Monday, July 30, 2012


It seems I managed to ruffle the feathers of the good people at Ideate by not making it clear that Michelle's session at RTC made use of their "BIM link", and not the "other product" that I mentioned in my previous post.  This is a shame because I believe them to be worthy members of the global Revit community. 

I felt it was important to pay tribute to Michelle, because her session was inspirational and directly motivated me to do something interesting with the ideas she so generously shared with us.  As far as this blog is concerned, I am in the business of sharing ideas, freely with all & sundry.  It has been a great pleasure over the past year or so to make contact with people from all over this planet who share my enthusiasms.  I do not wish to advertise products or receive inducements.  I still feel rather attached to the old-school notion of professional neutrality that held sway when I was young.  From time to time I have shared my thoughts on the quality of family content offered by a manufacturer.  I try to be honest, but not rude or dismissive. 

Tips & tricks are all very well, but I am more interested in what you want do with them.  Likewise software plug-ins and utilities.  They are just facilitators.  My focus is on the bigger picture.  What do you want to make ?  What fantasies would you like to explore ?  Which aspects of mankind's strange and poignant history would you like to elucidate by means of a data-driven model ?

The idea of using Excel to drive Revit is an intriguing one.  You need an extra little tool to make the link.  There are a couple on the market capable of doing the job.  Do your own research and make a choice.  I have no interest in influencing your decision.  But I would like to share the results of our explorations.  So let's get on with it.

First of all take my curtain panel and make the thickness parameter control the diameter of a hole instead of the panel thickness.  Use a simple formula to limit the size to a reasonable value (R = 150mm + thickness/4 ... for example) Trial and error came in handy here.

That's OK but what if I were to combine this with some thickness variation, all based on the same controlling values ?  That led to a fairly interesting arrangement.  Notice that I have unpinned the glazed panels now and substituted a glazed system panel.  Holes in the glazing looked a bit stupid, and some panels having no holes breaks up the pattern nicely and provides a counterpoint to the orange accents.

Next I tried a slot at one side.  That turned out to be disappointingly unlike anything you would ever want to build, so I introduced a sill piece that also responds to the thickness control.  I also changed the material for the system panels to a wood block flooring texture.  This is getting dangerously close to something I might actually use.  Maybe a ventilated facade for a parking structure ?

Note that all this was done in an evening after work,  AND only involved editing curtain panels.  No further interventions with the dreaded linking software. 

So what happens if I try to re-import from Excel ?  An error message of course, what else ?  But why ?  I am guessing that successive reloads of my curtain panel have played havoc with the unique ID numbers.  So I re-export and attempt to link the two worksheets again.  Impatient to do this quickly so it seems I somehow managed to switch vertical and horizontal.  Maybe that happened during the re-export process.  Practice is obviously needed if you want to control the effect precisely.  In this case I'm gunning for the happy accident, so let's accept the result and move along.

A few more tweaks, play around with different image combinations & I soon have some useful facade options to show to my team leader / partner in charge / client. 

I need to understand the data linking better and work hard on my Revit skills so that the process of linking data between two sheets can be rapidly reproduced.  But I am still quite excited about the hybrid approach: part formula-driven and part manually tweaked.

Thursday, July 26, 2012


So what did I get out of going to RTC in  Atlanta? One of my favourite sessions was Michelle Leonard from Auckland NZ showing off the power of linking Excel & Revit together. Most of the credit for this post belongs to her.  Thanks Michelle.  I was inspired enough to go out and buy myself a copy of Revit Excel Link, a bargain at $95. 

My first experiment is basedon a rectangular array of curtain panels.  It was meant to be 10x10, but by mistake came out as 11x11.  No matter.  I edited the curtain panel family to make "Thickness" and instance parameter.  Now it's easy to select individual panels, or whole rows, and change their thickness.  X & Y parameters will make it easier to locate the panels once exported to excel.  They are all set up as shared parameters so they can be scheduled (and exported to Excel.

Within excel, the parameters come through in vertical rows.  It will be easier if we can see them in a rectangular grid that matches the curtain wall.  I did this by creating another worksheet called "Source", and linking the cells to the "Thickness" column based on their X-Y values.  A1 to A1, B1 to B1, etc.  You can use your excel skills to drag down the little black square at the bottom corner of a cell.  This will propagate A1 down to A11 and give you the relative links you need.

Apply conditional formatting to colour cells so that you get instant feedback on the range of values.  My first trial uses a simple formula that simply adds 50mm to the cell on the left. 

Now import this back into Revit and the curtain wall updates to match.  So it works.  Now for something more interesting.

I learned from Michelle that Excell has a function called RANDBETWEEN.  A little more Excel trickery and the entire array is populated with Random numbers between upper & lower values specified in two cells to the right of the array.  In this case, between 100mm & 3 metres. 

