So you are using a custom terrain that is not included in the terrains folder when you first install FH? If so, all you need is the picture file to put in the download. The material file is just to get the terrains into the map maker. You don't have to include that, but maybe include a README that says:
"Open up DefaultTex.mat and at the bottom insert this:
NameOfTerrain.jpg
And then save it." Where NameOfTerrain is what you named your terrain and it has to be a .jpg. This is optional, they don't need to do this part to see the map.
