Listen to this. To create the 3d models you can either use the primitives or load it from a 3d file.
If you want a complex 3d object like a car, a person, etc etc etc, load it from a 3d file. You can make the 3d file with any 3d modeling software capable to export to .3ds (primary) or md2. Misfit is one of them, but there also exist strata studio pro, 3d studio max, lightwave, etc etc etc.
Once you have the model exported to a 3ds file, you can load it into java using jpct and its class called "Loader"