Tuesday, November 10, 2015

Keeping your PDF’s in check – an absolute necessity for successful BIM-ming on any scale

The long overdue third instalment of my ‘The role of PDFs in BIM’ trilogy

Let me start with a long-winded explanation on, how this post is not supposed to be an argument based on the question of ‘why would one want to import one (or hundreds) of PDF file(s) into any working BIM model?’.

There are two reasons for me wanting to avoid this argument, one being that, those in the know will fall neatly on either side of the argument, strongly believing that to be totally unnecessary or an essential capability of the BIM toolset they use. And no amount of questioning their stance will likely to move them from it.

The second reason is that, I do have a lot of dear friends and colleagues that are avid Revit users who will feel somewhat personally attacked by the notion that this question could be the absolute key issue of almost anything BIM – considering their beloved toolset’s inability to deal with it. There is little point in undermining those personal relationships of mine and to reinforce my goodwill and intentions it I’ll admit to the Great Truth of BIM, again, and again –
‘Autodesk rules the BIM world. Revit is the King of BIM!’.

Now, can I get on with exploring PDFs in BIM models?

Through my work I build BIM models from other people’s designs, either during the official design process, following it as part of preparing construction tenders, parallel to building the real thing or even post construction for settling residual claims between parties.

I am a hands-on modeller and my speed, accuracy and ability to deduct useful information based on the model is highly reliant on how I can make use of the hundreds and thousands of PDF documents that are available for the stage/project I am working on.
These PDF’s, needless to say are always prepared by others and never with the view to make my life easier, so even before they get into the model, they must be scrutinised, analysed, weeded-out and ordered.
Once that is done I usually end up with still a large number of files wanted to be imported and while it is a tedious process, I like it as it helps me get to know the project.
ArchiCAD is my tool of choice and I really enjoy how it handles PDF’s within its BIM models.

Here are 10 of the features I can list from the top of my head:
(yes I know…why would you want to bring in a PDF, when a DWG will do and it slows down the file and makes it unusable and…. – let’s just for a minute accept, I LIKE bringing PDF’s in my models and just for a minute, let’s  savour these little clever tools);

1.       ArchiCAD imports PDF’s as Drawings (as opposed to images)
2.       While importing one can choose on the fly any page from a hundred (thousand) page document.
3.       Once imported the file can be resized, or shaped any way one likes (i.e. creating nods and curving edges and offsetting and whatnot)
4.       Literally hundreds of sheets can be imported and kept linked up with no noticeable impact on file-speed and/or agility.
5.       ArchiCAD allows one to use the Trace&Reference with PDF’s the same way as with any other drawing element.
6.       One can ghost a plan behind a section (real or PDF-ed) or a detail in-front a relevant section.
7.       One can use colours on the PDF’s
8.       And/or make them transparent (at varying degrees);
9.       One can slide between the ghosted views and the views can be moved within references without physically relocating.
10.   The files stay linked and it is very easy to update even when moving between various media (like memory sticks).

I am sure there are other neat little features that ArchiCAD has for dealing with PDFs that I am missing here, but I really wanted to concentrate on the ones that I use daily.
I sometimes question myself, if I HAD to work on a BIM model and not have these features available would I get by?
I sure would – but man, would I hate it too.
I guess also that I would  only hate it because I have had the experience to model ‘with the features available at hand’ – otherwise, one does not miss what one does not know.

So, to sum it up – this post is to state, that like it or not, PDFs are and will be for a long time part and parcel of any BIM related activity (trust me, I work in the real AEC).
And sure, Revit is still the King.



3 comments:

  1. 11. Different versions/revisions of the same PDFs can be imported on different storeys, and compared using the Reference sliders

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  2. Hi Zolna

    Interesting your comments re Revit and pdf files - I find that Revit has trouble reading AutoCAD files with an acceptable level of fidelity. It is as though they have stopped developing the basic things that matter to day to day users. Linking to pdf files would be very useful (We currently pdftk the pdf to 300 DPI png files and link these into Revit as images - all a bit clumsy.

    All the best


    Kerry Thompson

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  3. ArchiCAD has great pdf and underlay tools. It is a pity that most authoring tools create particularly crappy vector information. It is a pity that most PDFs are not to scale and that the scale factor is generally inconsistent.

    If your pdf has a disclaimer to not scale off it, and you use the doc to arrange your components, are you in a 'safe' practice area? In this world of disclaimers where .dwg files now come with 'please do not scale' nonsense, 'BIM' tools are making the design world more murky, with no one taking responsibility for their design. pdf only carries design intent.

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