Model View Definition (MVD)

Model View Definition (MVD) and BIM data exchange

Model View Definition (MVD): key aspects of the IFC views and their use in BIM data exchange

In this post I’ll explain what a Model View Definition (MVD) is and how it enables effective IFC information exchange.

I’ll also provide you an example file (that you can open with usBIM.viewer+) to verify in a practical manner the various concepts that we’ll examine further on this article.

MVD (Model View Definition)

MVDs are defined by buildingSMART International as IFC schema subsets to describe data exchange for a specific use or workflow.

These filtered IFC views basically allow you to simplify the data exchange process and to avoid sharing useless or redundant information while following standardized procedures.

The following image shows ​​the completeness of the IFC schema and how a specific MVD is able to streamline it according to the information useful for a specific scope.

MVD representation

Schematic representation of the MVD – [Source: Mark Baldwin, The BIM Manager, 2019]

Clearly, the MVD is a filtered view that allows users to export specific packages of the model information to meet a particular use.

Let’s imagine that we have an entire BIM model, that is a digital twin complete with schematic information. We can simulate this model through a federation of models.
The different MVDs applied to the federated model will allow us to obtain:

  • a structural model
  • an architectural model
  • a MEP model

The function of the MVD is to support the data exchange scenario and provide an optimal approach for software developer to implement IFC-based information.

Here is a list of the different MVDs that refer to different construction areas and to different IFC versions that you can check on the buildingSMART website:

IFC 2X3Coordination Viewpublished
IFC 2X3Space Boundary Addon Viewpublished
IFC 2X3Structural Analysis Viewpublished
IFC 4Reference Viewpublished
IFC 4Design Transfer Viewpublished
IFC 4Quantity Takeoff ViewNOT published
IFC 4Energy Analysis ViewNOT published
IFC 4Product Library ViewNOT published
IFC 4Construction Operations Building Information ExchangeNOT published

Model view definition and software certification

Another function of the MVD is its use for the certification of software that can control certain processes.

In fact, buildingSMART grants a certification when a software can correctly manage the set of classes present in the IFC schema and which are included in a specific MVD.

Here is the page with all the software certified by BSI.

certified software by buildingsmart

Certified software for the various MVDs

For each certified software on the BSI website, it is evident that the following aspects are showed:

  • schema version (ex: IFC 2×3)
  • MVD- exchange/requirement (ex. CV 2.0 arch)
  • Import/Export
  • data
  • report link, with all the specifications of the tests performed for the certification. These datasheets can also be downloaded.

Model view definition: the IFC example ready for download

Let’s now take a closer look at a practical example to better understand MVD and what are its functions in an IFC file.

First of all, download example file and open it with usBIM.viewer+ .

Model View Definition in usBIM.viewer+

usBIM.viewer+ interface

The file contains a federation of 3 models:

  • Architectural
  • Structural
  • Installation systems

You can view the different entities present in the IFC file with their properties. In this regard, just select the entity and read the relating values ​​in the properties toolbox (on the right-hand side).

In addition, you can also recreate selection groups and selection filters that will both allow you to recall the object selections any time, hence making the file management simple and streamlined.

The selection groups are set of objects that you can choose directly from the 3D view and that you can name.

For example, you can create selection groups for:

  • components installed on the same day;
  • supplies from the same company;
  • items that need maintenance;
  • etc.

The selection filters are object sets that are filtered according to certain characteristics they have in common, for example the kind of entity (eg. All the windows), geometry (dimensions), characteristics and properties, IFC file membership, etc.

In particular, it is necessary to specify :

  • entity
  • condition
  • IFC file

Try usBIM.viewer+  and create filters or groups in the file that you have downloaded.