Wednesday, January 29, 2014

Concrete Railings and a Newel Post

I wrote about some concrete railing and balusters in 2008, maybe you remember seeing this image? It's one of several in that post.

I neglected to post a copy of the newel post family. It was a separate family that I just placed so I could sketch railings between them. Over the years I've been asked to share it but until today I couldn't find it. I stumbled across it while looking for something else I made years ago, they were in the same folder though I'm at a loss for why. Regardless I've added it to the list of samples to download in that post and it can be downloaded right here too.

Download the Newel Post (83.5 KB)

Tuesday, January 28, 2014

A Little Quick Area

If I need to find the area within some sort of boundary the first expectation among AutoCAD users is "Where is the Measure tool in Revit?" There is a Measure tool but it measures distance between a couple points or a chain of points. It doesn't deal with Area.

For that we can use a Region, either Masking or Filled. I sketched a Masking Region using an arbitrary boundary within a plan that isn't already clearly defined as a separate room or space that could easily provide an area to me. I'm imagining a quick draw response to my boss looking over my shoulder and asking, "How much area is there between this, this, that and that?" Start region, sketch with the Chain Option on, Finish Sketch - "There is 375.46 SF sir."

I can just delete the region once I've found the answer. If I create the region in a working view (one that isn't getting printed on a sheet) I can just leave it there for awhile so when the boss comes back and says, "How much area was that again?" I've still got it and only need to look at its Area parameter. A floor could do the same thing, same number of clicks and it also knows perimeter and volume.

No it isn't a tool called Measure Area but the task and click count is at worst an extra click, maybe two compared with the Measure Area in AutoCAD. A keyboard shortcut and it's no more effort at all. It's the same only different.

Edit/added: I mentioned in a comment that the reason Area exists/is a parameter for regions is in response to users requesting the Measure Area tool in AutoCAD.

Tuesday, January 21, 2014


Every now and then we get nervous about the results we see in schedules or in dimensions. I received an email a few months ago asking about an error they observed in the length of a wall. They exported from Revit so they could examine the model against others with Navisworks. They saw a wall that is 10 meters long reported a length of 10.000000000001 meters in Navisworks. That extra one would need a lot of friends to add up to something we could actually see with our eyes. It's still worrying?

A thread at RFO today popped up regarding the accuracy that dimensions were showing. In this case the project units were adjust to 12 decimal places too. The dimension was reporting extra info in the 12th digit too. I replied there that it's a floating point math issue. I also wrote that I believed that Revit only calculates to six digits places but limits displaying values to 12 digits. I was wrong and you'll see what Leonid explains if you follow the link in a moment.

Chris replied with some great links, one of which I remembered reading but couldn't recall where (AUGI naturally) at the time. This is one where Leonid and Irwin weigh in on Accuracy (Revit Founders).

Regarding that thread at AUGI I particularly liked Irwin's explanation of the magnitude of the error being discussed. He wrote:
...The difference you are seeing is approximately one part in 10 to the 14th power -- it is around one ten thousandth of the diameter of a hydrogen atom. Revit uses double precision numbers for all calculations (as do all CAD systems), and they are only good to around 14 or 15 digits.

Regarding your concern about angles, if an error of this magnitude were introduced into the angle between two walls, and the length of the walls was the distance from the Earth to the Sun, then the error in the distance between the ends of the walls would be around 1 mm...
These are the other links that Chris shared:

Lahey - Floating Point
Double Precision floatin Point format - Wikipedia
What Every computer Scientist should Know about Floating-Point Arithmetic. Warning Chris says it may hurt your head!

From the Lahey site I found this snippet interesting (with my added emphasis):
...Floating-point representations and arithmetic are inexact, but I don't believe that is particularly troublesome to most programmers. Many input values are measurements, which are inherently inexact, so the question about the output values isn't whether there is error, but how much error should be expected...
And this (keeping in mind these are written from a programmer's viewpoint):
  1. Only about 7 decimal digits are representable in single-precision IEEE format, and about 16 in double-precision IEEE format.
  2. Every time numbers are transferred from external decimal to internal binary or vice-versa, precision can be lost.
  3. Always use safe comparisons.
  4. Beware of additions and subtractions that can quickly erode the true significance in a result. The computer doesn't know what bits are truely significant.
  5. Conversions between data types can be tricky. Conversions to double-precision don't increase the number of truely significant bits.Conversions to integer always truncate toward zero, even if the floating-point number is printed as a larger integer.
  6. Don't expect identical results from two different floating-point implementations.
My general observation is that it is much more complicated than we think it is to codify the stuff we take for granted, so called simple things like a dimension of 4'-0" or an area value like 12.53 SF.

