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RC1 release summary

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Release Notes

The purpose of the IFC2x Edition 4 is to enhance the capability of the IFC specification in several areas of building elements, building service elements and structural elements and accompanying basic definitions. It also corrects several known technical problems found since the release of the IFC2x Edition 3 specification and to improve the documentation generally. Some elements that have been deprecated in earlier releases have been removed or adjusted.

A "What's new in IFC2x4 RC1" section is added to the specification for a quick overview of major changes, the "IFC2x3 TC1 to IFC2x4 RC1 change log" should be consulted for more details. Please also look into the "IFC2x3 TC1 to IFC2x4 list of deprecated elements". For a basic introduction to IFC2x4 see the unveiling of IFC2x4 summary presentation.

In addition to improvements for the IFC data schema itself, IFC2x4 should also improve its readability. Among the new features introduced in IFC2x4 RC1 are:

  • inheritance listing
  • listing of all IFC object occurrence and type pairs including the predefined types (i.e. the built-in "catalog", or object taxonomy)
  • listing of all all IFC objects with applicable property sets
  • multi-lingual property sets (currently English, German, French, and Japanese), more languages should be added soon.


Purpose of the Release Candidate

The Release Candidate 1 focused entirely on the consistency and stability improvement for IFC2x4. The list of deprecated entities had been discussed with all interested parties and a decision had been made to remove some obsolete definitions. A major effort had been undertaken to make basic functionality of the IFC data schema consistent throughout the schema. The IFC object occurrence and type tree has been completed and harmonized, material assignment unified and external classification made more stringent.

Another main feature of IFC2x4 is the provision of multi-lingual property definitions to make the localization of IFC based content easier. The IFC2x4 RC1 now contains French, German and Japanese definitions for IFC property sets, available as XML configuration files to be processed automatically. More translations, including e.g. Korean, are under way.

The purpose of publishing the IFC2x4 RC1 is to further encourage the international buildingSMART community to provide feedback and issue reports in order to increase quality and implementability of the next IFC release. The focus of the feedback should be to fix still existing bugs and inconsistencies between the various parts of the IFC schema and to improve documentation and to drive out ambiguity in definitions. However no major schema changes are acceptable for the upcoming release candidates. Any comments about the ease of use and examples to demonstrate the use of IFC concepts that could be incorporated are highly appreciated.

Invitation for review

We invite all interested parties to review and comment on the IFC2x4 RC1. See "how to use the issue database" on details for registration and usage of the issue database, if you are registered already go directly to the IFC Review Issue Database. The IFC2x4 RC1 review process has started on 25. May 2010 and is expected to close on 02. Juli 2010.

The next release candidate 2, IFC2x4 RC2, will focus predominately on improving the readability of the specification and to further improve the documentation part. All interested parties are invited to suggest new ways of providing an introduction into the IFC2x4 specification (as a primer, an overview implementation guide, or similar). Please contribute to the improvement of IFC as the international openBIM specification.