How to Move a Joint Rotation Center While a Bone is 'Live' (Bound)

i’m working in blender with the avastar add-on (for those who know what that is, and if it makes a difference).

so i have a mesh object, and i have a bone rig, and i painted bone weights and blah blah blah. it has a jaw bone (it’s not a human, it’s a dolphin, it has a long jaw). so i stuck the “hinge” of the bone where i thought the jaw should rotate from. however, in practice, i find that it is off, so i want to move it.

they (avastar people) told me the only way to move the position of the end of the bone (the ‘head’ or ‘hinge’ or ‘rotation center’) was to unbind the rig from the mesh, move the bone, then re-bind it.

is there not a way to edit the position of this rotation point while the bone is still ‘live’ and bound to the mesh? so that i can, for example, close the jaw and see if the front of the jaw is meeting the front of the muzzle, and if it is not, then move the rotation point around until it does? (i ask, because i can do this in poser, and it is SO HELPFUL.)

Unfortunately, you can’t reposition a bone in pose mode. I don’t know much about the avastar addon (is it for editing meshes from that online game?), but you can try to move the bone in edit mode, re-adjust your weight maps, if needed, then switch over to pose mode to see if it works. I would only unbind the mesh if things looked wonky after moving the bone in edit mode.

I agree here. I was looking over the docs to see if they had a special definition of “binding” and it seems to be the same as Maya which is basically the same as Blender auto weight assignments. So you are probably OK to move the bone a little in Edit mode. Unless they are doing anything special in Binding with the controllers. Thing you would worry about mostly - lets say you were using rigify - is that if you move that bone, the autorigger would have expected the center to be in a different place (in relation to the complex controls that are set up) and you’d want to regenerate the rig. This might be a factor here as well. But it is hard to tell from the docs.

thanks guys!

avastar is for making avatars for second life, yes.

and i think that’s the first thing i did: went into edit mode to move the position of the bone, and the whole mesh went fubar. :X
i think the problem lies in the complex multiple bone-set rigging. there’s deform bones, attachment bones, physics bones, and then the pose bones, and if you touch the wrong thing, you’re screwt. though maybe i can try again and make sure both the pose and deformation bones are moved. (why is this reply box not word-wrapping?)

okay, i was done with blender kicking my butt today anyway, so i went and tested it.
it doesn’t work. one nudge of one or both of those bones in edit mode, while still bound, and the whole mesh blows up. like… literal explosion, vertices everywhere…

but as an ancillary question… i posed the jaw, with the jaw pose bone. but when i switched from pose mode to edit mode to move the bone/hing/rotation point, the mesh went back into its default position/shape. what i really wanted was to move the bone hinge while the mesh was posed. you know how you can edit the mesh while it is posed? with those… buttons? (they’re in the add modifier panel.) is there a way to do that while editing the bones, the same as doing that while editing the mesh? y’know?