Search Issue Tracker

By Design

Votes

0

Found in

6000.0.58f1

6000.2.6f1

6000.3.0b3

6000.4.0a1

Issue ID

UUM-120442

Regression

No

Rotation values flip in animation when importing FBX with a generic rig

-

How to reproduce:
1. Open the attached “IN-117113” project
2. Open the SampleScene
3. In the Hierarchy window, select the "R_Up_leg" GameObject (Walk -> Position -> Pelvis -> P_Pre_Up_Leg -> R_Up_leg)
4. In the Animation window, expand the Rotation parameter
5. Observe the change of the Rotation.z parameter

Expected result: The bone’s rotation animation curve remains consistent and has a smooth change
Actual result: The bone’s rotation animation curve makes sudden 360-degree flips

Reproducible with: 2023.1.0a1, 6000.0.58f1, 6000.2.6f1, 6000.3.0b3, 6000.4.0a1

Reproduced on: macOS 15.6 (M1)
Not reproduced on: No other environment tested

Note: It causes the rotation to flip from negative to positive values, such as -173 to 172, in a single frame

  1. Resolution Note:

    The curves in the reproduction project have been imported as quaternions, and the Euler representation is only there to provide a human-readable representation of the rotation.

    The lack of unrolling here is as-designed, as the quaternion curves do not permit any rotation beyond the -180,180 range.

    Rotations are only imported as pure quaternions (not baked Eulers) when the rotation in the source file provides quaternion curves. If you wish to have Unity import rotations with unrolling, author your animation curves as Euler rotations in your DCC.

Add comment

Log in to post comment