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Votes

0

Found in

2022.3.63f1

6000.0.50f1

6000.1.6f1

6000.2.0b4

Issue ID

UUM-107967

Regression

No

Animation does not control the property of the Gameobject when the keyframe and initial value are the same

-

How to reproduce:
1. Open the “TestProject.zip” project
2. Open the “SampleScene”
3. Enter the Play Mode
4. Select the cube GameObject in the Scene view
5. Try moving the GameObject

Expected Result: The cube cannot be moved
Actual Result: The cube can be moved

Reproducible in: 2022.1.0a1, 2022.3.63f1, 6000.0.50f1, 6000.1.6f1, 6000.2.0b4

Reproduced on: Windows 11 Pro (24H2)
Not reproduced on: No other environment tested

Workaround: Disable and reenable the parent GameObject

Notes:
- If the starting and ending position keyframes are the same, it will not contain the object in that position
- If there’s even the slightest discrepancy between the two keyframes, this will not reproduce

  1. Resolution Note:

    Hi,
    This isn’t a bug, it’s actually an optimization feature in Unity’s animation system.
    Unity uses Constant Clip Sampling Optimization to skip constant keyframes if the object’s starting position matches the clip value. That’s why the cube can be moved when the starting position matches the animation. If the starting position doesn’t match (e.g., moving the cube and THEN disabling/re-enabling the parent), the animation locks the cube in place because the constant optimization is ignored.
    Workaround:
    If you want the cube locked no matter what:
    Click on the GameObject with the Animator component.
    Look at the Animator in the Inspector.
    Switch the Inspector to Debug Mode:
    Click the three dots in the top-right corner of the Inspector (it’s set to Normal by default).
    Select Debug.
    Back in the Animator component, you’ll see new options. Set Allow Constant Clip Sampling Optimization to false.
    Alternatively, tweak the animation clip by adding a tiny difference between the start and end keyframes to disable the optimization.
    Let me know if you need more info!

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