static void Init()
    {
        Tool_ObjectPlacement window = CreateInstance <Tool_ObjectPlacement>();

        window.title = "ObjectPlacement";
        window.Show();
    }
    static void Init()
    {
        Tool_ObjectPlacement window = EditorWindow.GetWindow(typeof(Tool_ObjectPlacement), false, "Tool_ObjectPlacement") as Tool_ObjectPlacement;

        window.Show();
    }