View Full Version : Good Hands

06 June 2007, 03:02 PM
I'm trying to figure out the best way to rig a hand.

I'm using Lightwave and was thinking about using a set of endomorphs or joint morphs.

Anybody know any good tutorials or have any theories on hand animation and modeling.

06 June 2007, 06:21 PM
Hey man, I worked on the rig/animation for the Cingular Blackjack commericals, and did the entire rig for the Cingular Flipbook commericals:

2 key elements about close up hands are:

1. Metacarples: these are the bones that run form the knunkle to the wrist.
You'll need to have them in the skeleton. They allow for the natural bends in poses such as spreads and fists. An example of this would be: take your right thumb and press your left pinkie knuckle upwards. You'll see that you can lift your pinkies base almost above the other knuckles.

2. Volume Pads: these allow the animator to shift the fatty mass around on the hand to show impact and pressure. Putting a joint at 'pad' of each finger tip will allow it to show compression. You should also put on at the base of each finger (so when the fingers bend ninty degrees) so the animator can pull that mass out, instead of having it interesct. Also, i put in an additional free floating joint to help with the mass in the triangle from the thumb to the index fingers. Came in handy a few times.

Out side of those, you'll probably want all kinds of blend options for each finger, such as:
-Faux FK
-IK Pole Pinning (does the pole move with the knuckle or finger tip)
-World Local Pinning (does the finger move with the wrist or stay global as if pressed on a table)

In the end, hands are complex with a lot of controls and options, some may never get used, but itll save you in the one shot that it is needed.

Good luck.

06 June 2007, 05:18 PM
Thanks Kiel. Don't think I can get as detailed on this model (mesh isn't that great) need to work on my flow control. I decided I would get decent deformations and then create a set of morphs

I gotta tell ya, i was surprised when i first found out that the commercial was an animation. I thought they may have used some paint, oils and lighting to get the look of it, and hired a magician to do the hand tricks. Best hand animation I've seen, O and best rig also.

Thanks again

06 June 2007, 09:27 PM
Hi Kiel,
You mentioned in your post about faux/false Fk, could you explain more about what that is,
really liked the commercials btw.


06 June 2007, 03:48 AM
Hey man, heres what I mean with Faux FK.

The basic setup was your standard 3 joint chain bind, 3 joint chain FK and a 3 joint IK (with a pole) working like a typical leg or arm, where the last knuckle was like the ankle.

However, since the other animators and I wanted finite control of the arc and flow (while in IK) without having to constantly blend in and out of FK, I gave them seperate controls over the knuckles.

The controls where zeroed out and the node above them was orient constrained to the IK joints. Then during the arc of the fingers I could just rotate the middle knunkle control and get the slight amount of overlap needed. This would also work with the other knuckles, but I found the middle one being used the most.

To maintain the ability to blend to pure FK, I orient constrained the bind joints to the FK joints and then the Fauk FK controls. This differs from the standard setup in which you would constrain to the FK joints then the IK joints.

In retro spec, this system (along with the others mentioned) where not only helpful, but necessary. The downside however was:
-increased setup time
-deeper complexity = greater chance of error
-slower scene computations (from all the constraints and additions)
-many more control shapes and systems for the animator to be aware of.

I have yet to find it necessary for this sort of hand setup on typical projects, however, I often will setup a single faux FK override for the knees and elbows of my characters to allow them to smooth the arc on an IK swing or break the joint if they wish.

Hopefully this is helpful for you.

Good luck

06 June 2007, 07:26 PM
Thanks for that, i think I know what you mean. Its given me some ideas,thanks again.


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