Rotation animation slows down towards the end, towards approaching the keyframe

Support Animation and Rigging
1

Hi, first time animating in blender. I’m animating a little UFO and i’d like it’s ‘body’ to spin in a constant loop. Tho when i set a keyframe, for example set its z axis to 180 degrees, it spins quickly but slows down massively towards the end. For some reason its now seemingly doing two quick full rotations towards the beginning then slows down towards the keyframe?

I checked the graph editor and the Object Transformation graph looks like this:

image_2023-12-07_200947529
image_2023-12-07_2009475291490×858 256 KB

What can I do to have it consistently spin in a loop?
Thank you!

2

In your graph editor, select all with A. Press T and choose Linear

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3

Hi, I’ve deleted the old animation and made a new one, set a keyframe at frame 20 and gave the Z axis the rotation of 180 degrees, the graph still looked and behaved like this so I followed your advice and this is what happened:

image_2023-12-07_202316461
image_2023-12-07_202316461938×868 171 KB

It still doesn’t behave how I wanted it.

4

Changing the rotation mode will help when you want to do full rotations.

Quaternions behave very differently to Euler. Euler is conceptually more like what you imagine when rotating around one axis.

Try changing the mode from Quaternion (WXYZ) to one of the other Euler options.

(You’ll still want to change the graph to linear to get the constant rotation speed)

5

Thank you! It’s rotating seemlessly : ) Made a new animation with a keyframe set at 20 frames and the z axis set to 360 degrees, though the ufo is doing several full rotations before it reaches the frame, how can I have it that it only does one? Thank you!

6

Depending on your frame rate, 20 frames is quite fast for a full rotation. Maybe it just looks like it’s doing more turns.

How does it look if you step though one frame at a time (using the left and right keyboard cursor arrows)?

If you’re able to upload the file, I can take a look. You can replace the ufo with a cube if you like.

7

Hi, i checked frame by frame and you’re right, it just looked like it was spinning more than once. Thanks for helping me out!

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