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 describe facilitate a specific use or workflow.

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.)
...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 MVD based Software Certification takes place. Software implementations are checked against the implementation agreements of an MVD.

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 example 1 (Reference View) cannot automatically support example 2 (Precast). Software tools need to update and extend their code to support multiple MVDs.

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

Coordination view (IFC 2x3 & Reference View (IFC 4.*)
Alignment based Reference View (IFC 4.3)
Design transfer View (IFC 2x3, IFC 4.*).

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

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