setup( builder ) {

		if ( this.needsPreviousBoneMatrices( builder ) ) {

			positionPrevious.assign( this.getPreviousSkinnedPosition( builder ) );

		}

		const skinPosition = this.getSkinnedPosition();

		if ( this.toPositionNode ) this.toPositionNode.assign( skinPosition );

		//

		if ( builder.hasGeometryAttribute( 'normal' ) ) {

			const skinNormal = this.getSkinnedNormal();

			normalLocal.assign( skinNormal );

			if ( builder.hasGeometryAttribute( 'tangent' ) ) {

				tangentLocal.assign( skinNormal );

			}

		}

		return skinPosition;

	}
Setups the skinning node by assigning the transformed vertex data to predefined node variables.

@param {NodeBuilder} builder - The current node builder.
@return {Node<vec3>} The transformed vertex position.