Is procedural animation by poses based on Overgrowth possible on Unity?

Hi everyone,

I've seen on a gdc video from 2014 (http://www.gdcvault.com/play/1020583/Animation-Bootcamp-An-Indie-Approach) where a nice technique to animate characters (and other objects) is used by just using static poses, that will be interpolated to produce the animations.

The dev that talks about this has used this on Overgrowth, an early access title on Steam. I don't know what the game is made on, but it's not made on Unity, AFAIK. I've been trying to approach that with Unity, since it looked like a good idea.

In order to test this I thought I could animate a hand (e.g. that could be used in an FPS). I've generated AnimationClips with 3 poses (open hand, closed fist and pointing with index finger), so I can interpolate between them to get the animation of closing and opening the hand.

I've put those clips into an Animator and got them to interpolate linearly between them. It looks OK, but I need to control the interpolation, so I can get the nice interpolations that can be saw on the video (around 7:00 and 8:00).

In order to have better control, I set up a blend tree between the the open hand pose and the pointing pose and controlled the blending by code. This allows me to control the interpolation a bit, but still doesn't allow me to interpolate out of the [0, 1] range, as the blend tree seems to clamp it. I assuem that if I want to mimic what is shown on the GDC video at 8:00, I need to go out of the [0, 1].

I'm thinking that it may be that Unity is not exposing features for this to possible or nice to implement, since it seems like a non-standard approach to me. What do you guys think? Am I just overlooking the feature that will allow me to do that?