also need a reference to a material mapping file

src/main/java/ca/blarg/gdx/tilemap3d/json/tilemesh/JsonTileMesh.java

@@ -22,6 +22,7 @@ public class JsonTileMesh {
 		public Vector3 positionOffset;
 	}
 
+	public String materials;
 	public boolean cube;
 	public CubeTextures textures;
 	public int texture;