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Hinge joint issues

Discussion in 'Physics' started by MaartenEl, Mar 13, 2019.

  1. MaartenEl

    MaartenEl

    Joined:
    Mar 17, 2016
    Posts:
    1
    Hello All,

    I'm trying to convert a CAD-assembly to a working unity rig.

    it's a relative simple hinged system: the upper arm is connect to the lower arm, the lower arm is connected to a baseplate (see image below).
    Using 3ds max design I aligned all the pivotpoints of the arms with the centre of the shafts.
    I linked the arms and shafts and imported it in Unity.

    Working from bottom-to-top in unity:

    1. I added a hinged joint to the lower pin with the baseplate as a connected body;
    2. Defined another hinge joint to the lower arm with the lower pin as the connected body;
    and so on.

    The baseplate has the 'is Kinematic'- function checked.

    now when I try to move the upper_pin everything goes haywire; the pins fly in a random direction and the arms start spinning like crazy.
    For all rigid bodies: 'Use gravity' is unchecked, collision detection has been set to "discrete".

    What am I doing wrong?
    When i link everything in 3ds max and apply a history independend IK-solver all works as expected but I can't get it to work in unity.