Blend Trees

[bhouston]

Unity & Unreal Engine use blend trees to blend between different clips in a realistic way. Details are here:

#6881 (comment)

#6881 (comment)

/ping @crobi

[donmccurdy]

Is this addressed by the new animation system, or is the request here for more of a state machine abstraction around AnimationActions?

[crobi]

AFAIK the issue was opened before there was the new animation system.

Blend trees are mostly for blending of related animations (e.g., running and walking), not transitions between unrelated ones (e.g., running into jumping).

In a blend tree, leaves are animation clips and inner nodes control the weight (and time warp) of their subtrees. An example inner node would be a crossfade, which assigns weights w and 1-w to its two subtrees.

From what I see, AnimationAction could be used to implement a blend tree, but it would require some work.

[bhouston]

Blend trees could be done via converting AnimationMixer from a single node into a tree of AnimationMixers I understand.

[looeee]

Presumably related: #18822

[jmschrack]

I've recreated Unity's blendtrees for anyone else finding this post in the future. https://www.npmjs.com/package/three-blendtree