some rigging questions

#1

I have my model all rigged and moving nicely. however i have this little trick that im trying to pull off…

basically, i have a control object that im using to drive the IK of an arm.

however i want to still retain control of the hand independent of the arm. So im using an align expression to lock the roation of the wrist bone to the rotation of the control null.

However, im trying to setup something a bit more elegant, i want my hand to be always aligned with the vector of the forearm, however i still want to retain the control of the wrist using the same control object.

Basically, i want to be able to move the arm IK goal, yet i want the hand control object to always stick to the end of the forearm and align to its vector, while still having the ability to rotate it in order to orient my hand.

any suggestions? its a pretty intricate setup i guess, but i want to eliminate as much tweaking as possible. thanks in advance.

#2

Not sure if understood this correctly, but you can have the hand part of the arm hierarchy, so that it follows its parent’s i.e. the forarm’s rotation, and then set up a couple of expressions that add (+) the goal orientation to the hands orientation. Is this the behaviour that you are looking for?

#3

yea BUT i also want the arm handle to always stay attached to the end of the forearm. and act more like you are ROTATING the arm rather then MOVING the goal around.

#4

Is the LockedGoal function what you are looking for…?

#5

lol probably.

now i have another problem.

my feet, naturally dont have the control object located at the leg effector… so how can i introduce an offset into that function?

#6

Errr, by making a null the child of your control object, offseting that null to your effector and using this as the goal? :slight_smile:

#7

ah. but that wont prevent me from “tearing” my control object away from the limb it controls. id like the controller to basically stay glued to the limb it controls.

#8

can you link the scene?

i also have some question about that, i whant to make the ik and the hand move like in LW,
set goal oriented and the hand move as i move the null goal, but how is if i whant to set and IK on/OF slider, i can do it for the IK but i cant set it right for the rotation of the hand , i use align expresion but i cant fade it =]

#9

sorry but the scene is a commercial asset :frowning:

#10

Get Mark Wilson’s DynamicFunc expressions from here :

http://www.zoogono.com/plugindetail.cfm?pid=30

" These are dynamic versions of MoveTo and Align, plus a dynamic IK limit func which is good for Motion Dynamics and more complex IK rigs. Finally, with MW_Vertex_Attach you can move objects to mesh vertices!
Each one has a description of what it does when you select it to use it in the command tab "

I haven’t used these in a while, so I expect they’ll still work with the latest realease.

#11

i use them, but dont know why i got a weird direction on the hand, maybe i aling the null bad from the begining on the setup tab

#12

Mark’s Dynamic Align function doesn’t always work the way you’d expect it in some situations. Alternatively you can use the good old Keyfader function, it can actually act as a dynamic switch for any function :slight_smile:

#13

thanks for all the help. i think i managed to get mr santa to a happy place. i have some other ideas for limb interaction anyway, but thats for another time.

#14

i try with dynamic align
but when i move the goal null from place, the hand still rotate acording to the IK, (like there was no expresion) or in LW, not seting the goal oriented.

any ideas?
thanks for the times guys

#15

You may check your expression order, as well as the IK solving order.

#16

maks thanks, i all ready check that and nop,
even do i play a lot with the order of the expresion and the before after IK, still dont getting it, i will set a scene to show later on, =)
i apreciate the time

#17

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