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Question & Answer

Questions and answers about the improved coordination view documentation

 

 

Question:  why there are three columns for export, but only one column for import?

 

Answer:
The basic principle is to have 3 exchange requirements for exporting coordination view information, that is tailored to the main disciplines participating in coordination: Architecture, MEP (Mechanical, Electrical, and Plumbing) and Structural modeling. It takes into account that the subset of information is different based on each discipline. We still define one view for both export and import of the coordination view, but it shall satisfy, as a superset, the three exchange requirements. The coordination view is identified in the header (e.g.  FILE_DESCRIPTION(('ViewDefinition [CoordinationView_2.0]'),'2;1'); In addition, the exchange requirements met by this IFC data file may be added into the header, and it could include more then one exchange requirement .

[note: by now 2010-02-12 the exact syntax is only a proposal]

 

 

Question: what is the meaning of the color coding in the documentation?

 

Answer:
Three colors are used int the "EntityList" document: Green, Red, and Gray. The number 1 and 0 are just necessary to do set the color of the table cell automatically and to count the entities (1 means Green --> Entity is included in the Coordination (Sub)view); 0 means red --> Entity is excluded from the Coordination (Sub)view; Grey --> Entity is an abstract entity (x means included, empty cell means excluded in/from the Coordination (Sub)view)

 

 

Question: what does disallowed mean:

- The export of the entity is (will be?) not supported by the CAD application? or
- the export of the entity shall not be checked and tested within the scope of the certification? or
- the export of the entity shall be disallowed, forbidden for a certified CAD application?

Answer:
- the export of the entity shall be disallowed,
  i.e. it is forbidden for the certified CAD application to include it in the export, when exporting the "CoordinationView ONLY" (see explanations below for ONLY)

 

 

Question: what does required means on export - does a certified application have to support ALL entities?


Answer:
The export of the entity shall be supported by the certified CAD application exporting the "CoordinationView ONLY". If it is not supported, e.g. as it is out of scope for the application itself (and not only for the IFC interface), then this limitation has to be stated in the certification protocol published at the application center of the certification database (see below for "certification statement")

 

 

Question: what does required means on import - does a certified application have to support ALL entities?

 

Answer:
The user should assume that each coordination view file (independent of its export subview) is fully supported on import. This means the reading application should scan and parse all entities and let the user know which entity it has imported correctly and can be used in the application, but also which entities it cannot handle (e.g. because it is out of scope of the processed supported by the application). For example if the application cannot handle windows, as in the case of a structural modeling application, it is totally correct under the certification requirements, if it parses the windows and gives the message to the user that it has ignored a certain number of windows during import. It is not correct if it imports the file and silently ignores all the windows without any message to the user.

The limitation has to be stated in the certification protocol published at the application center of the certification database (see below for "certification statement"). Providing a proper import log is part of the certification criteria.

 

 

Question: how should a combined coordination view file be exported?

- i.e. an coordination view export file that contains both the architectural and the MEP part of a building information model?
- or, is it possible to combine them into a single view?

Answer:
It is supported by declaring the content correctly in the IFC header section, by FILE_DESCRIPTION(('ViewDefinition [CoordinationView_V2.0]', ...),'2;1'); and adding the two or more exchange requirements, that are met. Therefor it is possible to write a valid coordination view file, containing several disciplines.

 


---- explanations ------

"CoordinationView ONLY" means:

  • every application shall be able to export the CoordinationView only (i.e. without the addon views, like QuantityTakeOffAddonView, or SpaceBoundaryAddOnView),  i.e. to generate an IFC file with FILE_DESCRIPTION(('ViewDefinition [CoordinationView_V2.0]', ...),'2;1');
  • the expression [CoordinationView_V2.0] identifies the Model View Definition against which this IFC file is written, see IFC header implementation guide for more information about identifying the model view definition


"certification statement" means:

  • as part of the new certification procedure a support statement is required, including the listing of all elements supported, here the exceptions are to be listed (of cause exceptions -i.e. entities not supported- have to be within reasons and reflecting the nature and user experience of the application)
  • the listing and reporting of all elements supported is handled by the application center, see http://gtds.iabi.eu