Odd in-game mesh deformation animation behavior

Hi, I’m trying to make an animated mesh deformed key from a keyboard for a UI interaction prompt. With how the armature was set up I had to animate it through intense stretches. Obviously while doing this it changed the position drastically which I simply corrected by moving all the bones to make sure the part stayed in the same place. It turned out like this which had the cartoony effect I desired:

However, it behaved differently once the animation was running under a WorldModel. It was bobbing up then down and not staying in the same place, which I assume may be a Roblox issue. It also seems to be changing position in relation to the armature proportions.


The position property of the meshpart and bones were constant the entire cycle, so it had to do with how the animation had rendered it. As you can see the part still deforms as it’s intended to, however, the bobbing up and down is unintentional.

Eventually, I had given up finding the cause and tried changing the position to inversely match where it seemed to be going. I estimated the plot points and created a rough equation to match it.

This mitigated its range of motion a little however this wasn’t enough (not to mention the extra wobbliness).

I am wondering if anyone knows whether this WorldModel mesh deformation behavior is a Roblox issue or my fault. I can’t afford to spend any more time manually making an equation to change its position so it doesn’t look as bad.

Hmm, seems to be a bug then assuming the model is exactly the same as the animation which it should be.

Have you tried this fix with parenting it to workspace then back?

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Unfortunately, this did not work for me. I tried setting the parent to workspace beforehand and no luck. After that, I tried a wait() before setting the parent from workspace to WorldModel however that didn’t work either.

I just made code that ran the animation on two buttons under the workspace, one client-side one server-side. Apparently, they were also bobbing up and down which I should’ve checked earlier. It appears this isn’t a WorldModel related issue, it just behaves like this in-game. Though, in the animation editor though it acts fine which confuses me.

Fixed. I went into the animation editor and set the first keyframe column to a linear easingstyle instead of cubic.