Let's say I want to animate 2 characters, but I want one of the character's forearm to be "parented" to the other person's hand. So in other words, character A is pulling character B, and when I move charA's right hand, I want charB's left forearm (and the rest of the arm) to move along with it.

I'm assuming this is either done with IK chains or constraints.. But I'm not sure how to create an IK from scratch and the only constraints I know how to use seems to be for   props only. They don't really work that well with body parts.

So what's the best way to achieve this?

Ok, here's what I'm trying right now:

I created an invisible prop, constrained it to character A's hand, then I made character B's forearm "look at" the invisible cube. It almost works, but unfortunately the rest of the arm and body don't follow the forearm's movement.

I need to somehow apply an inverse kinematics from the cube to the arm/shoulder but I don't know how to do that. :/

Anyone?

Check out this thread over at RDNA. I think this is what you want. :)

http://www.runtimedna.com/forum/showthread.php?63831-Using-Constraint-Channels-in-Animation

Quote - Check out this thread over at RDNA. I think this is what you want. :)

http://www.runtimedna.com/forum/showthread.php?63831-Using-Constraint-Channels-in-Animation

Thanks, I just tried it  but it doesn't seem to work right on body parts (unless I'm missing something).

ex: the forearm will be constrained to an object or body part, but it won't pull the arm and shoulder along with it. :(

you should be able to parent the hands together , just remember which hand is thparent and which the child.

 

Quote - > Quote - Check out this thread over at RDNA. I think this is what you want. :)

http://www.runtimedna.com/forum/showthread.php?63831-Using-Constraint-Channels-in-Animation

Thanks, I just tried it  but it doesn't seem to work right on body parts (unless I'm missing something).

ex: the forearm will be constrained to an object or body part, but it won't pull the arm and shoulder along with it. :(

 

Acually it should work. Heres two more threads for you to check out. Sorry but I'm not doing animations but I know it's possible to do what you want.

http://www.runtimedna.com/forum/showthread.php?63222-Constraint-Channels-and-Constraint-Objects

 

http://www.runtimedna.com/forum/showthread.php?63483-Animated-multiple-constraints

The only parts of a figure that can be parented to something from within Poser, are the BODY, and the 'goal' actors of IK chains, and only when those chains are turned on. By default only the hands and feet are IK goals, so with the default IK chains you can parent a hand or foot to a forearm, but you can't parent a forearm to a hand or foot.

In order to parent forearm to a hand, you would need to make a new IK chain with the forearm as the IK chain's goal.

To make an IK chain, open the Hierarchy Editor, click on "IK Chains", click the "Create IK Chain" button, name the chain. Next, click on the actor that is to be the part of the chain furthest from the goal, then drag onto the new IK chain. Repeat the drag & drop for the other actors, with the goal actor being the last one dragged into the chain.

P.S.

"Constraint Objects" are not something I know about. Must be something new added in P9 I guess. So I don't know if you can get the effect you want by using Constraint Objects, but the IK method in my last post should solve the problem.

Thank you both!

I managed to make it work. Although the result isn't as smooth as I was hoping it to be but it's acceptable.  What I did was simply constrain hand to hand and turn on the  hand IK for the character that's being pulled. But leave the other character's IK off.

It works alright but unfortunately it looks like the IK isn't pulling the guy's shoulder/chest, just the hand-forearm-arm. And then it stops getting pulled when the arm reaches it's "maximum strech". But this is minor I guess since I could just manually move the torso around in a keyframe.

lesbently, I'll try your method later and see which one is best for what I'm trying to do.  Thanks for the tips. :)