Geometry geom = new Geometry("A shape", mesh); // wrap shape into geometry
Material mat = new Material(assetManager,
"Common/MatDefs/Misc/ShowNormals.j3md"); // create material
geom.setMaterial(mat); // assign material to geometry
// if you want, transform (move, rotate, scale) the geometry.
rootNode.attachChild(geom); // attach geometry to a node