I ran across an interesting little trick yesterday. Normally on rigs you will create controls out of something like splines, and use that to drive a joint to which your character is skinned. To pull this off, usually you will parent your joint under a control, or point-orient-scale constrain the joint to either your control or a null (empty group) under your control. Sometimes you’ll have two complete heirarchies, one for joints and the other for controls.
Now if you are constraining a joint between multiple controls (for IK/FK switching for example), then you have to have the bones and controls separate. But if you are doing a simpler rig (such as for a prop) that uses joints and you don’t want to turn on the handles for the joints (because little plus signs in the interface all blend together) then there is another option available.
Create your spline shape that will control a joint. Select the Shape node of that spline. Now add the joint-to-be-controlled to the selection. Now type “parent -s -r” in the MELScript window (minus the double quotes). This will reparent the shape to the joint instead of having it under a transform null. The fun thing is that when you select that shape in your interface, Maya will actually redirect the selection so you are selecting the joint! You can go into component mode and rotate/translate/scale the control points as desired to get your control shape in the right place.
Does anyone use this technique? Any downsides?