Animations look different in preview than in game mode or in a single key frame

Hi everyone,

right now we are dealing with a strange issue, affecting only the preview mode of the Unity animator:

If we compare the preview mode (hitting the play button of the animation tool) with the actual keyframes, the movement of the character will look a lot different than viewing each key frame separate by moving the cursor of the timeline manually.

Current behaviour:
- When viewing the animation preview mode, all animations look very different compared to their keyframes
- it looks like the transforms of the IK chains won't move smooth along with the bones that they are attached to, but keep stuck at wrong positions, influencing their bones behaviour in the wrong way
- When selecting a single key frame, the animation looks normal an the IK solver's transforms will travel to their destinated coordinates

The animations look completely normal when viewing them either keyframe by keyframe or when they are triggered in game mode. This only affects the preview of the animation window in scene mode. The IK solvers are shown in a total different position than they are supposed to.

We have also created a GIF in order to show the difference. You can clearly see the different movements of arms and legs due to the different positions of the IK solvers:


Expected behaviour:
- The animations should look exactly as they are configured within the keyframes when they are played in the animation preview mode
- IK solvers should move the same way as they are supposed to within their keyframes

Environment:
This behaviour can be expected in both Unity 2020.3.25 LTS with 2D animation package version 5.0.10 and also in latest Unity 2021.1 with 2D animation package version 7 on Windows 11.

Additional information:
The issue suddendly started to occur, without any modifications to the packages. Someday the issue appeared and has been resolvable by simply restarting the Unity editor for a few times, but it has now become a permanent issue, preventing our animators from doing their work because they can't properly use the animation preview.

Please also note that we have seen that there has been an fixed issue in version 5.0.8. of Unity 2D animation that sounds very similiar to our issue ("Fixed an issue where IK Solvers would not be updated when previewing an animation clip. (1364597)").

However, we actually had these problems beginning way later and we are currently using a version in which that issue should be actually fixed.

Thanks for your help in advance!

Kind regards,
Christian

 

Hi @Ted_Wikman and thanks for your response.

This has also been my first thought. You mean it might be caused by animating both the transform position or the IK solver and the transform position of the bone that the IK solver is attached to in separate keyframe properties?

But even if that's the cause, I don't understand why:

• The animations still looks perfectly fine in Play mode
• The single keyframes look as expected when scrolling through the timeline
• The issue started to occur randomly and it was possible to avoid the wrong behaviour at first sometimes by simply restarting the Unity editor, before it has become a permanent issue
• Even older animations that used to work perfectly fine for over a year now are suddenly broken when playing their preview, even though we didn't make any changes to them

All the points described above speak for an issue with the Unity editor from my point of view. The position of transforms should always be the same in the Animator preview like it's in play mode or when viewing a single keyframe within the timeline. If they suddenly don't match with each other anymore, I assume that this is a graphical issue of the Unity editor.

We have also submitted a bug report, I can send you the link via private message.

Thanks for your help and best regards,
Christian

 

Hi @Ted_Wikman, many thanks for the quick reply! I wrote you a private message with the fogbugz URL to the related bug report.
In the meantime, I'll try to figure out the current IK set-up with my animator team and if the combination of IK solver and bone position that you have described is also the case in our project.

 

Note: We just did a rollback to Unity version 2020.3.17 and downgraded the 2D Animation package to version 5.0.7. Using this version, all animations look like they did before in the animator preview.

I therefore assume that this fix in 2D animation package ver 5.0.8 (highlighted in the screenshot below) has something to do with our issue:

 

Hello,

I'm experiencing the exact same issue, and I submitted a bug report for it around 3 weeks ago. I just got an update on that bug report with this reply:
---
Hi,

Thanks for getting in touch, we actually know about this and you can check the status here:
https://issuetracker.unity3d.com/product/unity/issues/guid/1387137

The is by design. When animating IK, affected bone transforms should not be individually animated. This will cause the two systems (Animation and IK) to fight each other over the final bone transform position. The fix is to either choose to animate using IK or keying individual bone transforms.

