makeScale( x, y, z ) {

		this.set(

			x, 0, 0, 0,
			0, y, 0, 0,
			0, 0, z, 0,
			0, 0, 0, 1

		);

		return this;

	}
Sets this matrix as a scale transformation.

@param {number} x - The amount to scale in the X axis.
@param {number} y - The amount to scale in the Y axis.
@param {number} z - The amount to scale in the Z axis.
@return {Matrix4} A reference to this matrix.