Monday, 22 August 2011

Do you find Revit puzzling?

This post isn't a tip or workaround but more a simple observation which has stuck in my mind. 

During a typical working day I get lots of questions from team members regarding their Revit projects.. Some the answers I give them are quick fixes, some are simply advice tips however some are simply bad news. 

As I'm sure many of you already know, Revit can be amazing at doing complex tasks and yet sometimes it can seem almost impossible to get it to do something that the user considers a simple task. In actual fact, this is more often than not a user issue rather than a Revit issue. When this kind of thing occurs I can usually find a workaround to achieve the desired result but it often comes with bad news for the deadline panicked user.

Usually these issues are a result of a lack of forward planning when it comes to building the model or sometimes it can be a change in the user's requirements of the model. (these can be the same thing).. When this happens you often have to unpick a lot of work to be able to be able to provide a fix.. Users don't tend to like this and I often find myself the bearer of bad news.

In a recent such case and after explaining an open-heart surgery procedure for a live Revit project a colleague of mine summed up the whole thing in a nutshell. He said that it reminded him of doing a slider puzzle...

You know the one where you almost get it completed but the last two squares are the wrong way round. The only way to get it right is to go back and tear up what you have just done and rework it. Well guess what.. The same applies to your Revit projects..

Actually, I rather think a Revit Project is more like something like below but you get the idea.

I guess the lesson is to try and start with the end goal in mind. Please dont just jump in, whilst you may well get 1-13 done in record time I can guarantee you will be doing it again tomorrow if you want 14-15 the right way round.. 

Thursday, 4 August 2011

Beware of the Dimensional Rounding

This is an interesting issue i have come across on a number of projects now and therefore one i thought worth posting about. Its symptoms include not being able to dimension elements horizontally within sections. For example, your section cuts perpendicular through a wall however for some reason you cant dim to the wall edges.
To make this worse, you can see your Gridlines in section but if you try and dimension to them you get the following error message:


As the message suggests, this can be pretty serious.

This pretty much ALWAYS caused by the section not being perfectly perpendicular to the gridline. What is odd about this is the fact that Revit actually displays your gridlines even if this is true.. How can it if the view is not perpendicular? My guess is that Revit has some element of tolerance when it comes to this. The problem seems to come because the dim tools don't appear to have ANY tolerance.

So lets check the theory:

Within the file above the first thing i looked at what the relationships of the grids to each other. I threw a few dims on and it all appeared fine.

Check 01

The thing is, i have seen this a few times before so i knew what was happening here. The key is to be aware of the decimal rounding which the dim styles is applying to the angular dims in the image above.
To check I went into the dim settings via the route highlighted below:

Dimstyle -1

Initially the dim style was set to use the project settings. This was rounding to 2 decimal places.
To check the true angles of the dims i set the dim style to Degrees, Minutes and Seconds.

The results were as below:

Check 02

Oh dear..

This is the equivalent of the being 0.0001 degree out.. Seems a bit harsh doesn't it but the fact is it is incorrect.
Now the fact that the grids are not perfect is not strictly the problem here but it is the cause. In truth the crash is caused by the fact that the section is not at exactly 90 Degrees to the intersecting gridline.

Of course the correct thing to do here would be to check and adjust the gridlines and all the other geometry within the model but this is not always viable. If this error is caught early enough correcting the grids may be viable. However as is more often than not this error is not found until weeks into a project.

I guess the lesson learnt from this would be to use Degree, Minutes and Seconds as a basis for angular dims, at least for the initial project setup.

I do have a work around to ensure that sections are perfectly perpendicular to a gridline. I will try and cover this in my next post.

Wednesday, 8 June 2011

Modelling Floor Finishes–The FAST way!

Well, after a little Twitter banter between myself and David Light last night regarding modelling floor finished I appear to have spent the day trying to figure out how we can model floor finishes within our projects efficiently. I say efficiently because this is something we have tried before but found it to be pretty labour intensive and a little too similar to polylining in AutoCAD for my liking. Previous attempts of modelling floor finishes using thin floor types proved painfully slow and inflexible.. Whilst this approach did achieve its purpose of providing us modelled floor finishes it entailed endless updating when things changes such as wall build-ups. When this happened we had to modify the sketch of the floors to match the new wall face (and yet we could of locked it but i hate locking the model down too much).

