Hello,

I've done an animation basicaly a child anim, where he is walking backwards and then get pushed away in the air as if he was hitted.

The problem is that i realised in the animation that the problem came of the root_rot joint: there are some part of the animation when we see the whole sim to rotate like crazy and fast.

Please can you please tell me how I should fix this?
I thank you guys! <3

I think you don't have the choice, you need to fix it in SimPE itself. It's the same problem as the rotating tighs i think... I had it too but never figured out how to fix it though... You can always try to remove the negative values from the root_rot joint and/or adjust manually the rotation angle in SimPE...

That's a fairly common problem (see the section "When my object is turning in a circle, it suddenly spins around in the opposite direction for no reason!" from this thread: http://modthesims.info/showthread.php?t=239168 for a proper description of what's happening and why.)

The way I normally fix it is to manually edit the file, either in SimPE (which is slow, but familiar) or as a text file (which is faster, but more likely to fail spectacularly). Either way, if it's happening at a key point in your animation you haven't really got much of an option but to manually fix it in the anim file - Milkshape can't do it.