Research on spatial relation representation mainly includes spatial topological relation, spatial cardinal direction relation and spatial distance relation.
对空间关系表示的研究主要包括空间拓扑关系、空间方向关系、空间距离关系三大类空间关系表示的研究。
2
Until now, there is no general representation for 3d topological structure, especially topological relationships between 3d solid objects.