Is it possible to use Avatar Center as a bone with Rigged Mesh?

[Minareth Irata]

As the topic title says: Is it possible to use Avatar Center as a bone with Rigged Mesh? I wonder this as it does have some useful applications, like a balloon of which the balloon itself with a cord is rigged to the Avatar Center and the other end of the cord to one of the hands. Completely defeating the need for scripts, particles or flexi prims which rely on sim and client performance.

[Chosen Few]

I'm not sure what you mean by "Avatar Center". The way you've got it capatilized, it sounds like a place, as in, "Hey man, have you been to Avatar Center lately?  I hear they've got some cool stuff over there."

I take it you meant to say "the avatar's center", as in the middle of he avatar's body?  I'm still not sure exactly what that might mean, either, though, from how you worded the rest of the question..

The center of the avatar, just like the center of a real human being, is the pelvis.  If you're asking if you can weight part or all of a bound skin to the pelvis bone, the answer, of course, is yes. 

Anything so weighted would remain rigid and unmoving, relative to the rest of the avatar body, as the various body parts animate.  The only thing that could cause it to move would be animations that translate or rotate the body as a whole, like lying down, or doing a cartwheel, or falling over, for example.

I'm having trouble picturing how your balloon scenario would work.  You could certainly make the balloon stationary, as described above, and weight the other end of the string to the hand, as you suggested.  That would cause the string to respond to the avatar's hand movements, but the effect would not in any way resemble how a real string resonds to a real hand, nor how a real balloon responds to a real string.  Pulling on the string would merely cause it to stretch, as the balloon would remain in its fixed position, relative to the avatar.  The balloon would not be able to bob up and down, or travel laterally, in response to the string pull.  It would look pretty ridiculous.

Also, if the avatar were to lie down, or fall over, or do anything else that rotates the pelvis, the balloon would rotate with it.  Turn the avatar upside down, and the balloon would be below it, instead of above it.  It would not be able to stay upright, relative to the world. 

Maybe you meant something else?  If so, please explain.

[Minareth Irata]

Avatar Center is an attachment point on the Avatar, I'm may be wrong and Avatar Attachment Points are completely different from Bones/Armatures. But anything attached to the Avatar Center does not move with the Avatar's Animation, only with the position of the Avatar. So say the Avatar Center could be used, even if the Avatar lies down, the object connected/attached to the Avatar Center remains where it is.

[Ivanova Shostakovich]

   That attachment point is handy. If you want an attachament that makes little birds fly around you, or whatever, attach it to Avatar Center and the rotating birds axis doesn't swing wildly away from Z while you move around. It was something I wished for five years ago.

[Chosen Few]

Ah, thanks for clearing that up.

I believe there is a way to use attachment points, as well as collision volumes, as pseudo-bones, for rigging.  It's complicated to set up, though, from what I've read. 

Given your description of how the Avatar Center behaves, I'm not sure it's the same kind of attachment point as the others.  It seems more likely it falls above the rest of the avatar in the scene heirarchy.  If that's true, then it would be unlikely that you could use it for rigging.  I'm just guessing, though.  Hopefully, someone who knows more about it will pop up.