Using MicroDEM to make map_C files.
I have been reminded that I promised to give a tutorial on making map_C files using this program. Apologies for the delay, but for some reason I became sidetracked
There are a couple of methods, and some may be better, but this is the one I generally use. I am assuming that you have finished making map_h and map_T, so the same map is still loaded with all corrections to missing data applied. If you are reloading then make sure you apply missing data corrections as shown earlier.
Now there are two ways to approach this.
Remember that for map_h and map_T we set the map size to 1 pixel = 200m because this is what IL2 uses. But for map_C, IL2 uses 1 pixel = 50m. It also uses RGB = 0 for water, RGB = 255 is land and the greyscales in between are shallow water/smooth shorelines.
Method 1, set the mapsize in MicroDEM to 1 pixel = 50m, but you wil have to Blur the edges in Gimp or a similar picture manipulation program to get nice water edges.
Method 2, set MicroDEM to 1 pixel = 200m and scale the image up in you picture program. In Gimp this will automatically give a greyscale/antialaised edge to the map_C.
Lets start at sizing the image:
Go to menu:
"
Modify"
"
Map Area"
"
Set Map pixel size"
since we are making a map_C, change the value to "
200.0" or “
50.0” depending on the method you want to try and press "
OK"
Go to menu:
"
modify"
"
display parameter"
Select "
Reflectance"
Then select the "
Vert Exag" to “
0” (You have to click in the box and type “0”)
Click the “
water” button, select black for water
The “
colors” button, select “
grey”
Ensure the following are ticked, “
Sea Level Check”, “
Lake Check” and
Diffuse Reflectance”.
Click “
OK”
The map should now be a black for water and grey for land image.
Now to save the map: go to menu:
"
File"
"
save image"
I always save as a BMP image then edit and crop in Gimp. If you are using Gimp, do the following to get a black and white image. But remember this will remove any grey areas in the map!
Menu:
“
Colours”
“
Threshold”
Adjust until you get a black and white image, press “
OK”. If you are applying a blur or resizing from 200 to 50m per pixel to get "automatic" greyscaling of the water edges, do this now, then save.
All done apart from resizing to a multiple of 32 and using the tools supplied by fly_zo to make a map_C and map_C_table for IL2 as explained elsewhere in the forum.
If you come up with better or alternative methods, please add/post your info.
CW