The alterative to this would be use the room parameters to provide floor finish information which is ok but only gets you so far. As soon as a room contains more than one finish (which they almost always do) this method either becomes overly complicated or else breaks down completely.

So, my cunning plan is to model the floor finishes in each room like the floor type method but this time using ceilings instead of floors…. Yes, that does sound a little daft i know but honestly, I think its going to work a treat and here's why.

When using the ceiling tool, Revit has the great feature called Automatic Ceiling. This allows the user to simply click a room and the ceiling sketch will be applied to its perimeter. The best thing about this is the fact that these ceiling sketches are dynamically linked to the room’s bounding elements.

For some unknown reason Autodesk have not yet included this feature in the flooring tools which is why using ceilings the ceiling toolset will save you hours!.
To use this method simply create yourself some new compound ceiling types making sure you move the finish from the underside to the topside. Adjust the makeup to suit your floor types.

With the new (ceiling) floor type made jump to a floor plan and hit the Ceiling tool. Before you actually create the ceiling first check where you are placing it. Make sure you set the offset from level to 0 and untick Room Bounding. One big advantage using a ceiling rather than a floor is that you don't have to worry about offsets. Ceilings are set by their underside whilst floors are set by their topside.
Now simply add the ceiling using the Automatic Ceiling function by selecting the room. This is a really quick way of modelling floors within rooms.
If you need two finishes in room model the primary finish as above but then add the second type on top of the first ensuring the top surfaces are level. You can then user the Join Geometry tool to effectively cut the secondary finish from the primary. When doing this ensure you select the cutting object first.

Not only can you cut one finish out of another but you can also use the floor finishes (ceilings) to cut recesses into slabs where required. Barrier matting would be a good use of this.

Barrier Matting & Slab


Slab cut by Barrier Matting

From Revit 2011 onwards you can also take advantage of the new Realistic View settings to give you real world material representations as well as traditional hatch based views.

Hidden Line:


As well of all the plus points highlighted above perhaps one of the most important things about this method is the fact that we can now accurately schedule out floor materials by type, hopefully putting a bit more “I” back into BIM.

Its important to note that the whilst the schedule does take account of elements cutting each other it does not account for the sections of finish within the door openings. I guess you could update the sketches to pick this up once the walls and door positions are frozen if you wanted to be super accurate..

Finished product. (including a schedulable rug!)

All in all, I’m thinking this is a pretty good workaround, now i just have to try and persuade people at work to give it a go.

Comments welcomed.

Friday, 6 May 2011

Fake Revision Clouds in Revit

Well, I said I would post didn't I so here it is:

Ever wanted to add a revision bubble to a drawing in Revit to highlight something on a drawing but not actually add a revision to the sheets? Its one of those things that we used to do in AutoCAD but Revit seems to be almost too smart and doesn't let you do it. A good example of this would be say if you wanted to highlight something on a drawing is in abeyance. Well Revit;s detail line tools don't have a cloud option but there is a nice workaround.

  • Use the standard Revision Cloud command from the Annotate tab to sketch your cloud.

  • Before you finish the command, select all the cloud lines and copy to clipboard using the button highlighted below.

  • Now cancel the command using the red X. You will get the following dialogue box. Hit yes.

  • Now, from the Annotate tab select Detail Line, and rather than try draw the cloud simply select Paste Aligned to Current View from the Paste button drop down which is accessed via the little arrow highlighted below.

  • Hey presto, Detail Cloud lines as requested and no actual revision on the sheets. Nice.

I wish I would take credit for this but in actually fact it was my colleague sat next to me who figured this out today. Nice one Nat. :) 

Back in the Seat...

Well, its been a LONG time.. I hadn't realised just how long its been.. I suppose I have just been super busy on the work front and super lazy on the blog front but this week I was kind of shocked back into the blog world when I met a friendly gent at a BIM meeting in London. He introduced himself to me and said he recognised me from this blog...I was a little shocked but pleasantly surprised to be honest. I was beginning to think that the only person who looked at this was actually me but it would seem that I do have some viewers. So that got me thinking,, I should really make more of an effort to keep posting and building the blog.. So here I am..

So a big thank you to David Wood of Chapman Taylor for giving me the nudge I needed .