Hi, I'm struggling with creating a basic "slow to a stop" of some stock footage of a x-ray brain spinning. I'd like the brain to stop spinning, not abruptly, but slowly, over thirty frames or so.
Have learned a lot from Stephen Smith's great DVD tutorial "Moving with Motion" but still can't lick this one.
I've gotten pretty good results from doing two steps:
1) keyframing the Retime Value of the clip and adding a Bezier interpolation (only requires two keyframes)
2) adding the Retiming Behaviour "Hold Frame" just before the second keyframe.
This works, except that with the nice slowdown that the Bezier gives, it also ramps the speed up at first before slowing the clip down.
Well, you CAN use keyframes to do this kind of animation, although to avoid it changing the speed from the beginning, you need 3 keyframes, not 2. The first keyframe should be at the beginning of the clip, the 2nd at the point where you want the slow down to start, and the 3rd at the point where the clip is to stop (also, potentially a 4th set to the same frame to keep the hold).
However, since it's just a simple ramp slowdown, here's how I'd approach it with behaviors only.
Add the Retiming/Set Speed behavior to the clip and trim the in point to where I want the slow down to start. Leave the out point at the end of the clip.
In the behaviors tab, set the speed to 0, the ease in time to 30 frames and the Ease In curve to 100. Then make the Ease out time 0 so it doesn't try to ramp back up to full speed at the end of the clip.