In-Depth with ArchiCAD 14 – Graphisoft talks to Architosh

Continued from page 1

Turning IFC Technology Into Real Workflow Solutions

Graphisoft has developed, in ArchiCAD 14, a plugin structure to streamline and enhance the model exchange interface via IFC (Industry Foundation Classes). It has also developed a plugin for Revit customers who are working with ArchiCAD-based architects. In total, ArchiCAD customers have the option of exchanging data via IFC translators, Add-ins (like those for Revit), gbXML and other traditional means of import/export.

Getting more in-depth with this we learn that Graphisoft has added new properties such as “IFC Element Type” and “Structural Function” to BIM model elements, enabling more refined model mapping between architectural and engineering BIM models.

04 - New IFC element types enable "model filtering" so that only the structural or HVAC components, for example, are exported out to IFC.

Architects can now apply model filtering using these new “properties”, thereby quickly generating just the pertinent aspects of the BIM model to export out to consultants, whether this be structural components or MEP components. This is important because although architects and engineers work on the same structures an architectural BIM model has completely different requirements from a structural BIM model and vice versa. When these components (say structural) come back to ArchiCAD 14, via an IFC import process, elements that are new, modified or deleted get color coded so that architects can quickly see what is new. (see images 04-05 above and below)

05 - This structural BIM model was modified in Revit Structure and then imported back into ArchiCAD 14 via IFC. Color-coding designates new, deleted or modified element.

Let’s take a closer look at how elements can be classified via the new IFC settings. The model shown above is actually the Microsoft Campus building in Hungary. It was used in training materials for ArchiCAD 13 and possibly 12 if memory serves. We see again above and below.

For the most part ArchiCAD 14 is intelligent enough to determine what elements are structural or non-structural and an “automatic” setting is recommended as the default for IFC Element Type. Still, architecture being infinite in its expression some elements may need deliberate designation setting options. To make the point of how this works we’ll just look at three images below. In the first one on the left (image 06) we see “model filtering” in action showing quickly all the elements of the BIM model that are designated “structural.” However, the suspended ceilings have been accidently included in this “structural BIM model” and they don’t want to be.

06 - Changing a component's IFC Element Type Settings.

07 - Changing the Ceiling from "Automatic" to "Ceiling."

08 - Setting an element's IFC Structural Function.

To fix this we visit the Slab Selection Settings palette and at the bottom are the IFC classification drop-down menu options. In the next image (middle, image 07…please click on these to see them larger) we are going to change the IFC Element Type from “Automatic” to “Ceiling.” Then we will change the Structural Function from “Undefined” to “Non-Structural”. Using “model filtering” only elements designated as “Structural Element” end up in the IFC model file bound for Revit Structural. (see image 08)

Graphisoft’s ArchiCAD 14 isn’t just newly savvy with structural integration. The new version also now includes plugins for Revit MEP as well. This allows direct export of Revit MEP models into ArchiCAD MEP Modeler. MEP objects preserve their parameters during export. This means you can manipulate the ductwork parametrically in ArchiCAD 14 (see image 09 below).

09 - Revit MEP models can be directly imported into ArchiCAD 14 MEP Modeler with Graphisoft's direct-connection plugins.

The specific improvements with IFC interoperability exchange with ArchiCAD 14 include items like the ability to not just apply model filtering but export or import specific elements including 2D elements like text, annotations and other 2D elements, such as grids. There is also new support for ZIP compression of IFC files built in because BIM models get large and this helps with the demand to email IFC files.