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kmp3d
03-10-2003, 06:25 PM
I was wondering what is a good way to rig a wrist on a character. I've been just using IK for the arm and then point constraining the IK to a locater, and constrain the pole vector of the IK to another locator, then I orient constrain the wrist joint to the wrist locater. This works but I don't know if this is really the best way. The problem with the orient constrain is that the hand is always orient to the locator. So if I grab the locater and move it the hand always points out to the side unless of course I rotate the locater. I think more of what I want is to be able to move the arm and hand stays straight with the forarm, which I was able to acheive by zeroing the weight on the orient constrain, but thats a pain to change the weight of the orient everytime I want to rotate the wrist. I know theres a better way to do this, I've seen rigs that work this way. I'm just not sure of how to rig the wrist and arm so I can achieve this. Any ideas.......? :hmm:

colt
03-10-2003, 07:07 PM
Ever tried it this way?

http://www.thegnomonworkshop.com/tutorials/arm_ik_fk/arm_ik_fk.html

I don't know if it's perfect, but quite handy imho.

ntmonkey
03-10-2003, 07:24 PM
Would an almost completely rigged skeleton help you? The rig is quite complicated, moreso than any that I've seen online. Its a more realistic setup than something that you would whip together. If you want it, I could send it to you, or have you download the .mb file from a link and let you look at it.

Lu

kmp3d
03-10-2003, 07:38 PM
colt: I think I may have read through it before..... I'll take a closer look at it and see what I can get.

ntmonkey: If you want to you can send me the file at kmp3d@yahoo.com. I am trying to figure out rigging for myself. I wouldn't mind looking at it and seeing what I can learn from it. So far though I think my rigging has come out quite well and for me the way I rig is pretty easy to animate and has a wide range of motion and control. I'm just looking for ways to improve upon it. :thumbsup:

ntmonkey
03-10-2003, 08:39 PM
Kmp3d,

Here's the link to my webpage. There's tons of stuff in there so I hope you're not overwhelmed. The layers should allow you to turn off the poly bones in case the scene gets kinda messy. If you have any questions, email me below and I'll be glad to answer. Make sure you make the subject obvious if you do decide to email me.

Hope this helps,

Lu


www.visualeruptions.com/downloads/hopkinsbody.mb

kmp3d
03-10-2003, 08:54 PM
ntmonkey is your webpage messed up or something. I got the file but there isn't anything else on your main page...... or are you just in the process of construction?

ntmonkey
03-11-2003, 04:18 AM
Kmp3d,

Yeah, I apologize for the lack of content on my webpage. I haven't really any time to work on it. Plus, I'm in the process of learning Dreamweaver so I can make a decent webpage. Adobe GoLive just wasn't getting the results I needed. I hope you got the file okay, and again, if you have questions about the controls, just let me know. All those boxes, curves and arrows can be confusing.


Hope that helps,

Lu

dmeyer
03-11-2003, 05:30 PM
The gnomon DVDs on Kinematics will teach you tons about rigging. Recommended. :buttrock:

Carina
03-13-2003, 11:43 AM
I would just like to second dmeyer on this;)

ilasolomon
03-14-2003, 12:23 AM
Maya IK (4.5) has a TWIST attribute itself for the elbow, so you don't need an additional pole vector for the arm, but for the wrist twist, I use a very simple method:

you have an IK from arm_root to the wrist. hand palm faces down.

devide the forearm bone into 3 (2 more joints between ankle & wrist), now add an attribute to -for example- a spline curve & link this curve to wrist joint or link arm IK Handler to the curve (dpends on what you prefer to animate, IK Handle or the helper Curve)
limit this attribute from -5 to 10 (or whatever you want)
now connect this new attribute (name it forearm twist or roll) to the rotation of the 4 joints, using Driven key, from ankle to wrist
this way:
from 0 to 10 --> joint 1 (ankle) rotates 6 degree | joint 2: 12 degree | joint 3: 24 degree, wrist joint 48 degree (total: 90 degree) direction: FRONT
from 0 to -5 --> joint 1: 3 | joint 2: 6 | joint 3: 12 | joint 4: 24 (45 degree) direction: BACK

in animation MIX these rotations with default IK TWIST rotation to achieve a 180 degree twist for the entire arm.
but remember that you HAVE TO DISABLE ARM IK before animating the new forearm roll attribute.

I hope this is what you needed & helps you.

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