Yes, sampling means ‘reading the value at a particular time’. Same sense as in signal processing. If everything goes to plan, you are sampling at 1/60, 2/60, e

Yes, sampling means ‘reading the value at a particular time’. Same sense as in signal processing. If everything goes to plan, you are sampling at 1/60, 2/60, etc. But if the previous frame took a bit longer to render, you might be at a different time. What you want is the value for all of those curves at whatever time it is, not at some fixed time.