziExplorer .map file tiles, you should create map catalog for them.
This map catalog helps global mapper to handle large amounts of OziExplorer .map satellite texture tiles without causing heavy performance loss or memory usage.
The map catalogue is shown in global mapper as blue grid with red backgrounds when you are zoomed out, when you zoom in it will load those satellite images.
If you have very small satellite images or few of them, then this map catalog creation might be not needed, experiemnt it and see for yourself.
When you use digitizer tool and create grid, it will have a label in center of the grid. You don't want this as it will be printed on any satellite texture you export.
To delete the label select digitizer tool, double click on your grid to bring up modify feature info dialog, then just erase (select and hit DEL key) the text on name field.
Create grid (user created features), then click globe button (connect to online data) and tick “download within currently selected polygon(s)” and it only opens/downloads the data into your selected grid.
Select your user created feature layer and digitizer tool. RMB to your grid → advanced selection options → select all line features within the selected areas → select no option.
How to crop / clip your roads shapefile in Global Mapper v13 b121011 by M1lkm8n
This exact same method do not work in global mapper v18, it just saves the whole shapefile as is without any cutting, clipping or cropping :(