public static Spatial createSky(AssetManager assetManager, Texture texture, EnvMapType envMapType) {
        return createSky(assetManager, texture, Vector3f.UNIT_XYZ, envMapType);
    }
Create a sky using the given cubemap or spheremap texture.

@param assetManager from which to load materials
@param texture to use
@param envMapType see {@link EnvMapType}
@return a new spatial representing the sky, ready to be attached to the
scene graph
jme3-core/src/main/java/com/jme3/util/SkyFactory.java