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Fixed in 2022.2.X

Fixed in 2020.3.X, 2021.2.X, 2022.1.X



Found in





Issue ID




HingeJoint2D reactionTorque is Zero AND Joint Break Torque does not exceed threshold.



Reproduction steps:
1. Load the attached "" and open the "TestHinge2D" scene.
2. Select the "LongBox" GameObject.
3. Observe the "Test Hinge Joint 2D" script ("Torque", "MinTorque" & "MaxTorque" Properties)
4. Observe the "HingeJoint2D" component ("Break Torque" Property)
5. Enter Play Mode

Expected result: Torque is non-zero and likely negative. The minimum torque exceeds the HingeJoint2D Torque Break Limit (1000) which should destroy the HingeJoint2D.
Actual result: Torque is 0 therefore the minimum torque never exceeds the HingeJoint2D Torque Break Limit (1000) so it is not destroyed.

Reproduced in: 2020.3.14f1, 2020.3.23f1, 2021.2.5f1, 2022.1.0b1
Not Reproduced in: 2019.4.33f1, 2020.3.13f1

  1. Resolution Note (fix version 2022.2):

    This was caused by upgrading the latest Box2D b2RevoluteJoint (used for the Unity HingeJoint2D) to fix the following case:

    Unfortunately this came with a Box2D bug which has now been fixed and applied to Unity. More details on the bug can be found on the Box2D GitHub site here:

    This is now fixed on Unity Version 2022.2.0a1

  2. Resolution Note (fix version 2022.1):

    This is fixed on Unity Version 2022.1.0b3

  3. Resolution Note (fix version 2021.2):

    This is fixed on 2021.2.8f1

  4. Resolution Note (fix version 2020.3):

    This is fixed on Unity Version 2020.3.26f1

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