A REFERENTIAL SCHEME FOR MODELING AND IDENTIFYING SPATIAL ATTRIBUTES OF ENTITIES IN CONSTRUCTED FACILITIES

This paper presents a referential scheme for representing and identify ing the spatial extent of physical entities of constructed facilities, such as buildings and offshore structures. Using the basic operations of a non-manifold geometric modeler, a set of high-level algebraic op erations is defined. The scheme and its algebra are used for modeling the spatial attributes of a facility entity at two levels: primary and secondary. The primary representation uniquely captures an entity's s patial attributes at the ''skeletal'' level and is used mainly for ide ntifying discipline-independent topological relationships of that enti ty with others. Secondary representations, on the other hand, are used to provide an entity's discipline-specific geometric attributes. The topological relationships and geometric attributes of facility entitie s thus need not be explicitly stored, but can be computed on demand by the underlying non-manifold modeler.