Yer i've just downloaded Paint.NET that i think works. I'm not sure on the dimensions though.... My structure is to be double the size of the purple/pink area for a Town Hall. So would that be 32x32 for the doubled version?
If you want to see the dimensions of the path of the townhall, you can use a MPQ editor in order to open the wc3 archive and then extract that pathing map. You are then abled to open it in Paint.NET so that you can see how big the pathing is, if it needs to be twice that size simply create a new TGA file of twice the size of the pathing map from the town hall.
I suggest you'd use this MPQ editor in order to do that:
http://www.zezula.net/en/mpq/download.html
The pathing is stored inside the folder: 'PathTexures'
Make sure that you open war3.mpq with the mpq editor.
war3.mpq contains all the data from warcraft 3 reign of chaos.
war3x.mpq contains all the data from warcraft 3 the frozen throne.
Since the townhall also exists in warcraft 3 reign of chaos the pathing for the townhall should be in war3.mpq.
war3.mpq and war3x.mpq are in your warcraft 3 installation folder by the way.
Also: did you know that it is possible to open a map with an mpq editor in order to extract, import data or to fix fatal errors of that map?
If you are unabled to open war3.mpq or war3x.mpq make sure that you haven't got the world editor or warcraft 3 open while opening the archive.
If you want to know which pathing file is used for the town hall, press control + D inside the object editor to see the raw data.
In this particular case the pathing map that is being used for the townhall is called:
PathTextures/16x16Simple.tga
So your texture should be 32x32 if you want a pathing doubled that size.
