Model View Definition (MVD) - An Introduction

What is an MVD?

In general, a MVD, or "Model View Definition", is a specific implementation level of IFC to facilitate a specific use of IFC.

The IFC schema is designed to accommodate many different configurations. For example, a wall can be represented:

  • as a line (or curve) segment between two points;
  • as one of many types of 3D geometry for visualization and analysis (such as extruded solids or triangulated surfaces);
  • as simple forms or with specific construction detail (capturing individual studs, pipe fittings, wiring, etc.);
  • a certain configuration of spatial decomposition;
  • ...along with data such as engineering properties, responsible party, scheduling, and cost information.

Because an MVD is being implemented by Software Vendors, MVDs are the base against which the Use Case-based IFC Software Certification takes place.

MVDs Today

For a long time, everyone could create their own MVD and approach software vendors to implement it. This created a situation with several MVDs that have been created are not interoperable with each other, and need additional efforts for implementation in Software tools.

Software that supports Reference View cannot automatically support the Precast MVD. There are also examples where MVDs deviate from the ISO publication of IFC. Reference View for example adds new concepts and values to IFC that are not in the official IFC 4 publication.

This is why the concept of MVDs got much more restricted to guarantee interoperability.

There are three (base) MVDs which are the base levels of software implementation for IFC:

  • Coordination view (IFC 2x3)
  • Reference View (IFC 4 and IFC 4.3)
  • Alignment View (IFC 4.3)

Exchange requirements can be defined on top of these (base) MVD. This will increase the interoperability between different domains.

On top of these MVDs there are use cases defined for Architectural, Structural, MEP, Infra and Rail use of the MVDs. Software tools can get certified against these use cases. For more info contact technical@buildingsmart.org.

Defining exchange requirements

There are many different ways to define computer interpretable exchange requirements. BuildingSMART recommends to use the IDS standard. The buildingSMART IDS standard works hand in hand with IFC and bSDD to be able to define computer interpretable exchange requirements per use-case.