public static Spatial createSky(AssetManager assetManager, String textureName, EnvMapType envMapType) {
        TextureKey key = new TextureKey(textureName, true);
        key.setGenerateMips(false);
        if (envMapType == EnvMapType.CubeMap) {
            key.setTextureTypeHint(Texture.Type.CubeMap);
        }
        Texture tex = assetManager.loadTexture(key);
        return createSky(assetManager, tex, envMapType);
    }
Create a sky using the given cubemap or spheremap texture.

@param assetManager from which to load materials
@param textureName the path to the texture asset 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