Cube wireframe with ability to place objects within

Hello all, I am very new to 3D programming and am trying to understand how to make the cube in the test a wireframe but still be able to see all the way through and be able to place objects within it. I need to put 3 spheres inside and make them bounce around for a homework assignment. I have searched through all the tutorials about this and haven’t got past just being able to change the cube to wireframe and change the color of the lines. this is the code for the cube I have but it is just standard right from the tutorials.

Box mesh = new Box(Vector3f.ZERO, 1, 1, 1); // create box mesh
Geometry geom = new Geometry(“Box”, mesh);

    Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
    mat.setColor("Color", ColorRGBA.White);
    geom.setMaterial(mat);
    rootNode.attachChild(geom);

    mat.getAdditionalRenderState().setWireframe(true);

Hi there,
Well the best thing I would use is the WireBox.

WireBox wireBox = new WireBox(1, 1, 1); wireBox.setLineWidth(0.1f);

You can also try setting depth testing off for your objects