Applies To :	ISM Revit Plug-in
	Version(s):	N/A
	Environment:	N/A
	Area:	Import/Export
	Subarea:	Mapping
	Original Author:	Steve Crabtree Bentley Technical Support Group

Structural column and framing element section shape property definitions in Revit^® and ISM domains have major differences that prevent automatic data conversion.

Therefore, mapping files are required to specify how the data is to be handled when using ISM Repositories with Revit files.

The mappings functionality in the ISM plug-in for Revit is designed to provide powerful and flexible means to define mapping rules between section shape properties definitions in these domains.

In Revit, section shape properties are defined using a Family Symbol, which uniquely identifies both the fully qualified path of the Family File and the Family Symbol name.

ISM structural section properties can be defined by one of the following ISM section types:

Parametric Section: A shape which can be defined by a small number of dimensions and a known shape class. (parameterized formula)

Table Section: A shape which is defined by a table published by a standards organization.

Table Steel Joists: A steel joist shape which is defined by a table published by a standards organization.

Built-Up Section: Defines a complex shape that is comprised of multiple instances of ISM section types.

Varying Section: Defines a shape that varies along the length of the member.

Custom Section: Defines a cross section with a custom geometry shape.

A Revit Family Symbol (more commonly called Family Type) is mapped to one of four ISM Section types:

• Table Section

• Table Joist

• Section Instance (can be any type: Parametric/Custom/Built-up/Varying, except Table Section)

• Joist Instance (can be any type except Table Joist)

Table sections and Table joists mappings are not dependent on the ISM repository to which Revit data is being exported. Rather, these map Family Type with Section/Joist name and name of the Table to which it belongs.

Section Instance and Joist Instance mappings are dependent on ISM repository. These map Family Type with ISM Object Id (object instance id) from the associated ISM repository.

Where are the mapping files?

Mappings information is stored inside the Revit project file, unless you specify elsewhere in the Advanced Operations Settings dialog. Maintaining the mappings in an external XML file is typically only used when you do not have direct write access to the Revit project file. Otherwise, it is recommended to store the mapping information inside the Revit project file (default plug-in behavior).

A separate database file is used to store mapping templates and sets of Revit family files used when automatically matching family types and ISM sections.

See Also:

Integrated Structural Modeling Home