setFromNormalAndCoplanarPoint( normal, point ) {

		this.normal.copy( normal );
		this.constant = - point.dot( this.normal );

		return this;

	}
Sets the plane from the given normal and coplanar point (that is a point
that lies onto the plane).

@param {Vector3} normal - The normal.
@param {Vector3} point - A coplanar point.
@return {Plane} A reference to this plane.