BlendTree

Explained in Animation.

class BlendTree

import { BlendTree } from '@driftengine/animation';

Constructor

`new`

constructor(root: BlendNode, jointCount: number, bind?: Pose | undefined)

Parameter	Type	Description
`root`	`BlendNode`
`jointCount`	`number`
`bind?`	`Pose \| undefined`	The bind pose, or omitted for one whose channels start at rest. Supply it whenever the clips are rotation-only, which is most of them. `sampleClip` leaves a channel no track mentions exactly as it found it, so a rotation-only clip preserves whatever translations the pose already held. `blendPoses` cannot do that — it interpolates every channel of two poses — so without a bind pose here the scratch poses start at zero translation and every joint collapses onto its parent's origin the moment a tree or a transition is involved. Found by building a demo scene with it: one figure folded in on itself and the other, which happened to go through `retargetPose` instead, did not.

Methods

`set`

set(parameter: string, value: number): void

Set a parameter, refusing a name no node declares.

Parameter	Type	Description
`parameter`	`string`
`value`	`number`

Loud rather than ignored. A typo silently does nothing, and what a consumer then sees is an animation that will not respond — a symptom a long way from the misspelling that caused it, and one no test of theirs would catch. What it costs is that a caller cannot set a parameter ahead of building the tree that uses it.

`evaluate`

evaluate(timeSec: number, out: Pose): void

Sample the whole tree at timeSec into out. Allocates nothing.

Parameter	Type	Description
`timeSec`	`number`
`out`	`Pose`

timeSec is the clock for every node that did not name one of its own, so a tree of ordinary clips behaves exactly as it did before clocks existed.