Rigging Problems - IK/FK Translation and Rotation

[sorarey]

Hello there!

I'm having a hard time with maya 2011.

My team is doing a student project and I got the lovely task to rig the charakters.

http://img3.myimg.de/Rig0bf46.jpg

First problem is the Polevector which shifts my joints. So my shoulder joint (human rig) gets rotations from it.

I tried to solve the problem via different tutorials which didn't help.

My tutor said that I should move my controll object for the polevector to the ellbow_jnt, then create the polevector and move the controllobject where I need it.

But then I have a controllobject with translations...additionally rotated joints.

The next problem is the IK_FK of the left side of my charakter.

First to say. I have an IK/FK Charakter with a switch.

When the switch is on (IK ON) and I move the left arm slightly down or to the left side, the arm starts jumping and messing up the animation. When I move it further, then the rigs goes back to normal and I it moves like it is supposed to!

It seems to be a problem caused by the FK-controllobjects, which I orient-constrained to the joints (offset on).

I tried out to 0 the offset. which worked perfectly fine against the jumping arm, but when I turn IK OFF then my rig is messed up (Because the bones don't have an offset to the controllobjects anymore)

http://img3.myimg.de/Offset6813e.jpg

And I little question

Can I force visibility (on) for a child when its parent visibility is off? (I need to Parent the hand Controller to the FK. So when I use FK, that the objects move along)

I hope there is no missing information because I really need the help and will be glad if you guys can solve what I don't understand!

 Greetings Melo Chan!

[joojaa]

Can I force visibility (on) for a child when its parent visibility is off

No. But if you expand your horizon a bit youll notice that

a. every node that displays except joints is a shape
b. everything users think are nodes are not shapes
c. maya successfully hides shapes if you dont request maya to show them

So in effect you can accomplish teh same thing by hiding shapes instead.

for the other problems its impossible to say anything without seeing your rig.

[omkar-jere]

For the shoulder shift problem try this

Orient constraint the pole vector controler to the shoulder joint

then delete the oreint constraint from the pv control(don't freeze rotations)

now apply the pole vector.

[sorarey]

Hello!

Thank you for the answers.

I tried out to hide the shape thing. So can I use this in any way with Set-Driven-Key? (I want to hide the shapes with my switch to make clear what controllers you can use and what not) (I hope that the answer isn't Scripting...because I really have no clue about that in any way)

The Shifting Problem I tried out what you said...but somehow it didn't work I will explain what I did

1. Created controller at a good position + Freeze transformation

2. Orient Constrained the controller (Slave) to the shoulder joint (Master)

3. Then I deleted the Orient Constraint and applied the Pole Vector (DIDN'T FREEZE THE CONTROLLER)

=> It kept shifting

I don't know if I can upload the rig, because it's a group-project...it's not in my hands if I can do so or not. But I will ask the others what to do now.

Greetings

Melo Chan

[jbuck]

For the shifting: try the same technique but use the elbow instead of the shoulder. Don't freeze transformations -- use local translation to offset the pole vector control object behind the elbow.

You can use driven keys to switch wrist rotation control between IK/FK.  You'll need to offset your pole vector -- if it's too near it will cause "jumping" as you call it.

You can certainly use driven keys to control the visibility attribute. 

[sorarey]

Ok I fixed the problem with the jump of the arm while moving

I just used a parent constraint instead of an orient.

But now appeared another problem. When I parent the the handcontroller under the shouldercontroller on the RIGHT side everything is ok.

But when I do the same on the left (which now has a parent constraint instead of an orient) the hand starts flipping backwards. When I rotate it the controller gets a scaling somehow.

I want the handcontroller to move along with the FK but it should also be a part of the IK.

[sorarey]

@Josh Buck

I already have a switch for FK and IK which works.

To explain it better.

I want my FK-Controller to be Invisible when I use IK. That works with Set-Driven-Key on the Switch and the FK-Controllers. But the controller on the IK Should also move along with the FK. When I parent the Handcontroller (IK) under the FK-Controllers it will get invisible as well.

So I thought about getting 2 Handcontroller with two constraints and the Weights will switch as I switch from FK to IK. But with two constraints the rotation on the hand get worse.