The mysterious 'update' button.

After coming across numerous problems with Mecanim and setting up avatars, I came across an unusual 'fix'. Whilst this seemed to fix things from the onset, it caused major problems further down the pipeline and is something you should avoid.


Here, you can see the default settings of a .fbx animation file upon first loading it into Unity. Excellent, now we want to change the Animation type to 'humanoid' and avatar definition to 'copy from another model' (something which has already been set up previously).

Now, for whatever reason the order in which you click these buttons seemingly yields a different result. You'll notice that if you change the animation type to humanoid then click apply, then change the avatar definition, and then click apply once more, a little button labelled 'update' will appear.

How interesting, I wonder what happens if we change all the settings in one go without going through this two stage process of clicking 'apply' twice.

No update button... What!? Whether this is a bug or a feature, I have no idea. However, from an initial glance, it seemed as though leaving this button un-clicked fixed a lot of problems (intersecting parts of the rig with the mesh, additional bones/joints affecting the avatar etc).

BUT!!!

In the long run, it seems to leave the avatar in a weird limbo between 'generic' and 'humanoid' setups. For one, no root motion will be generated when this update button is still visible, your looping indicators will not change depending on the frame range, amongst many other problems.

For anyone with any further knowledge, please let me know what this feature is for. For anyone else, to save yourself from future pain, just click the button.