so this only works in the adventure creator. so what you are gonna do is create an any color gate no keys and what your gonna do next is disguise the gate you picked then select a vehicle or a building then go to the sporepedia in the editor then select the paper then select a cell creature or anything that shows up in the top above the search then once the thing you want is selected. go into the editor then press the checkmark when your done and if you edited save it as a new then all done! you can now start creating a megabuild! you can do the same thing again for another peice for your megabuild.