update() {

		const geometry = this.geometry;
		const pointMap = this.pointMap;

		const w = 1, h = 1;

		// we need just camera projection matrix inverse
		// world matrix must be identity

		_camera.projectionMatrixInverse.copy( this.camera.projectionMatrixInverse );

		// Adjust z values based on coordinate system
		const nearZ = this.camera.coordinateSystem === WebGLCoordinateSystem ? -1 : 0;

		// center / target
		setPoint( 'c', pointMap, geometry, _camera, 0, 0, nearZ );
		setPoint( 't', pointMap, geometry, _camera, 0, 0, 1 );

		// near

		setPoint( 'n1', pointMap, geometry, _camera, -1, -1, nearZ );
		setPoint( 'n2', pointMap, geometry, _camera, w, -1, nearZ );
		setPoint( 'n3', pointMap, geometry, _camera, -1, h, nearZ );
		setPoint( 'n4', pointMap, geometry, _camera, w, h, nearZ );

		// far

		setPoint( 'f1', pointMap, geometry, _camera, -1, -1, 1 );
		setPoint( 'f2', pointMap, geometry, _camera, w, -1, 1 );
		setPoint( 'f3', pointMap, geometry, _camera, -1, h, 1 );
		setPoint( 'f4', pointMap, geometry, _camera, w, h, 1 );

		// up

		setPoint( 'u1', pointMap, geometry, _camera, w * 0.7, h * 1.1, nearZ );
		setPoint( 'u2', pointMap, geometry, _camera, -1 * 0.7, h * 1.1, nearZ );
		setPoint( 'u3', pointMap, geometry, _camera, 0, h * 2, nearZ );

		// cross

		setPoint( 'cf1', pointMap, geometry, _camera, -1, 0, 1 );
		setPoint( 'cf2', pointMap, geometry, _camera, w, 0, 1 );
		setPoint( 'cf3', pointMap, geometry, _camera, 0, -1, 1 );
		setPoint( 'cf4', pointMap, geometry, _camera, 0, h, 1 );

		setPoint( 'cn1', pointMap, geometry, _camera, -1, 0, nearZ );
		setPoint( 'cn2', pointMap, geometry, _camera, w, 0, nearZ );
		setPoint( 'cn3', pointMap, geometry, _camera, 0, -1, nearZ );
		setPoint( 'cn4', pointMap, geometry, _camera, 0, h, nearZ );

		geometry.getAttribute( 'position' ).needsUpdate = true;

	}
Updates the helper based on the projection matrix of the camera.