self.toolbar_frame = tk.Frame(self)
self.canvas_frame = tk.Frame(self)
self.progressbar_frame = tk.Frame(self)
self.toolbar_frame.pack(fill=tk.X)
self.canvas_frame.pack(fill=tk.BOTH, expand=tk.TRUE)
self.progressbar_frame.pack(fill=tk.X)
self.model_loaded = False
self.destroy()