I have spent the last few hours trying to get a look at type constraint setup for an upper body and can’t seem to figure it out. I also tried parenting aux wrist effectors to my “control” cube but that doesn’t give me the desired results when I move my cube around.

What I am trying to achieve is I have a character holding a rifle and is in a shooting posture, with it up on his shoulder and looking down the sights. I want to control how he aims that weapon, and his upper body movement derived from that, by animating a cube about 10 meters in front of him. I have a simple Aim constraint setup for his head to another cube and it works great, but for some reason I can’t seem to get a nice IK setup for the upper body that does the same.

I’m thinking there is a way to do this but am obviously missing something.

Thanks for any suggestions.

-John

You would have to control the upper chest rotation along with the arms for this to work.

Pick up a cardboard tube or gun like thing and aim it and try out the motion your self.. see what part of you is actualy moving , you will find its not your arms, the movement comes from the torso.

Brad Clark
Co-Founder: Rigging Dojo-Teaching the art and science of character rigging
Author: Inspired 3D Advanced Rigging
The Character Animator Toolkit for Motionbuilder :available now:

there are a few ways to get this to work of course you could build an AUX ctrl rig for the upper body that is parented like the FK rig, you constraint that and then you can mix between the two systems depending on how complex you wanted or needed to get. have the aim constraints with weighted values or a mix of reach settings to help keep the anim alive but still aim the gun.

What did you send up doing?

Brad Clark
Co-Founder: Rigging Dojo-Teaching the art and science of character rigging
Author: Inspired 3D Advanced Rigging
The Character Animator Toolkit for Motionbuilder :available now:

I may try that later since it seems like it would give me a lot more control. But what I did now was something simple… I have left hand (holding front grip of weapon) parented to the right hand (trigger hand of weapon) and then I place the left hand where I want it. Then, on a new animation layer I can move the hands and the upper body follows fairly well.

The main limitation of this is the limited range of motion I can get out of it before the IK breaks down. But for the small movement changes I need at moment it works.