Please reach out to me if I can answer any questions or be of further help.

Thanks,
Ugnius
Customer QA Team
---

I've already replied to this, but it took 3 weeks to get a reply to my ticket last time, so I'm making a post here as this is extremely concerning.

I already explained this in my report, but animating any bones that change the position of anything in the chain breaks preview playback (the pelvis affecting leg bone positions for example). It's not just animating bones in the chain.

This behavior is clearly not by design. The animation works correctly everywhere except during preview playback (runtime, manually looking at frames, etc).

If you could provide some additional information on this, I would greatly appreciate it @Ted_Wikman

Thank you.

 

Thank you for your reply @Ted_Wikman

I apologize if I'm coming off as impatient; I've had to work around this bug for weeks, so I was a little shocked when I read that it wasn't going to be fixed.

It's very simple to reproduce. Here is a video showing the bug in action: https://drive.google.com/file/d/1sbdC67v8P4cK-64Ag7G6lCqxE3yc4sR-/view?usp=sharing

The only bone being animated in the video is the pelvis, and the IK looks different during preview playback compared to runtime. There is no special setup, I'm just using a few bones with a single Limb chain.

This behavior is very problematic for me, as I'm unable to preview what an animation actually looks like, which makes animating very difficult and much more time consuming. The video may not look like a big deal, but the result can get much worse with more complex animations.

Here is the zipped project I was using in the video: https://drive.google.com/file/d/11YmiuuKmrjGMmf7onGB3KZHJJdPC0GHv/view?usp=sharing

If you require any additional information or files, please let me know.

 

@terovania_cschaal found that 2D Animation 5.0.8 is where the bug first appears. I can confirm this. Testing on 5.0.7, everything works and the bug is nowhere to be found. Updating to 5.0.8 immediately introduces the bug.

Here is a video of 5.0.7: https://drive.google.com/file/d/15BrAjzz06gmZCKsWq5vcp9uU7rE7tsJ6/view?usp=sharing

I animate the pelvis, as well as the hip bone (which is a bone in the IK chain), and it still works perfectly. Something changed in 5.0.8 seems to be the cause of the bug. Hopefully that helps narrow it down @Ted_Wikman

I also tested Unity 2019.4 and 2021.2, and the bug was not present in 2019's IK package (2.2.0-preview.1), but it was present in 2021's 2D Animation package 7.0.3.

 

Thanks for the update!

I'm not in dire need of the fix, but I'll be looking forward to when it's officially released.

 

I saw that the fix was going to be in 5.1.1, but didn't realize that it was live already. I just updated my 2D Animation package and it's working great!

Thanks for the update, and thank you for fixing this!

 

Thanks for this Thread, I have the same problem. I use the Unity-Version 2020.3.25f1 and I cant update the Animation2D package to 5.1.1 because then I get this Error Massage:
"Library\PackageCache\com.unity.2d.common@4.1.0\Runtime\InternalBridge\InternalEngineBridge.cs(21,35): error CS1061: 'SpriteRenderer' does not contain a definition for 'IsUsingDeformableBuffer' and no accessible extension method 'IsUsingDeformableBuffer' accepting a first argument of type 'SpriteRenderer' could be found (are you missing a using directive or an assembly reference?)"

And I cant downgrate because it doesn't show it in the package manager.
What can I do?

 

Hello @Ted_Wikman and thanks for the reply!
Unfortunately I can't download the newer version right now (I have storage problems), but I just made a new animation and oddly enough now it works fine. The problem probably will occur again, but for now it is good. But I will keep this post in mind.

Thanks!

 

I seem to be having a very similar issue with 2020.3.33f1. Playing scene results in a totally different transform than the preview. The preview doesn't seem to be taking the location of my game object into account, but it works fine when I play the scene.