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Swing-down text effect
It’s easy to create a swing-down text effect (picture a horizontal sign swinging down from a cross-arm via a short chain on either end). I can add a few key frames where the sign swings down, overshoots, swings back and finally comes to rest and then make all the key frames Bezier, but it’s tough to eyeball the spacing of those keyframes to get a completely natural-looking swing that dampens over time.
I’ve tried all the parameters in the X-rotation setting but none give me swing that dampens over time. I can see a dampening effect in the Motion Path effect but that doesn’t appear to work with a rotation.
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8 Replies
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Hi Don
This is really easy to do with behaviors. Add an oscillate behavior to the X rotation, then add a Ramp behavior to the Oscillation amplitude taking it down to zero from whatever value you want to start with.
Works a treat.
You might want to play with the Curvature control of the Ramp behavior as well for extra finesse.
Simon Ubsdell
http://www.tokyo-uk.com -
Thank you Simon. It makes sense but I must be missing something because (if you can see the attached image) the oscillation is not being ramped although you can see the paths for each behavior in the keyframe editor.
I apply the Oscillate parameter to the X rotation of the text block.
IN THE OSCILLATION behavior inspector I apply a Ramp parameter to the Amplitude. I wind up with two Behaviors; Ramp and Oscillate.I’ve experimented with the settings to no avail. I’ve also tried stacking the Oscillate behavior above the Ramp behavior. I either get no movement or I get oscillation without ramping.
Any clue? I appreciate your help. Your reply has made me aware that I can put a parameter on a behavior that exists because of a parameter. Thank you for that.
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UPDATE: Got the amplitude to ramp but now I seek to ramp the Oscillate Speed. With just the amplitude ramp the swing was unnatural because the speed didn’t ramp up as the amplitude with each swing decreased. I’m on a quest.
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[Don Smith] “With just the amplitude ramp the swing was unnatural because the speed didn’t ramp up as the amplitude with each swing decreased. I’m on a quest.
“Then all you need to do is apply another Ramp behavior to the Speed parameter to increase it as much as you like over the duration of the animation.
Simon Ubsdell
http://www.tokyo-uk.com -
Actually, to be accurate, the oscillation speed of a swinging pendulum (your sign) doesn’t change over time. Physics nerds will cringe if you speed up the oscillation as the motion dampens. And it avoids the extra step of adding the ramp behavior to the speed.
If you want to confirm this, tie something to the end of a string and swing it, noting how long it takes to swing (heavier objects take longer and are thus easier to measure). You’ll notice that even when it’s nearly still and only swinging a few inches, it still just takes just as long between swings.
The same goes for a spring – the oscillation speed should not change as it dampens down, only the amplitude.
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If you want to achieve this with keyframes rather than behaviors, it’s not just the spacing of bezier keyframes that matters but the speed of each curve. I usually space out the keyframes as I want, then go into the keyframe editor and drag the handles of the middle ones to create the speeds I want. The curves will definitely end up differently than just changing the interpolation to bezier, as the attached image shows:
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[Justin Mrkva] “Actually, to be accurate, the oscillation speed of a swinging pendulum (your sign) doesn’t change over time. Physics nerds will cringe if you speed up the oscillation as the motion dampens. And it avoids the extra step of adding the ramp behavior to the speed.”
I thought of pointing this out but then I thought we’re talking about Motion Graphics here not the “real” Newtonian universe, and if Don wants the speed to increase there’s no reason why it shouldn’t – hence the tip for how to do it 😉
Simon Ubsdell
http://www.tokyo-uk.com -
It depends on the goal… if the motion graphics are intended to look realistic, then yes, you should try to stick with accurate physics as much as possible. In most cases, that’s probably the look you want to start with, especially if it’s actually the easiest option.
But you’re correct in that sometimes, either for a look or for complexity’s sake, you might want to take shortcuts. For the swinging sign, you could add an oscillate parameter to the damping value to more closely simulate variable damping with air resistance, which would be more accurate, but would also be an extra step that wouldn’t really make too much of a visual difference.
The correct answer? Do what works! 🙂
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