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adamredwoods
08-22-2008, 12:37 AM
My ideal version of an "up vector" is shown in this attached scene.

It pops too much for it to be truly useful, but it is an example until I can find something more stable.

What is an "up vector"? It is a controller that tells an object which way is up. In this case, I've attached an extra bone to point to which way is up. You can also think of it as rotating the "target" function by 90 degrees in the pitch axis, but controls the bank.

Where is this useful? It would be a nice controller for say, a neck, in a character rig. It can turn the head not just left and right, but up and down as well.

DeepThroat
08-22-2008, 12:44 AM
Try this.

Forget about XY Plane through Goal option.

Target Item+Pole Item work great!

adamredwoods
08-23-2008, 12:39 PM
Hm. If I replace the YZGoal with PoleVector, then it doesn't work.
Pole Vector doesn't work correctly on anything other than the BANK channel, whereas YZGoal does.

Note-- in that scene I am using Pitch YZGoal on a circular NULL to give my correct pitch to the parent bone (Pitch - Same as Item controller).

I suspect the "Up vector" example breaks because of a little gimbal lock.


If you can elaborate on your usage of the Target+Pole Item to use as an up vector, I'd be interested to see it.

adamredwoods
08-23-2008, 12:42 PM
EDIT: oops, i took off the WORLD checkbox on the Same as Item controller and now the breakage is gone.

dballesg
08-30-2008, 06:16 AM
Hm. If I replace the YZGoal with PoleVector, then it doesn't work.
Pole Vector doesn't work correctly on anything other than the BANK channel, whereas YZGoal does.

Note-- in that scene I am using Pitch YZGoal on a circular NULL to give my correct pitch to the parent bone (Pitch - Same as Item controller).

I suspect the "Up vector" example breaks because of a little gimbal lock.

If you can elaborate on your usage of the Target+Pole Item to use as an up vector, I'd be interested to see it.

Hi Adam,

For what I understand, the Pole vector can be used for the Knees of a Character, and the YZ Goal for the elbows???

Still trying to get my head around the Pole vector to setup correctly on my Draw Chain Tool script.

David

adamredwoods
08-30-2008, 04:35 PM
Pole vector and YZGoal *seemingly* do the same thing, but in advanced rigs I've found they react quite differently. in the above example, I encourage everyone to try switching the YZGoal for a Pole Vector and see what happens to the responsiveness.

ercaxus
08-30-2008, 07:17 PM
If you can elaborate on your usage of the Target+Pole Item to use as an up vector, I'd be interested to see it.

Look at the attachment. Isn't this how it's supposed to be used?

dballesg
08-31-2008, 03:26 AM
Look at the attachment. Isn't this how it's supposed to be used?

Hi ercaxus,

Yes it is how supossed to work.

Have you done that with the Make Joint Chain script?

That script ALWAYS add an extra joint were it applies the Pole Item to it, and Target the same joint to the IK Goal.

I suppose that is to make the Pole Vector more controllable.

Curiously I've been trying to see if the Pole Vector was suitable to control the elbow, and I wasn't able to make it work, and when I tried to create a scne that will show it, it works! :) Duh! :)

I attached it, and left the original chains BEFORE I applied the Make Joint Chain.

David

adamredwoods
08-31-2008, 03:39 PM
Look at the attachment. Isn't this how it's supposed to be used?

Yes, that is *THE* way to do it.

I kept forgetting that the POLE should be aligned a certain way, and the way to do that is to use a target to define your plane.

And it is best practice to place a separate joint to handle the chain.

A piece of thought:
I wonder if YZGoal would be better to be implemented as this TARGET+POLE. inother words: since YZGoal could be part of of an IK Chain, it could hook up the the IK goal. And the YZgoal would be separate.

Otherwise, I don't know what the advantages/disadvantages are to pole vs yzgoal.