1.6 The model
Quote: "General Model Theory" by Herbert Stachowiak, 1973:
"Models are always models of something, for someone; they perform their function for a time and serve a purpose."
Models must be created according to the rules defined in the modeling plan.
BIM information delivery manual (basics)
The more precisely modeling rules are applied, the smoother model-based collaboration becomes. Model merging problems can be circumvented thanks to defined rules, and efficient collaboration is made possible.
Relative positioning
Geometric modeling in the IFC data model is strongly oriented towards the use of a local coordinate system. So, for example, the placement of a column is not defined globally, but in relation to the coordinate system of the floor concerned. The floor coordinates (IfcBuildingStorey) are in turn modeled with respect to the building coordinate system (IfcBuilding). In turn, building coordinates are modeled with respect to the terrain coordinate system (IfcSite).
