private static Image createEmptyLayeredImage(int width, int height,
            int layerCount, Image.Format format) {
        ArrayList<ByteBuffer> layers = new ArrayList<>();
        for (int i = 0; i < layerCount; i++) {
            layers.add(null);
        }
        Image image = new Image(format, width, height, 0, layers, ColorSpace.Linear);
        return image;
    }
Face of the Cubemap as described by its directional offset from the
origin.
jme3-core/src/main/java/com/jme3/texture/TextureCubeMap.java