Character Rig On A Rocking Boat

[loganb]

Ok this is a problem Ihave encountered a couple of times lately:

I have a craracter rig (from a client, not my own)

the character and several props need to be doing their thing on a moving surface, like a rocking boat deck for example.

If I parent the character rig to the vehicle, or parent both to a group, and then animate the rocking motion, the character rig begins to misbehave badly. Eyes float off of the head( fail to rock with the rest of the rig), limb rotations get all out of whack, it sucks.

I had to resort to animating the rocking motion into the character rig seperately from the vehicle rocking, which is an inaccurate hack and quiet painful if revisions are needed.

Is there a standard method of attaching a complex character rig to a movign surface or vehicle, one that will isolate all the character hierarchy's motion from the surface's motion, so that rocking the boat wont mess it all up?

[fortner_mike]

Maybe group all the character's parts and then parent the character's group to the boat?

[loganb]

It's the grouping that seems to throw the hierarchy off.

i think what is occuring is a multiple transform on hierarchy objects like eyes- the eye gets positioned by the rig, the rig is trasnformed by the group, and the eyes goes twice as far as it needs to, sliding off the head.
maybe i need to be more selctive about what I include in the group (i.e, only rig controls and no geometry or joints) but it's diffcult when things like eyeball are parented to the rig.

It really seems like a problem that would be quite comon and thus have a common solution...