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Rabbitpenny
07-04-2009, 06:05 AM
First, let me thank the forum for pushing me further with Lightwave than I ever thought I would go. Of course, give a kid a piece of candy and he'll want three. So...

I have 2 characters holding hands and swimming. I'd like their grasp to remain firm but their bodies to remain free to move. Such as rotating a bit at the wrist...that is, normal movements.

I thought I would fix all the hand, finger joints in IKB then carefully move the COG. I guess not. The whole model jumps, jitters and twists.

I'm not presuming IKB is the solution. Actually, since I thought it was the solution, it probably isn't. Any help is much appreciated.

RebelHill
07-04-2009, 08:50 AM
I thought I would fix all the hand, finger joints in IKB then carefully move the COG. I guess not. The whole model jumps, jitters and twists.

One of the reasons Im not a fan of IKB... its fine for a basic control setup, but has no real options for doing more advanced stuff like this...

You'll get the most predictable results from regular IK with goal objects, who's individual space you can manage, switch, and reparent easily...

check my character tuts in my sig.... download the 3 hour demo, and check out vid "6-Addl_Rigging"... it explains the step by step for properly matched IK repinning/parenting... Although it shows pinning bits of a character to other bits of itself, the technique would be just the same if those bits were being pinned to another, separate character.

Rabbitpenny
07-04-2009, 01:08 PM
Thanks for the reply Rebel...but WOW! My head's spinning like a model with unrested bones. Tell me that your pinning video will make sense to me if I purchase your complete tutorial. I feel Like a ten year old who stepped into the middle of Astro-Physics lecture. I like the results of your pinning video but honestly couldn't follow it. Does the complete series build sufficiently to help me understand the work flow?

RebelHill
07-04-2009, 01:48 PM
Thanks for the reply Rebel...but WOW! My head's spinning like a model with unrested bones. Tell me that your pinning video will make sense to me if I purchase your complete tutorial. I feel Like a ten year old who stepped into the middle of Astro-Physics lecture. I like the results of your pinning video but honestly couldn't follow it. Does the complete series build sufficiently to help me understand the work flow?

Lol... sorry bout that...

Yes the whole series builds itself from the groundup, starts slow, and gets faster and things start getting repetitive... that particular vid on the repinning is from quite far along in the set, so tis running fast as its just a "click this, now that" bunch of actions that we've performed a million times by that point...

You can also check out the controls, constraints, vid1... which explains the functions of the same as item system thats used in the repinning vid.

SplineGod
07-05-2009, 01:06 AM
If the whole model is jumping, twisting etc the most likely you dont have proper IK chains defined. If you want just the arm to move when using the wrist or elbow controll then you need to apply an IKStop to the shoulder. For the leg you can apply an IKStop to the hip and so on. The nice thing about IKB is that rather then forcing you to build complex uber rigs you can simply change your rig on the fly to make it adapt to different situations. Heres some free videos on various things you can do with IKB.
http://www.vfxcast.com/playlist/IKBoost/
Also IKB can be blended with standard rigs.

Rabbitpenny
07-05-2009, 06:29 AM
Thanks for responding SplineGod. Yes, I've seen your videos already. Your videos got me going with IKB.

Other than joint "fix", which is not working for me, I don't know how to use IKB to solve my problem. There's also RebelHill's repinning consideration-where, somehow, I'm going to repin the position of one character's hand to the hand of the other character. I'm considering this but am presently looking for a brain donor for me to be able to understand. (Interested?) Seriously, this, so far seems to be the only option. (Repinning, not brain transplant)

To reiterate, I achieve a pose...2 characters holding hands swimming (IK, FK) no problem. Now, while still holding hands, they move their respective bodies independently, just like you would envision two people doing.

I would appreciate any other help.

SplineGod
07-06-2009, 01:46 AM
You can mix LWs fulltime IK and IKB. For example the arms that need to stay joined can use LWs full time IK with goals.
IKB also can work with goals and Colin has a nice simple example of that on his site
at www.ikboost.com. Its the spear example.

Rabbitpenny
07-06-2009, 01:21 PM
Thanks, SplineGod. I knew if you and RebelHill would beat me with a 2 by 4, I would get it. The spear example is like your surf board example. It helped to be able to study the rig. "Good to go."...for now.

My problem was partially that I had so many fixed joints so far up the extremity chain that the model was not able to rotate around the restricted chain. (Atypical creatures).

I warned you I was not too bright. Thanks to both of you...a little smarter.

SplineGod
07-06-2009, 05:38 PM
Theres multiple ways to do things and provides a great deal more flexibility. :)