View Full Version : Head joint flips when a animation clip is applied.

03 March 2010, 08:58 AM
Head joint flips when a animation clip is applied.

I created a rig then made a Character for it, then I animated several animations for it. 4 to be exact. When applying the clips two of the four clips gave problems making the head cave in on the body. The problem is as follows: When the animationclip is applied the top 4 joints leading to the end joint (named the head joint) seem to be in the same place. When examining the animationclips that gave the problems I found some keys on the scale and the transformation channels of these last 4 joints leading to the end joint. After correcting the problems I still had the problem with those clips. What can I be doing wrong.

Kind regards,


03 March 2010, 02:48 PM
usually the problem can be seen when looking at the graph editor. take a look a the Curves for those clips of animation the head joint in particular. You will more than likely see the spike in the curve fairly easily.

Break the tangent on both sides of the curve section that is causing the issue. Set the tangets to linear or flat (youmay need to experiment a bit).

What this should do is keep the curve from dropping or popping above or below the 180 degree mark which is generally what causes the flip in animation. Since Maya uses Euler angles (180 degrees Min/Max) to derive the rotation of an object/node.

You can also switch to Quaterion Rotations (A rotation based Matrix) in the preferences, which should also help out with the flipping.

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03 March 2010, 02:48 PM
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