Use HingeJoint

Unity Engine
1

Hi everyone,

I have a problem with the hinge joint component.
The variable ‘angle’ (hingejoint.angle) returns a strange value.
I have two square, the first one has the hinge joint who target the second one.
When I rotate the first one, the variable ‘angle’ change but the squares are always aligned.

Before rotation:

5505316--564640--upload_2020-2-21_12-14-51.png
5505316--564640--upload_2020-2-21_12-14-51.png754×481 33.4 KB

After rotation:

5505316--564643--upload_2020-2-21_12-16-17.png
5505316--564643--upload_2020-2-21_12-16-17.png650×506 32.9 KB

2

Not sure what, if any hierarchy here is, but make sure you’re not placing them in a hierarchy with one as a child of the other. Also, when you say, “When I rotate the first one”, make sure that isn’t you just modifying the transform because that isn’t a physics-friendly operation; it’s just instantly changing the poses and bypassing physics. Physics only works when you go through the physics APIs to change poses so use Rigidbody.MoveRotation etc.

3

Thanks for your answer.
There is no relation parent-child between the squares.

5505625--564721--upload_2020-2-21_13-54-23.png
5505625--564721--upload_2020-2-21_13-54-23.png845×290 6.35 KB

I changed a little the project.
I have a game object with 3 children: 1 corpse and two squares.
If I use the motor of the first hinge joint, my angle between the squares changed when he should be 0 degree.
I don’t use a move transform or others, just the motor component.

4

Maybe you can show this “angle between the squares” better. The images above don’t show anything really. Maybe show the inspector or more details, maybe a video.