where sheet_position is a position on the Sheet. This position (which must be within the VIEW rectangle) may be specified by cursor. This command returns the back-projection of this position at Z=0 into the 3D world coordinate system of the current or specified VIEW, for example:
where position may be a 3D point or p-point, explicit p-point reference, origin of a named element, or an explicit 3D coordinate. This position or item may be specified by cursor.