Model's Arms are Broken

I’ve a model again. It works for the most part, but the arms are flipped - they look like they’ve rotated 180 degrees.

The model’s skeleton is directly taken from a previous model.
Any help?

Well that’s going to be your exact issue right there. An animation tells each bone where it is and what rotation it has at each keyframe. You’re taking a different skeleton and trying to make it use the same animations which is most likely going to result in distortions or bones that have different orientations that are suddenly forced into a new alignment; it’s essentially taking bones and forcing them into the HL2 animations regardless of your model’s stature. You could compared the orientations of each bone to that of a Valve skeleton and fix it, but for best results you should just re-rig the model to the Valve skeleton.

Assuming you renamed the bones to the Valve_biped skeleton (judging from the animation), you might have placed the left arm bones on the right and vice versa.
Another possible source of error is the origin of the arm bones might have been rotated somehow.

The skeleton was taken from basically an identical model that I have already rigged for Source - it already had a Valve skelly.

The arms aren’t flip flopped, but I’ll play with rotation. Honestly, that’s probably it.

[editline]6th October 2014[/editline]

I flipped the arms but they’re still aiming backwards.
For any willing to help, if you want to look at the model itself, it is here.

I took a look at your model and found a fix for your problem.

Rename the “ValveBiped.Bip01_R_Clavicle” bone to “ValveBiped.Bip01_L_Clavicle” and vice-versa.

And there are some… pointless looking bones in there you might want to remove, like “Roxas_Hooded” and “ValveBiped.Bip01_R_Elbow.”
I would also recommend the removal of “ValveBiped.Bip01_Spine4” as I’ve never found much use for that bone myself.

The elbow is a helper bone which can easily be used by the model. Usage isn’t necessary, but it’d be a good chance to learn a little about helper bones. As for Spine4, that’s where the neck and clavicles link to the rest of the skeleton. You’d certainly run in to some complaints from the engine for missing such a bone suddenly. There’s really no reason to remove it and it’s still used for helping the spine curve with some extra smoothness.

Don’t mind my super late reply :x
I switched the clavicles but although the animations looked better - arms were positioned mostly correctly - it just doesn’t look natural like most models animate. The arms bend at funny angles and just look odd in general. Any ideas?

Can you show a photo of it? Also, you didn’t happen to edit the bones posisition did you? :o
Moving/editing valve skeleton bones will usually distort the model and it’s animations.

Honestly, you’d be better off just re-rigging the model. It’s never going to look as natural as you want it to when you’re forcing animations onto a foreign skeleton. Renaming them isn’t even much of a shortcut; you could’ve been done by now had you already started on just rigging it.

I’m probably just gonna re-rig it, yeah.
I dunno why you think I’m “forcing animations” though. I took the bones from an identical model that I’d already made for the Source Engine with a Valve Biped skeleton - it’s not a foreign skeleton.

My bad, I may be thinking of another thread. I’m not sure why using a skeleton taken from your own model is resulting in such awkward problems unless you’ve manipulated the bones at all.

If you’re using 3ds max and just want a very quick rig, you can use the skip wrap modifier and reference an existing rigged Source model. You’ll want to tweak the rig afterward but it’s still useful in some scenarios.