I Recently got a copy of the Toolkit through my work to prep for a motion builder switch over, i am a very proficient character rigger in maya but seem to have run in to a couple of walls when trying to implement the reverse foot using AUX pivots on to a “joystick control”

So far the class has been awesome but this one thing i seem to be stuck on.

I create 4 aux effectors for the ankle:

heel_Ctrl -> move to heel pivot
Ball_Ctrl -> move to location of the ball joint
Foot_Ctrl -> leave at ankle
Ankle_Ctrl -> leave at ankle

Then on on the Toe

Toe_Ctrl -> move to toe Pivot

After that i group them like this top to bottom

Foot_ctrl
heel_Ctrl
toe_Ctrl
ball_Ctrl
ankle_Ctrl

My reach settings are as so:

Foot_ctrl -> t=0 r=0
heel_Ctrl -> t=0 r=0
toe_Ctrl -> t=100 r=100
ball_Ctrl -> t=0 r=0
ankle_Ctrl -> t=100 r=100

The issue i am running in to is when i rotate the ball_Ctrl forward the toe the ball and toes joints get pushed down (see attached image)

Originally i thought that it was because my leg joints weren’t straight, but when i took the skeleton from the class and tried it on there it was doing the same thing. That leads me to beleive that i am missing a step somewhere that i cant seem to find in the docs for the class.

I also attached the 2009 motionbuilder file of the skeleton from the class.

	Attachment

	Attachment
17602_ghCd2B19Qt6VGPuDeNxK.zip

I can’t seem to extract your file.  It appears to be corrupt.

Kelly

MotionBuilder QA

hmm interesting… here is another copy of it, i included the .bck folder that gets created on save.

It is also a 2009 file, not sure if that is part of the issue or not.

	Attachment
17615_zoyVYOgm8OEkKnBfuk9r.zip

ok, that one works.  thanks.

Kelly

cool, thanks for taking a look at it.

I remember having the same issue when rigging in maya at one point and the problem was that the pivots werent in the correct spots for the IK handles.... though im pretty sure they are in the right spot here…

I will try and look at the file tonight..

I looked now..

the problem is you left the reach on for the ankle effector. so it is mixing 50% between two reaches.

Brad Clark
Co-Founder: Rigging Dojo-Teaching the art and science of character rigging
Author: Inspired 3D Advanced Rigging
The Character Animator Toolkit for Motionbuilder :available now:

Thanks Brad,

If i had a dollar for everytime it was something simple like that…

BTW your class notes are awesome, and your Deformations and Rigging book you guys put out a while back helped get me through most of my rigging classes back in school, and i still have that copy sitting on my desk for reference.

I look forward to seeing what you will come out with next.

Thanks for helping out

Adam

One other question,

with this external rig, it seems like the ik and fk skeletons have trouble utilizing it, if i try to zero out the foot_ctrl it goes to 000 in WS, yet if i zero the ankle effector nothing will happen… is there a way around this? It looks like it happens in the completed example rig to.

depends on how your zeroing it… if you have a parent object that is the zero pose it will zero to what ever is parent space. 

The FK skel should not have an issue but the foot rig ctrls really take over control just like on any reg. animation rig of the main IK effector for the leg.  While you can still use it as a target , its best to hide the main ankle ctrl and treat it just like an IK handle in maya.

Brad Clark
Co-Founder: Rigging Dojo-Teaching the art and science of character rigging
Author: Inspired 3D Advanced Rigging
The Character Animator Toolkit for Motionbuilder :available now:

Ah i see that makes sense, i was looking at the fk skeleton before i set a key on it.

I made a parent to zero from and that seems to work, though it does seem as though going to “stance pose” is no longer an option, just zeroing all.

This rig is great, after i make some fine tunings, i will present it to all my animators next week and see how they like it. The one thing i added was a “Pirouette Ctrl” on the foot, which is basically just a pivot on the ball (Like you are grinding out a cigarette).

Adam