setW( index, w ) {

		if ( this.normalized ) w = normalize( w, this.array );

		this.data.array[ index * this.data.stride + this.offset + 3 ] = w;

		return this;

	}
Sets the w component of the vector at the given index.

@param {number} index - The index into the buffer attribute.
@param {number} w - The value to set.
@return {InterleavedBufferAttribute} A reference to this instance.