Go to "FeralHeart > media > objects > myRocks".
Copy the rock.material file.
Go to "FeralHeart > media > objects > my_objects".
Paste the file in there.
Now right click on the file and Rename it to something else, then open it and change the first entry to this:
material yourMat
{
technique
{
pass
{
cull_hardware none
cull_software none
texture_unit
{
texture yourTex.jpg
}
}
}
}
and remove all the other entries. (you can add more of your own if you want to.)
Then go to "FeralHeart > media > terrains > textures" and find the texture you want to use.
Copy it & paste it into "FeralHeart > media > objects > my_objects".
Now you should be able to load the ground texture you want by typing yourMat into the material field of the object maker.