View Full Version : IK_Folollow_Body............

02 February 2004, 09:41 PM
hi guys
l would like to know what is your technic about that........

let says l rig a arm with ik_handle and l want that ik handles be on/off like when l move my body the arm will follow it instead of be sticky at the place it is .............and off the arm doesnt follow my body like that l can get sticky arm and other way is like the same thing as a fk when u move ur body the arm move with it...................l got a solution in grouping IK and orient and poinconstraint ik to my clavicule but its a really long step l would like to know if some one got a smaller solution for that.........
sorry for my english :)
l hope lm clear BYe

02 February 2004, 12:27 PM
Yeah I'm having the same sort of problem as you but I don't have a solution at all. I've tried parenting then to the hip joint. Sometimes it works but then sometimes when I import the character to another scene the IK handles seem to just disapear. I find that they are there but they don't do anything. How do you make to handles follow the character but not dis-funstion?

02 February 2004, 04:07 PM
Parent the Ik handle to the "clavicula" joint...

02 February 2004, 10:10 PM
parenting ik_Handles cant work because let says u need in the same shot to to get the ik_follow and and 100 frame later u need to need ur arm be stiky on seomthing u cant animated parenting........................ill post my version of this little further.......................with group and point and orient constraint.

02 February 2004, 10:52 PM
Thanks for that. I ended up using the 'Sticky attribute' which was fine for the arms but then when I move the skeleton, all other IK handles like the feet for example stay stuck to the scene and not to the joint? I can't work out why they move with the arms but not with the other joints. thanks again

02 February 2004, 07:46 PM lock the arm on something, I then use a null object to which constrain the Ikhandle...a sort of dinamic pin

02 February 2004, 08:08 PM
No sorry, I don't want the arms to lock to anything. I want it to be a normal moving arm like the other body parts but the IK handles won't move. If I grab the hip joint to move the whole skeleton in place, some of the IK handles just stay in place and don't move with the body. I have made all the IK handles sticky so they stay with the joints. This attribute has worked for the arms so they move with the body but the feet still won't move and stay stuck to the scene where they were first made. Thanks for your help!!

02 February 2004, 10:11 PM
Well u often need cases where u might want your arm to stay put as u manipulate other portions of the body..
but to get the desired method u want .. i would suggest parenting the ik handles or its control object to the hip or the shoulder bones .. also u might want to creat another control object which is the highest in the hierarchy where u parent ur foot ik/hips etc to it so that u can use it to move ur model around..

02 February 2004, 10:57 AM
:cry: I tried what you suggested but when I parent the IK Handle to the joint that it was placed on, the handle disappears and the joints act as if they're on their own and not as an arm. Thanks for your help anyway I really appreciate it! Man this is hard work but I'll stick at it.

02 February 2004, 10:02 PM
Don't fret .. all things make sense as u keep chipping away at the shells of knowledge..

Comming back to ur problem perhaps I was not clear enuff..
the point is to parent your ik chains to joints or object to which it is not providing the iK solution.meaning u can't parent it to a joint if it is part of your IK solution.Look for maya's help for Ik solvers reference. It explains every thing you need to know.

When u creat an ik handle in maya u create two nodes : the Ik end effector and the Ik handle..

The Ik solver looks at the position of the IK handle and then tries to figure out how best to match its position with the endeffector.. for this the solver looks at the basejoint ( from which u are drawing the Ik chain) and the endeffector and tries to orient them so that they match the ik handles position in space..

The IK endeffector is the child of the first joint in the Ikchain.
By default the Ik handle isn't parented to anything

Thus this entire procedure is defeated if the Ik handle too becomes part of the hierachy since maaya goes in a loop. trying to orient the joints to the IK handles position and tries to make the Ik handle follow the position of the joint (since the ik handle is its child )..

solution is to parent the Ik handle outside of the Ikchain solution..
as mentioned if it is an arm u do not parent the Ik chain to its preceding bone.. u usually parent it to the hipjoint or something..

once u have parented the Ikhandles to the Hip joint u might want to create a locator which matches the position of the hip joint.. then u parent the hip joint to the loactor.. when u move the locator the hipjoint follows and so do the Arm Ik handles which are the children of the hip joint which is in turn the child of the locator.

u may also parent the feet IK chains to the locator so that u have one single ultra mega almighty omnipotent object with which u might move your rig around !

hope that was a bit more clearer !

02 February 2004, 09:14 AM
Thank you so much!!!!!!!!!!!!!!! You are a genius. I feel a bit stupid now because it seems so simple in the end. I'll remember your name and hope I can re-pay you one day. I guess I'll never forget how do do it now! Thanks again!!

CGTalk Moderation
01 January 2006, 12:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.