I upgraded our 4-year project from Unity 2019 to 2021 LTS and noticed that some hinge joints are broken with incorrect limit ranges.
After digging into it, I found that in Unity 2019, the angle of limits was relative to the “static” rigidbody, regardless of whether the attached one or connected one is static.
However, in Unity 2021, it is relative to the “dynamic” rigidbody. This means if the attached rigidbody is static and the connected rigidbody is dynamic, the limits follow the connected body.
Why was this change made? It could potentially break all levels that use hinge joints in any project…
Comparison:
Unity 2019: Imgur: The magic of the Internet
Unity 2021: Imgur: The magic of the Internet
(Scenario: The hinge joints attached on static rigidbody and connected with a dynamic body.
Rotating the static body.)