BIM Tutorial

Introduction

Building Information Modelling (BIM) is a digital representation of both the physical and functional characteristics of a building. A good overview of BIM can be found on Wikipedia.
BIM datasets are very complex, and require powerful architecture software to edit interactively. Data can be exchanged between BIM software using the IFC format, which has an open, Ascii based file structure. FME can both read and write IFC. FME can also read directly from the popular BIM software Revit.
CityGML, an open XML based format, is sometimes considered a lightweight form of BIM. FME can both read and write CityGML.
 

BIM Data Structure

BIM data has a complex hierarchical structure. The top level Project contains a Site, which in turn contains Buildings, which in turn contain all the physical parts of those buildings with their own hierarchy. A more detailed description of this structure can be found in the IFC reader documentation.
Attributes can be attached to the features at any level of this hierarchy, and so are read as traits on the geometry instead of feature level attributes. For more information on geometry traits, please refer to the FME Documentation.

Revit

Data Views

The Revit reader provides Data Views, which simplify the complex BIM data for conversion to simpler formats. For example, the Floorplan data view extracts 2D floorplan representations of the 3D BIM geometry. These data views give you a headstart on creating conversions from BIM to 3D, GIS or CAD. For a list of the data views, please refer to the Revit reader documentation.

Plugin

FME uses a plugin within Revit to create an exchange file for the Revit reader. You can find a tutorial on using the FME Exporter plugin at How to use FME Revit Exporter for Revit.

Geolocation

There are two methods to geo-locating a Revit file. You can find a tutorial on working with these methods at Revit Geolocation Tutorial.

Revit Conversion Examples

Revit to Sketchup and Acrobat
This example shows how to convert a Revit model to a simplified Sketchup or PDF 3D model, while retaining as much attribute information as possible.

Extracting COBie information from Revit
This example shows how to extract COBie information stored in Revit schedules to the standard COBie Excel sheets.

Revit Writing in FME Form
This example shows how to assign a new color to Revit elements, and then write these elements to a new Revit project file.
 

IFC

Data Views

The IFC reader does not presently provide Data Views. However, due to similarities between IFC and the RVZ file produced by the FME Exporter plugin, the Revit reader can be used to read many IFC files using Data Views.

GeoLocation

The IFC reader user the Site feature latitude and longitude to create a custom coordinate system centered on that location. This allows you to reproject the IFC data into any desired output coordinate system

IFC Examples

IFC to CityGML - Basic
This example demonstrates a simple translation of a low detail IFC model to a CityGML document

IFC to CityGML - Intermediate
This example shows how to convert from a high detail IFC model to a CityGML document with a Level of Detail of four. The example workspace is comprehensive enough to handle most Architectural IFC datasets.

IFC to CityGML - Advanced
This example demonstrates combining both high and low detail IFC data into a single CityGML document with multiple Levels of Detail.

AutoCAD to IFC
This example demonstrates how to convert 2D rooms from an AutoCAD floorplan to Spaces in IFC.

Updating IFC
This example demonstrates how to convert an existing IFC file back to IFC, while updating some of the Space property sets from an Excel table.