图形驱动程序排队的最大帧数。
图形驱动程序可以对要渲染的帧进行队列处理。当 CPU 的工作明显少于显卡时，
该队列可能会变得相当大。在这种情况下，
用户的输入将“落后于”屏幕上的内容。
使用 QualitySettings.maxQueuedFrames 可限制排队的最大帧数。在 PC 上，默认值为 2，
可在帧延迟和帧率之间达到最佳平衡。
Note that you can reduce input latency by using a smaller maxQueuedFrames because the CPU will be waiting until the graphics card finishes rendering previous frames. The downside of this however, is that it can result in a lower framerate.
Currently maxQueuedFrames is implemented in Direct3D 11 and Direct3D 12 graphics APIs. See platform-specific documentation for information about other graphics APIs where maxQueuedFrames is implemented. maxQueuedFrames is ignored by other graphics APIs.