Basically I want to be able to parent constrain an object to an other object without flipping occuring. For example:

I want to parent constrain (thats the effect i want anyway) ChildA to ParentA. ParentA is parented under GroupA. It’s hierarchy would look something like this:

GroupA
....ParentA

ChildA
....(parentConstrained to ParentA)

Now, this works fine when i move and rotate ParentA. It also seems to work fine when moving and rotating Group A. However, further investigation (looking at the channels) shows that flipping occurs on childA when rotating GroupA past 180 degrees. This would mess up motion blur etc. It becomes really obvious when baking the animation and looking at the curves. Using Euler Filter whould fix this, but this is not always appropriate.

It also works in this case to parent constrain ChildA directly to GroupA, but not in a more complex hierarchy. Say for example I have a character rig, and I want to constrain the hat to the head joint. I want the hat in a separated hierarchy so I have the option to bake out the animation for just the geometry and export that without the rig. Now whenever i rotate the whole character, the hip, the spine etc I get issues with flipping on the hat. Rebuilding the characters hierarchy in order to get the correct rotations would be really awkward in this case.

I’ve tried different solutions (orient constraints, aim constraints, parent constraint) but they all result in flipping eventually. I’m using maya 2008 but I don’t think this is version specific. Anyone have any ideas?

This sounds very frustrating.
You may have already tried this, but the only thing that comes to mind right now is to
change the Interp Type of the parentConstraint to something other than “Average”.
“No Flip” seems like the best choice...but not always...try changing this value.
Hopefully this does the trick, but if not, I am stumped.
All the best with it.
~Ben

Yeah, I should have mentioned that I’ve already tried this. :) Doesn’t make any difference unfortunately.

And yes, frustrating indeed. Seems to me like such a basic thing that should work by default without any workarounds… But still, if there is a workaround I would be happy as well.