Import back into Revit & you get a nice little message saying all 121 panels have been updated successfully.

Recalculate to get another random array.

Change the values to create an effect that is more subtle or more extreme.  This is fun.

Next I set up a series of vertical stripes with different upper and lower values.  Again these are controlled by cells to the right.

Now I can try out all kinds of permutations and combinations. I can also make the curtain wall into a group and copy it on either side to simulate a building facade.

Then I can use the randomly generated pattern to suggest changes to the material parameter (also changed to be instance based)  I like this, a mixed approach: partly random, partly ordered (the vertical stripes) partly intuitive choices input manually.

The end result is not a real building, just an idea, an impression, a visual fantasy.  But you get the idea.  Link the power of Revit to the power of Excel, throw in a bit of judicious manual intervention ... lots of interesting possibilities.

Wednesday, July 25, 2012


Second week back at work.  It's been hectic, so first post is going to be a mixed bag of memories. 

RTC 2012 USA was brilliant.  First of all the people.  So many new friends and internet connections come alive in the flesh.  I hope I can stay in touch with you all.  A close second, the sessions.  So much to think about.  So many experiments & explorations beckoning.  Can I find the time ?

England was all scattered showers & brief sunny periods.  The usual complaints from the locals, but for me it was a welcome change from the relentless Dubai sun.  Water was the theme of a day out with two old friends from university days.  We visited Cromford in Derbyshire, the site of Richard Arkwright's first mills.  His water frame brought serious mechanisation to cotton spinning, using the kinetic energy of the River Derwent to launch the industrial revolution.

The building themselves are fascinating.  Thick walls with stone exteriors & plastered brick inside.  Splayed reveals to sash windows with wooden lintels.  The floors were the key innovation.  Fireproof construction, based on cast iron beams and shallow brick arches.  In the first Cromford Mill this permits a clear span, but for later & larger enterprises both upstream and down, cast-iron columns permit deeper floor plates.  Wouldn't it be wonderful to have Revit models of these historic buildings made available on the web ?  So much information is freely available these days from Wikipedia to Panoramio, but BIM models would take this to another level entirely.  Make your own walkthroughs, section boxes, sunshading studies, structural analyses.  Bring history to life.

That evening I saw my 3 cousins, who have lived their lives close to Barnsley where we grew up.  Exactly a week before I had played a gig with 2 old school friends from Barnsley Grammar School.  This was the third annual performance of a band that continues to grow and develop.  An excellent example of real-life, intense, face-to-face interactions, made possible by internet-based preparations & support.  Emails fly back and forth, practice sessions are posted on You Tube, song sheets sit in the cloud and the full band meets up for the first time on the day of the gig. 

The final weekend took me to London and some quality time with my youngest son.  Unlike my cousins from Barnsley, my branch of the family has dispersed all over the globe, so these are precious moments.  We visited the Shard, towering above Borough Market.  Context is crucial.  In Dubai it would be dwarfed, just another wierd tower, trying to be different.  But here the play of contrasts is superb. 

London has been doing a great job of inserting new high-tech interventions into historic locations this past few years.  The conversion of the undercroft of St Pancras into a shopping mall has really given this grand old building new life and vigour.  Note the connection to Cromford's mills.  Cast Iron from Derbyshire, which was on the cutting edge of technology in those days, not the quaint tourist backwater of today.

I saw the new insertions at Kings Cross for the first time last weekend.  Just passing through, but they looked impressive.  I think it's appropriate that the additions to St Pancras play it straight: simple and rectangular in contrast to the gothic exhuberance of Scott's hotel & Barlows magnificent arch.  Conversely, the historic context at King's Cross is restrained and business-like, inviting a much more organic addition.

It was not always thus.  Three stops on the Northern Line takes you to Camden Town, scene of one of Nick Grimshaws early forays into Hi-Tech imagery.  Somehow, the blatant facadism of the Odeon Cinema seems to have aged better and to be more in keeping with Camden Town's current black leather goth persona.

On Sunday we took the central line out to Stratford to take a look at the Olympic village, but it was no longer accepting visitors so we had to make do with the new Shopping Mall.  Not sure what to make of the metallic forest.  Seems to be there to distract the eye from the rather bland architecture beyond.  I rather liked the big red hands that were being used as an adjunct to conventional signage.

London's second Westfield shopping centre is very stylish, well up to the standard of Dubai malls.  Check out the slick recycle bins in comparison to Borough Market's plastic eggs.  One thing interests me.  Everyone seems to be agreed that you need 3 bins, but there are different ideas about how to label them.

So to finish I can't resist a tribute to Borough Market's riotous diversity.