Whenever I change the rig animation type from generic to humanoid (it is a human character BTW) I get the following warnings:
Is this something to be concerned about? I had the model custom so I’m wondering if I need to go back to him with this problem. Big thanks in advance.
I’m having a similar issue. I’ve been troubleshooting and have narrowed down what the actual issues this causes are.
My biped in max hasn’t got anything unusual, it’s just stood there. I made some isolated movements such as centre of mass (COM) down (making him crouch), twist the COM with planted feet (so he turns at the waist), raise one leg and bend over by rotating the first spine link. But what I find is that when I export this and after I set up the avatar when it gets to the ‘bend over by rotating the first spine link’ not only does he bend over but BOTH LEGS come up, rotated with a speed and angle that matches the spine link. Somehow the spine is controlling the thighs???
I also get the muscleclip warning message about the spine and also the pelvis. I’ve done this before in previous versions (I’m on 4.3)and had no issues like this. I wasn’t aware that my pelvis and spine had any ‘translation’ animation… I tried swapping the avatar bone nodes around, swapped the pelvis for the actual root biped, swapped the spine links with each other and the hips and nothing seems to help.
This issue came to my attention by the way because I was trying to get a very simple sequence of tennis movements working and the characters legs ended up mirroring the movements made by the spine resulting in legs swerving all over the place 
I sent the warning messages to the modeler (something I should have done from the beginning). I’ll post his reply as soon as I get it (he seems very well versed in the subject so hopefully he knows what’s going on).
I guess it is an optimisation of humanoid animation - only animating the bones by rotation and not having to calculate the position and scale. Sounds reasonable…
I think it appeared with Unity 4.3 or 4.3.1, at least thats when I started getting those warnings. Funny thing is, the warnings are there even with Unity’s own example assets, you can try, download the Mecanim Example Scenes from the Asset Store. Now I get those warnings with all the 3ds Max Biped characters that I have, seems like suddenly (and very quietly) the industry’s biggest standard in biped rigs is not fully supported by Unity anymore. 
Please, Unity, let us know whats going on with this and how can we get rid of those annoying warnings?
I just found out why my legs come up when the spine moves. Sort of.
I had the tiny little ‘IK’ button in the preview window turned off 
I didn’t even know it was there, but I must have disabled it accidentally.
HOWEVER, I do still get that error and lots of unwanted motion in other situations.
for example, I have a forehand stroke tennis animation, the legs are static, the animation is isolated to the upper body in max for simplicity. However, in Unity when the spine twists to the right the pelvis sways to one side making the movement look very strange - like an exaggerated feminine hip-sway.
Sorry if this feels like I’m hijacking your thread, but I have a feeling our mutual error message is related…
Maybe it’s because in max the thighs are keeping in place with translation animation although their parent, the pelvis, is rotating. In Unity that translation on the thighs is lost as the warning says and they just rotate along with the pelvis, making a feminine hip-sway as you said.
I cant confirm that, but it would make sense.
Interesting, however in the hip-sway situation there is no animation on any bone lower than the first spine. The pelvis is held in place unrealistically (for testing purposes) and only the spine bone twists, but this still results in the pelvis moving which then results in the legs moving because they’re trying to stick to the floor with the feet, lol!
So with EVERYTHING immobile other than the first spine bone is there any logic that would make the hips move? Peculiar!
MikeErty, I had a similar problem (the one you say you solved with the foot IK button) that I opened a thread about here:
http://forum.unity3d.com/threads/219120-Body-Transform-Feet-Placement-IK
To solve it, I found that I had to open the Animator window, select the Each Take and then switch the “Foot IK” button on in the Animator’s Inspector Window. Then I had to close the Animator, select the animation .FBX in the Project window, Go to “Animations” in the Inspector, turn off “Anim.Compression” (or set the “Error” values just underneath to “0”), then scroll down in the inspector and check all the “bake” options to “on” and “original”. After I applied those settings, the feet seem to stay in place.
However, I AM still getting the error messages such as “Bip001Neck” has translation animation. It is not supported." Has anyone found out what causes this error and whether there’s a way to get rid of it?
The answer I got from the modeler I work with: “It looks like the errors you are getting on the Armature is due to some accidental Translation/Scale keys in the animations (It’s only supposed to use rotations), I’m getting rid of them and the IK bones for the next version of the rig”. On the next version of the model the warnings were gone. Hope this helps (I really have no clue).
Removing these translation and scale keys solved the problem? I’m having the same issue and I don’t have any translation/scale keys on my animations…
Bump!
I am still having this error, and actually, I have translation keys on my model, but thats what makes my character jumps a little when he is running:
How am I going to make something like this without translating its hips up a little?
