Date Added: Mar 2010
In GIS and spatial databases, cardinal directions are frequently used as selection and join criteria in query languages. However, most cardinal direction models are only able to handle two-dimensional spatial objects. But, e.g., geoscientists and engineers in fields like geography, cartography, soil engineering, and landscape modeling have shown an increasing demand for modeling cardinal directions between objects in the three-dimensional space. Unfortunately, the few available 3D cardinal direction models suffer from several problems like the coarse approximation of the two operand 3D objects in terms of single points and minimum bounding boxes, the lacking property of converseness of the cardinal direction relations computed, and the incomplete coverage of all possible direction relations.