Note on using root, rigging and exporting character to Unity...

Been having some troubles with Unity 3 for the past few days, primarily on the animation part. For some reason, every single animation which I exported into Unity 3 or 2.6, it kept pushing my character to Vector3.zero and stay stationary all the time in Play mode. Ultimately I figured out where the problems are, it's the ROOT's fault...

Well, for every character which I animated, I place a Point (in 3ds Max, which I named as "ROOT") at the origin while attaching the main bone to the Point, so that I can move the entire sets of bones without selecting all of them, actually it can also be done without using Point at all, it's just a habit of mine. So, my character consist of a gear-shaped mesh and a sphere ball, which doesn't exactly need any skinning or enveloping other than just attaching it to the bone I wanted it to move with...

Soon after animating it, I exported it directly into Unity and the problems I mentioned above starts occurring... 

It turns out that it couldn't detect the Point (ROOT) and I'll have to apply a Skin modifier to the gear-shaped mesh and add the corresponding bone into it. I exported the new version into Unity and the problem is solved... what a mess!