Slow down or speed up an animation?

Being very new to animation I’m having trouble with the speed I want my animation to move at. I’ve found out the hard way that if I just hit the play button while in Blender it doesn’t show the animation at the same speed it will move when rendered.

I’ve tried to judge how fast my animation will move by math.

At 24 frames per second I know if I change the pose every 24 frames it’ll take a second to make that move.

If I make a key frame at every 12 frames that’ll be a half second.

Yet I still misjudge and things and they wind up moving either faster or slower than I want them to. Is there a way to add frames in between key frames to slow things down or remove frames to speed them up?

If not is there a better way to do it?

Easy using the dope sheet just select your keyed frames and move to desired location…

Have you tried pressing Z in the 3D view to go to wireframe view before running the animation (Alt+A)? Blender will often be able to run it at full speed in wireframe mode, and you can still see how each objects moves.

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For an even more reliable playback “at speed,” switch to the bounding box view. It’s very abstract but can give you a better idea of the actual playback pace if using wireframe mode is still too slow.

In terms of adjusting a particular object’s animation speed, the simplest way is as mentioned, just grab some keys in the DopeSheet or Action Editor and drag them so the start & end of your action brackets fewer frames. But you can do this with more efficiency & accuracy as well by scaling a set of selected keys. The frame indicator acts as the “pivot” point for such scaling.

For example, say you have a ball-bounce that takes 5 seconds and want it shortened to 4 sec. In the DopeSheet or Action Editor (or even the F-curve Editor), grab all the keys in that sequence, place the frame indicator at an appropriate place on the Timeline (often on the first frame of the sequence), then use S-KEY (for Scale) and type 0.80 for the scaling value. The selected key sequence will then shorten to 4 seconds (5 x 0.8 = 4) with all the keys in the sequence being adjusted proportionally. Making a sequence longer just means scaling by > 1.0

In the F-curve Editor you can make things go “faster” but keep the same sequence length. This is done by adjusting the slope of the animation curve(s) for an object. The steeper the slope (which is a relative thing given that you can adjust the view so freely), the faster the object will perform the transform you’re adjusting.

For example, a fan’s rotation over a given set of frames (say 24) can be sped up by increasing the slope of the f-curve for the rotation axis on which the fan spins. If the first frame is at 1 and the last at 24, grab the key at frame 24 and drag it in Y (“up” for a positive slope and “down” for a negative slope) in the F-curve Editor. You’ve increased the amount of rotation per frame (that’s what the Y-axis is for, it denotes the value of the key you’re moving) and thus the fan spins faster.

Note about slope adjustment – slopes can be positive or negative, so the direction in Y that you drag a key is dependent on which way the slope runs to begin with. If it’s a negative slope (Y values decrease with time so the slope is going “downhill”), you’ll want to drag the Key in negative Y – “down.” For positive slopes (“uphill”), drag the keys “up” in positive Y.

Also in the timeline menu you have the option to force dropped frames so the animation will run in real time.

Thanks guys! That did the trick. I did the select, grab and move in the dope sheet, so simple.

@chipmasque I tried the technique you talked about using the scale and 0.8 but I must have done something wrong because nothing seemed to happen :-/ I’m sure it’s because I have no idea what I’m doing. I’ve been playing around with Blender for a while now but this is the first time I’ve tried animating. So much to learn…

I will try the wire frame mode in the future to get a better idea of speed. That’s a good idea too!

chipmasque & Richard cool stuff in your sigs!

is anyone still on here? if so can you help me, I need it ASAP for school!!!