Solution to avoid Gimbal Lock for Twist Joints using Blueprint

Development Character & Animation
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Hi all,

As of may know, there’s not solution to avoid Gimbal Lock using Blueprints, so the alternative is to use C++.

I tried a different approach to solve this issue, and I came up with a working solution in order to solve Gimbal Lock when using Twist Joints.

On the left you can see the X hand_l rotation value flipping between -180 and 180, while on the right you see that there’s no flipping and the value goes over -180/+180.

The setup is as follow:

  1. If the value is >0 and <180 the data is read from the X hand_l rotation and I use a DoOnce to set a boolean to true.
  2. The boolean sets itself false and reset the DoOnce if the value is <0 and >-90.
  3. I then use a Map Range Clamped node, that gets the X hand_l rotation data, checking if the value is in range of -180 and -90, which then output 0 and 90.
  4. The output of this node is then added to 180.
  5. I then use the Select Float node to switch between the X hand_l data to the Map Range Clamp node output.
  6. Finally I scale the output by multiplying by a float ( set to 0.75 or 0.5 ) to transfer the rotation amount to the lower arm twist joint.

The same logic is used when the X hand_l rotation data is <0 and >-180.

Problem solved :slight_smile:

Regards,
Nicolas

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