Counter Animations Not Applied After Locking Object to Unconstrained Rigged Bone

[Cannon Fodder]

I think this might be a bug, but I wanted to ask the forum before submitting a bug report just to make sure I'm not missing something obvious.

I locked an object to the hand of a humanoid model and SFM didn't apply counter animations to it. Now all the movement it did before being locked happens relative to the hand. Then I found out that if I locked the object to any other part of the body besides the arms, SFM applies counter animations like it should. They just don't get applied if I lock the object to any bones in the arms.

The model has a rig_biped_simple rig applied to it, but I removed the constraints in the arms by following this tutorial because I only wanted IK support for the legs. I believe that this has something to do with why the counter animations weren't applied because when I tried locking to the arm after reapplying the constraints, SFM applied the counter animations correctly.

Was there something else I needed to do to the arms, or is this a bug?

[Marco Skoll]

Community tutorials from 2012, particularly those relating to "tricks" or "something I've figured out", should always be taken with a massive pinch of salt, because this is only shortly after SFM was originally released - sometimes features have changed in the meantime, sometimes it wasn't a very good method in the first place.
(The Valve tutorials are however still pretty damn solid).

Because the constraints still exist, even if they're turned down, this affects the parenting of those bones, so I'm not at all surprised that you'll get weird results like this.

I'd recommend either using a rig like this (which includes partial FK support):
https://steamcommunity.com/sharedfiles/filedetails/?id=661850284

... or coding a rig that has full FK arms:
https://developer.valvesoftware.com/wiki/SFM/Making_custom_rigs

You can't really toggle a rig between one and the other in the way that video suggests without getting some issues.

[Cannon Fodder]

Using a rig without IK arms seems to have worked. I just removed any mention of the arm bones in a copy of the rig_biped_simple file to make an fk-armed rig and the problem went away.

When I first removed the original rig, however, all the animations in the arms were removed and the arms stopped moving completely. So in order to remove the rig without losing a month of work, I selected all the arm bones, selected all the time in the clip, and copied the animation in the motion editor. Then, I removed the rig and pasted the animation back on the arms afterward. The animation seems to have been restored.

So if anyone else reading this finds that they can't remove rigs without losing animations in unconstrained bones, just copy the animation, remove the rig, and then paste the animation back.