フレームが開始された時間 (Read Only) 。最後のレベルが読み込まれてからの時間 (秒) です。
This is the time in seconds since the last level was loaded. This is Read-Only. Double precision version of timeSinceLevelLoad. This offers more precision than a float or single value, particularly over extended periods of real-world time. In almost all cases, choose the timeSinceLevelLoadAsDouble equivalent over timeSinceLevelLoad.