I'm having issues animating Trot's mouth. When I create two keyframes, something is causing it to go into step interpolation. You can see in the screenshot the play head is between two keyframes and the line is supposed to go directly from the left to the right, but it detours by going back to the zero line. Hard to explain but hopefully you understand. Any ideas how to fix it? Thanks.

This looks familiar. I don't recall how it happened or even if I solved it, sorry. Did you scale any channels by chance or could it be caused by two conflicting poses?

I haven't scaled anything. I've only been copying keyframes. In fact I've noticed this with Trot in the past, but this is the first time I've investigated it. Could it be rig related?

Hi Ken ...
That anomaly has been happening at least since version 12. I believe it happens when pasting keyframes but I'm not sure why it starts. I do know that once it occurs it will then randomly happen again and again for the keyframes associated with that particular bone after that. I think what I did was to grab a bounding box around the bad section of keys ... right click ... set "Interpolation Method" to spline or zero slope and I think that corrected it. I forgot if I deleted the unwanted keys first or not before resetting it through the interpolation method. I haven't used any pre-made rigs posted on here so it probably has nothing to do with the rig you are using. Sorry I couldn't be more help ...
Bruce

question -
someone else than KenH, please (he's swamped with SO): what is step interpolation?
google gives me photoediting; medicin; statistics and your usual 3D hazard, near-math-experience.
a:m gives me two hits that say nothing.

a newb-attempt; the second green key is not peaked, the channel recedes (moves to the left) along the y instead of plummeting straight down. that can give you a dance you didn't invite between the two previous keys.

Interpolation is how A:M determines the movement between keyframes. You have "Hold", "Linear", "Spline", and "Zero Slope". It's best to visualize by turning on the channel's editor. "Hold" will hold the keyframes value until it reaches another keyframe in which case it will "jump" to that value. "Linear" will cause the steps between to be like a straight line. So if you had something rotating on the X axis that starts on frame 0 at 0 degrees ... then rotates to -20 on frame 4 ... it would interpolate the following on the frames in between ... Frame 0 = 0: Frame 1 = -5: Frame 2 = -10: Frame 3 = -15: Frame 4 = -20 ... "Spline" tries to smooth out the movement by gradually starting and then gradually stopping. How it rotates depends also on the keyframes found before and after ... those keys also have influence on the curve. So with "Spline" you may go from Frame 0 = 0: Frame 1 = +10: Frame 2 = -7: Frame 3 = -28: Frame 4 = -20 ... again depending on what keyframes are also around them. "Zero Slope" tries not to let the values go beyond their keyed values but still tries to create a smooth transition. So Frame 0 = 0: Frame 1 = 0: Frame 2 = -10: Frame 4 = -19: Frame 5 = -20 ... Again it depends on the keys surrounding them.

I may seem confusing at first ... and I hope I got things straight myself ... but once you work with them it becomes easier. Again the channel editor is the best way to visualize the curves ... the interpolation ... between the keys.

Bruce

Here's what's happening:

It only happens with Trot.
It only happens with copied keyframes.
It's like there are two sets of keyframes on the one frame. I think this is because I copy two bone keyframes. But as I say I do this on other models with no problem.

I tried those things Bruce, to no avail. Thanks anyway.

At least Trot isn't in this shot too much.

thank you Bruce with cute avatar, and sorry for the off topic!