最新の FixedUpdate を開始した時間 (Read Only) 。これはゲーム開始からの時間(秒)です。
Fixed time is updated in regular intervals (equal to fixedDeltaTime) until timeAsDouble property is reached. Double precision version of fixedTime. This offers more precision than a float or single value, particularly over extended periods of real-world time. In almost all cases, choose the fixedTimeAsDouble equivalent over fixedTime.