Parenting a IK hand bone to a gun

Question

Hey there guys I have a client who needs a hand holding a gun to move up and down the trajectory line of where a bullet would go. (ie the purple gun should be where the green gun is and it needs to slide up and down the pink bullet trajectory, keep in mind the character will be facing back to the camera)

How do I parent the IK hand to the gun so I can move the gun around with the hand and arm following? I’m using Human Generator V3.

Thanks in advance.trajectory.jpg

  • Omar Domenech replied

    I don't know much about rigging, but I do know a guy. I think he'll be able to help you. Let me ask around, maybe put up the Wayne Signal in the sky. @waylow

  • Wayne Dixon replied

    Hi Ross,
    I don't follow 100% with exactly what you are wanting to do, and I have no idea how your rig is set up but here are some ideas.

    -Does the hand need to be constrained to the gun?  Can the Gun be constrained to the hand?

    -you could add a child-of constraint on the hand (to the gun) which should work fine.  Except if there is already parenting on the hand (say to the Root bone) then if the parent moves you will get double transformations.  This is a solution but you need to be careful with how you animate the scene.  If the parent moves - you can't use this method.

    -Use a "copy transforms" constraint on the hand to the gun.  However, because you will probably need it to be offset you won't want to constrain directly to the gun. Add an empty, put this where you want the hand to be in relation to the gun, parent the empty to the gun, then constrain the hand to the empty.


    Hope these solutions work for you.

  • Ross Franks(rfranks) replied

    Hey Wayne. The purple gun will need to be in the same position as the green gun, then animated moving down the pink axis line, so the hand would need to follow. So yeah the hand needs to be constrained to the gun. And I've tried child-of constraint and copy transforms and both aren't working unfortunately.