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I want to parent a mag to the left Hand Thumb but once I target my Armature the mag absolutely changes LOCATION / ROTATION / SCALE this is really weird, I mean even setting it inverse doesn't help. I need assisstence. I tried doing this over a dozen times, but I just can't get it right.

My Blend file below:

Or maybe there is a better way to do it, easier without the Constraint ? basicly what I want is to animate the parent of the Mag to the thumb bone.

Thats what I see once the Constraint is applied:

enter image description here

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    $\begingroup$ By uploading it the BE you a agree to the Terms of Service, which lets us distribute it however we wan't, including commercially. Please request removal if this is a problem. $\endgroup$ – GiantCowFilms Sep 12 '15 at 19:15
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The Mag is moving/rotating relative to the gun (since it's parented to the gun). PLUS the Child Constraint adds it's Position/Rotation also to it. This causes the mess I guess.

How I fixed it:

  • Set influence of the Child of-Constraint to 0
  • Go to the last but one keyframe (99, where the mag is inside the gun correctly)
  • Delete all the keyframes for the mag
  • Now the mag should be inside the gun the whole time when the animation plays.
  • Keyframe the influence at frame 0 and the frame before pulling out the mag to 0. Also set keyframes for the mag /LocRot at the same key-positions.
  • Add another keyframe, where the hand will pull out the mag and set the influence of the constraint to 100. You will notice that the Mag is going to change it's position, now position it correctly for this keyframe.
  • Done, for the rest of the animation, the Mag is following the thumb.

Maybe you check out this "tutorial": https://www.youtube.com/watch?v=3Jx5X3fG4bY ... not professional, but seems to work (somewhere in the middle he has the same problem).

Here's the blend file:

Problem is, if you move the gun, while pulling out the mag, the mag itself will get an offset and will "drift" away...

Hope this helped a bit

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The problem is double parent transformations:

  • first from parent
  • second from child_of_constraint

The solution and how to cleanly set this up is:

  • do not give the Mag any parent, all parenting will be done with constraints
  • position the Mag so it is both in the gun and in the hand
  • set 1st child_of_constraint to the gun and Set inverse
  • set 2nd child_of_constraint to the thumb and Set inverse
  • switch parenting with key-framing both constraint influences, gun_parent will go from 1 to 0 and hand_parent vice-versa.
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