void createRedSquare() {
        Mesh quadMesh = new Quad(1f, 1f);
        Geometry redSquare = new Geometry("red square", quadMesh);
        Material red = assetManager.loadMaterial("Common/Materials/RedColor.j3m");
        redSquare.setMaterial(red);
        rootNode.attachChild(redSquare);
    }
Attach a red square in the XY plane with its lower left corner at (0, 0,
0). It is composed of 2 triangles.
jme3-core/src/test/java/com/jme3/scene/PhantomTrianglesTest.java