unprojectOnObj( cursor, camera ) {

		const raycaster = this.getRaycaster();
		raycaster.near = camera.near;
		raycaster.far = camera.far;
		raycaster.setFromCamera( cursor, camera );

		const intersect = raycaster.intersectObjects( this.scene.children, true );

		for ( let i = 0; i < intersect.length; i ++ ) {

			if ( intersect[ i ].object.uuid != this._gizmos.uuid && intersect[ i ].face != null ) {

				return intersect[ i ].point.clone();

			}

		}

		return null;

	}
Unprojects the cursor on the 3D object surface.

@private
@param {Vector2} cursor - Cursor coordinates in NDC.
@param {Camera} camera - Virtual camera.
@returns {?Vector3} The point of intersection with the model, if exist, null otherwise.