It's good to share

  As I have mentioned previously, BIM is about   

  sharing and collaboration. Sharing is easily

  done if all the disciplines are working within

  the same software but on a large project that is

  not always the case. With BIM the disciplines

  are working much closer together and sharing

  data much more often. Sharing of data should   

  be worked out and planed at the start of the

  project and the sharing procedure should be

  outlined in the BIM execution plan. From the initial   BIM meeting each discipline should decide what  software they are using so a comprehensive plan for sharing data can be established. Sharing between the different software’s should be tested to ensure that the best procedures are implemented. When sharing data, data is exported from 1 product into another and sometimes the export/import is not 100% or problems can occur with project standards. If you test your transfer procedures and issues are discovered, then you can look at ways of working around these issues to get around the problem. It’s often hard to know where the problem lies. The problem could be caused by the program that is exporting the data or the program that is importing the data. These exporters and importers are only as good as the person that wrote them and tested them. Just because 2 programs have IFC exporters or DWG exporters they may not both be to the same quality, it depends on how the software development company have implemented and tested this part of the software.

In a lot of projects people use dwg as a format for transferring data between products. This makes sense because all CAD and BIM software import and export dwg. But in the BIM industry if you use dwg you will only get graphics you will lose all the data behind the graphics that has been built up in the BIM model. There is another format which can be used between different software’s. This format is called IFC (Industry Foundation Classes) IFC is not a new format and has been around since 1994. IFC is a platform neutral, open format. It is not controlled by any one vendor. It is developed by an independent company called buildingSmart to facilitate the sharing of data within the AEC industry. In Denmark it is compulsory to use  IFC on publicly aided building projects.

If you would like to learn more about IFC you can get more information from the following links

BuildingSmart:

http://www.buildingsmart.org/

Bentley: http://ftp2.bentley.com/dist/collateral/whitepaper/Building_IFC_Position_Paper_whitepaper_eng.pdf

AutoDesk:

http://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/Revit-DocumentPresent/files/GUID-6708CFD6-0AD7-461F-ADE8-6527423EC895-htm.html

Graphisoft Archicad:

http://www.archicadwiki.com/IFC

If you are working within the Autodesk suite of products, Autodesk has developed a file format called adsk (Autodesk exchange format). This format can exchange data between Revit, Civil 3D, Inventor and AutoCAD Architecture. In Revit you can bring in an inventor file through > Building Component commands. You can export to Civil 3D from Revit through .adskfile format by selecting  Export >Building Site. I will chat about the adsk file format and other Autodesk formats in later blogs.

If you are using Bentley products you can use the Bentley native DGN format. The great thing about the DGN file format it never changes. In all the years I have been using MicroStation it only changed once between version 7 and 8.

If you are using Graphisoft ArchiCAD, Trimble Tekla, Nemetschek All Plan or others you will need to use IFC. Always checkout the software providers website for the latest version of IFC export/Import or other plugins they may have for exporting and importing IFC. For example if you are using ArchiCAD with Revit Graphisoft have a Revit plugin for improved importing/exporting between Revit and ArchiCAD. Check out the Graphisoft website for further details,

            http://www.graphisoft.com/downloads/interoperability.html

To sum up this article make sure you decide how you are going to exchange and share data. Test the import/export and document the procedure noting any issues and work arounds. Share the data regularly through your chosen format so if any issues arise they can be tackled as they arise and you won’t have any surprises when you are under pressure to issue models. Always keep in mind the deliverables for the client and document your sharing procedure. Let all start sharing our data.

If you have any questions on anything in this blog or any other blog please feel free to contact me at dan@siscin.ie

Dan Deery is a director of Siscín which is a company based in Ireland specialising in BIM Consultancy, 3D modelling Animation and Visualisation. Siscín have worked on many different projects across the world. For more info on Siscín and their services check out their web site on www.siscin.ie.

At Siscín we often work on multi-discipline. In    

these projects numerous softwares can be used

such as Civil 3D, Bentley  MX Road/Rail.,

AutoCAD , MicroStation, Revit, 3DS Max etc.

We are often involved in the coordination,

 training, modelling, visualisation or all of the

 above.

The project starts off with the civil/survey data From the Civil/Survey data we get our site, our  levels and we can create our DTM (Digital Terrain model).

If we are using Revit we will use the survey data to derive our shared coordinates. When it comes to coordinates Revit differs from the other software’s. The other software’s mentioned above all work in world or absolute coordinates based on 0,0.  Revit works differently. In Revit your coordinates are relative and your site can not be further then 33km from the origin. Origin is probably a bad word to use, in Revit we call our reference point (origin) the project base point.  When it comes to positioning your project in Revit a lot of people have a mental block. But it is very important that your project is positioned correctly if you want to use setout coordinates, analysis or if you want to collaborate with users using other products.. In today’s blog I won’t go into setting up shared coordinates. I will deal with this in a later blog. But if you want to learn about it now, go online and search for Revit and shared coordinates. If  you are using Revit in your project you will need to pick a reference point on your survey and this will become your survey point or you project base point.

In the last blog I mention the BIM Execution plan. The coordinates of this reference point should be outlined in this document. Not only do you need it for Revit, you will need it to ensure all your models are coordinating correctly. If you are using 3DS Max for visualisations, sight or lighting analysys you will need a reference point because  Max does not use absolute coordinates either.. I will discuss more about positioning your model in 3DS Max in a later blog.

When you have a number of software’s involved in a project good coordination is critical. For example if we take a road or a rail project. These projects can include roads, building, drainage, ducting, electrical systems and many more. You could end up using all of the softwares mention above and more. Careful planning from the start of your project can make the coordination less complicated.

As you have probably gathered from this blog and my last one. Planning and good BIM management at the start of a BIM project is essential. Followed on throughout the project with further management and coordination. A BIM manager or coordinator is must have on any BIM team.

  

If you have any questions on anything in this blog or any other blog please feel free to contact me at dan@siscin.ie

Dan Deery is a director of Siscín which is a company based in Ireland specialising in BIM Consultancy, 3D modelling and Visualisation. Siscín have worked on many different projects across the world. For more info on Siscín and their services check out their web site on www.siscin.ie.