setFromMatrix3( m ) {

		const me = m.elements;

		this.set(

			me[ 0 ], me[ 3 ], me[ 6 ], 0,
			me[ 1 ], me[ 4 ], me[ 7 ], 0,
			me[ 2 ], me[ 5 ], me[ 8 ], 0,
			0, 0, 0, 1

		);

		return this;

	}
Set the upper 3x3 elements of this matrix to the values of given 3x3 matrix.

@param {Matrix3} m - The 3x3 matrix.
@return {Matrix4} A reference to this matrix.