Keyframe confusion

[Kevin O’neill]

Hi Jeremy,

I wasn’t able to open your link, but it sounds to me like you’re suffering from the dreaded boomerang effect. Aharon Rabinowitz has 2 tuts all about it, you can find them here:

https://library.creativecow.net/articles/rabinowitz_aharon/boomerang_1.php

and here:

https://library.creativecow.net/articles/rabinowitz_aharon/boomerang_2.php

hope that helps

[Darby Edelen]

My recommendation is to enable ‘Default Spatial Interpolation to Linear’ in the General panel of your preferences. However, this will only apply to future keyframes that you create. You can change the spatial interpolation of your already existing keyframes manually by right clicking on the keyframe and going to ‘Keyframe Interpolation…’ then changing the value of ‘Spatial’ to Linear. Alternatively you can use the pen tool to adjust the Auto Bezier handles that AE created when you made your keyframes.

Darby Edelen

NVIDIA
Santa Clara, CA

[Jeremy Mullen]

I’ve been dancing between raindrops apparently for almost ten years; sure enough, I was a victim of the Boomerang effect – only I’d never run into it before…somehow. Just goes to show that when you think you’ve been through every possible situation, you’re still always a beginner.

The problem also concealed itself a little because it was affecting many, many layers which, when viewed in the graph editor, looked like a recently-strummed set of guitar strings going every which way. I could only Toggle Hold Keyframe one layer at a time, so I needed to switch them off and go through them systematically before I could see any correction. Before, when I had been toggling, I might have fixed one layer, but couldn’t tell because of the rest of them getting in the way.

Many thanks to all.

[Darby Edelen]

[Jeremy Mullen] “The problem also concealed itself a little because it was affecting many, many layers which, when viewed in the graph editor, looked like a recently-strummed set of guitar strings going every which way.”

Just another note to really drive home the issue:

The graph editor is for editing temporal interpolation, and it really sounds like you’re having issues with spatial interpolation which can be edited on the motion path itself with the pen tool (g).

You may already have an understanding of the difference, but if not I recommend you get to know it and love it (as much as it’s possible for one man to love two very different forms of interpolation… maybe I’ve been doing this for far too long).

Darby Edelen

NVIDIA
Santa Clara, CA

[Jeremy Mullen]

Darby-
Absolutely right, but the catch is that the very small wiggle is virtually invisible when viewed on the motion paths, since it oscillates tightly around the keyframe, and it’s value was less than 2 points. Only in the value graph editor was it visible, and only when zoomed way way in on the vertical axis.

And I like to think that I love all interpolations equally.

[Darby Edelen]

[Jeremy Mullen] “And I like to think that I love all interpolations equally.”

Ah, an equal opportunity interpolation admirer 🙂

Although the ‘wiggle’ was very small it is still very easy to fix using the pen tool on the motion path (or the Keyframe Interpolation… dialog for the keyframes).

The whole reason there is a wiggle to begin with is because AE has automatically guessed at the best bezier path (Auto-Bezier)… the pen tool just gives you the ability to set it straight (so to speak).

Also, I hope you take my recommendation to set the ‘Default Spatial Interpolation to Linear’ preference in your General preferences. This will stop AE from guessing at bezier curves, but still leave you with the ability to specify them later with the pen tool.

Darby Edelen

NVIDIA
Santa Clara, CA