Mapping Mission - how the "Load Terrain From Bitmap File" feature works ?

[Bogdan]

Hi Gentlemen,

Just one question about the fantastic Mapping Mission software in general, and about the "Load Terrain From Bitmap File" feature in particular.

Load Terrain From Bitmap File This popup menu contains several related commands. All of these commands prompt the user to select a bitmap (*.bmp) image file. The file can be of any color depth. The bitmap file will be opened and read by Mapping Mission, and the current map will be modified so that tiles corresponding to pixels in the bitmap that are not “white” will be changed to the appropriate terrain type. (“White” in this case is defined as having the sum of the red, green and blue intensity values greater than or equal to 750.) Tiles corresponding to white pixels in the bitmap will be unchanged. The Load Elevations From Bitmap File command works slightly differently: each pixel is examined and its brightness is used to set the tile’s elevation value (from 0 to 255). Note that this elevation value is in levels, not meters. To determine the brightness required to set a given elevation in meters, divide the elevation in meters by 1.25 and round to the nearest integer. Then set the pixel so that the red, green and blue intensity values all equal this value. IMPORTANT NOTE: Mapping Mission inspects only one pixel for each tile in the map; adjacent pixels are not inspected. The specific pixel inspected depends on the width (height) of the bitmap in pixels compared to the width (height) of the map in tiles. For example, if the current map is 50 tiles wide and the source bitmap is 100 pixels wide, Mapping Mission will examine every other pixel when assigning tiles.

Is anyone here kind enough to explain to my tired brain how this really works, with examples ? I never tried this and wonder how can I use this specificity.

Thanks

[Sergei]

Here's an example (resized) of a file that I used to convert the forests from a topo map. The Mapping Mission understands the dark areas as forested. To get this, I used some functions and gimmickry in Paintshop Pro to get all the green areas on the map and turn this into a black and white image.

[Bogdan]

Thanks for this explanation, Sergei.

More about the size of your picture : do I understand correctly if one pixel in your picture is for one tile in CM map ?

This feature may only work for forrests and water areas. I cannot really imagine for which other kind of terrain this tools can be usefull :confused:

[Sergei]

Originally posted by Bogdan:

Thanks for this explanation, Sergei.

More about the size of your picture : do I understand correctly if one pixel in your picture is for one tile in CM map ?

No.

Well, it could be that way, but read the "important note" in your quote. It means that my file might be twice the size of the map, but MM would take this into account by only checking every other pixel.

Experiment!

Originally posted by Bogdan:

This feature may only work for forrests and water areas. I cannot really imagine for which other kind of terrain this tools can be usefull :confused:

It works for anything that you have useful data for. Producing that data depends all on your sources and your picture editing skills.