To prevent flipping when a joint chain slides down its curve
This creates the spline IK handle with a parent transform node above the start joint. In the following steps, you’ll put the node on a motion path that prevents the start joint from flipping.
You can select the parent transform node by dragging a selection box around the start joint.
The parent transform node and its child joint chain move from the start of the curve to the end of the curve in the specified frame range.
If the curve has a 3D looping shape, you may also need to turn on Normal for the Up Direction to avoid unwanted flipping.
Now when you play the animation, the parent transform node and joint chain move along the curve path. The movement should be free of unexpected flipping. However, flipping is unavoidable if the path is very complex.