XR · class

HandSkeleton

One hand's joints, allocated once and written into every frame.

Explained in XR.

class HandSkeleton

import { HandSkeleton } from '@driftengine/xr';

In depth

Sixteen floats a joint because a joint carries a full transform: a fingertip has an orientation as well as a position, and a consumer drawing a mesh needs both.

Properties

Name	Type	Description
`matrices`readonly	`Float32Array<ArrayBuffer>`	Row-major transforms, `JOINT_COUNT * 16`, in world space.
`radii`readonly	`Float32Array<ArrayBuffer>`	Joint radii in metres, or 0 where the runtime offered none.
`tracked`readonly	`Uint8Array<ArrayBuffer>`	Whether each joint had a pose in the last frame that was read.
`trackedCount`	`number`	How many joints were tracked in that frame. Zero means the hand is not visible.

Accessors

Name	Type	Description
`visible`get	`boolean`	Whether anything at all was seen, which is what a consumer branches on before drawing.

Methods

`clear`

clear(): void

Forget everything, which is what a source going away means.

Separate from a frame where every joint is merely untracked: a hand that has left has no last known pose worth holding, and a consumer that fades on loss needs the two told apart.