animation blendMode: Additive vs Blend

Hi all,

What is the difference between AnimationBlendMode.Additive and AnimationBlendMode.Blend, for non animation/CG experts ?

ie, when should I use one or the other (for example, in facial animation where lip sync needs to be mixed with emotions, which act on the same Transforms - for example, mouth corners).

(the docs are a bit scarce on this topic)

Regards,

 

In a very basic sense, Additive mode will simply ADD to the existing transform that exists on a bone.

Using numbers for example...if a bone's x position is currently 5, and the additive animations bone x pos is 1, then it will add them together for a result of 6.

With Blend mode, it will blend all active animations together. So if you have two animations playing at 0.5 weight each, and one has a bone x pos of 2 and one has a bone x pos of 4...it will then blend between those values to a value of 3.

Does that make sense?

In most cases you will use AnimationBlendMode.Blend. An example usage of AnimationBlendMode.Additive would be for adjusting an aim pose. But it really comes down to your own use cases, and how you want to use it.

 

Yes, thank you.

So, in facial animation there's no use for AnimationBlendMode.Additive ? as in http://unity3d.com/support/documentation/Manual/Character-Animation.html#LayerExample it is written that "Additive Animations and Animation mixing ... are important for creating facial animations." (I understand, and use, animation mixing)

 

Honestly, I'm not sure if you'd want to use Additive or Blend mode for facial animation, as it's not something that I have personally had to work on. My guess though, is that for facial animation, that you'd most likely want to use Blend mode.

Their example uses of Additive mode at the link seems like great examples to go off of though.

 

They probably mean you should use additive for facial to avoid having your facial animation be interpreted as a full body animation. Simply specify which bone will be affected by the animation, set that anim to additive, and facial animations should be able to run on top of your other animations