It sounds to me like you're looking for a more straightforward solution than what jME can currently offer. Actually, it sounds like you've got some reading up to do on the whole process of making a game.
By and large a game engine does not actually create content/assets for you; instead it lets you arrange and display these assets in a nice way, as well as applying certain rules to them, e.g. physics values.
To learn more, these are some good places to start: