What is the blocked.tga?
The blocked map (blocked.tga) is intended to block certain areas of a map. The reasons for blocked areas can be different, as you might want to block deep waters (e.g. to avoid highly unrealistic mega bridges) or maybe just small objects such as the turntable (to prevent the player from building through it and thus avoiding visual inadequacies). Dimensions: 512x512px.
How to edit it?
You will need to have an image editing software which supports exporting/saving to *.tga files. The image is working in 8Bit grey scale mode without any transparent areas. Furthermore, there are only two colours you have to worry about: pure black (0, 0, 0) and a very dark grey (5, 5, 5). The pure black will define the blocked areas and the dark grey areas will indicate playable areas. Make sure using a „pencil“ tool instead of a „brush“ tool as you have to avoid any gradients and you will need solid colours and hard edges only.
This feature does not work at the moment. Currently, the blocked.tga will not be created in the directory of your scenario (and it will not load from that folder either), but this will be implemented as soon as possible!