Monday, January 20, 2014

Watch for Users Overwriting a Central File

Last week I wrote a post about the Create New Local option being disabled and what that can mean. In response Harry of Boost Your BIM wrote an example macro to catch us when we try to overwrite a central file with our local file. Can't help but wonder why Revit doesn't catch this sort of transaction already? I don't know if Harry plans to share this macro. He may offer it as part of his new Part 2 API Class at Udemy?

Friday, January 17, 2014

Revit and Your Computer Network

Is my Network optimized for Revit? Maybe? A real answer is more than a brief post can cover. These are a few things to avoid.

  • Put Voice over IP (VOIP)on the same server
  • Put Exchange Server (email services) on the same server
  • Put any other resource hungry applications on the same server
  • Assume that because accessing Word and Excel files work great that Revit will be
  • Buy expensive hardware (like Riverbed equipment) without investing in the implementation of it too
  • Ignore server side patches and updates
  • Trivialize computer networking and technology
For example, I've occasionally run into small offices that are using a workstation as their server (peer to peer). This is usually a bit taxing on its resources and the OS of a workstation is not optimized for concurrent users and sharing data as well as a server OS. It can be even worse if that workstation is expected to run Revit too. If that were the case then I'd expect to run into saving and "access" conflicts quite often.

Assuming we're using a real server for Revit project files we can still benefit from putting Revit projects on a dedicated server. Don't make Revit compete with resource hungry applications or, if using a dedicated server, any other applications. That's a recipe for "muffins that won't rise". Hopefully your firm has a great EyeTee admin looking after your computers and Network. If not, then consider changing your current situation soon.

Thursday, January 16, 2014

Create New Local Option is Disabled

When the Create New Local is disabled one of these four culprits are usually to blame:
  • The file does not use worksets (occasionally to blame)
  • The network connection/resource is busy, or disconnected (likely culprit)
  • Someone is creating a local at the same moment (less often, but happens)
  • Opening a file created in a newer version of Revit (less often) [added per a comment]
  • File is a Local file (user copied a local over a central)
  • The network path at each workstation is not the same as each other (very likely culprit)

This is an earlier post about this issue, it's called Creating a Local File - Clue to a Problem.

These are some other Local File posts.
Local Files - How, How Often and Where
Local Files
Working in the Central File
Why Does my Filename include the word Central?
Local Files - How Often

Wednesday, January 15, 2014

Local File Location

Can a Local File and Central File be in the same folder? Sure.

Revit doesn't really care if a local and central file are in the same folder, as long as Revit doesn't think they are the same file. I do it all the time when I'm doing testing at home. As long as I let Revit create my local file with a unique name it doesn't care where the files are. In a real office setting it doesn't make any sense to put a central file on a workstation. It also doesn't make any sense to put Local files on a server either.

Usually EyeTee wants nothing important on workstation so they can schedule regular backups. The reality is they are getting a backup of the project, the Central File. Local files are nothing more than a "working copy" of the project and they ARE meant to be perishable. If you heed the advice on this blog you are already creating a new local every day or, like me, every time you start work on a project.

Tuesday, January 14, 2014

Visibility Post Summary

This is a collection of posts regarding visibility in a general sense. They are either literally about visibility issues and features or somehow related to "seeing" things.

2015 Temporary View Templates
2013 Stacking Views on Sheets
2013 Elements are not Displayed or Missing (Troubleshooting guide)
2013 Text Editing and Zooming
2013 Workset Visibility and Linked Files
2013 Linked Files and Visibility Graphics
2013 Visibility Graphics Dialog and Using Current View Only
2013 Apply Versus Apply and View Templates
2013 Revit 2014 Schedules Pending Gotcha
2013 Fittings do not Look Right
2013 Why Use So Called Working Views
2013 View Discipline

2012 Applying Visibility Graphics Overrides
2012 Filter Pesky Levels
2012 Linked Files have Instance and Type Parameters
2012 Hide those Connectors
2012 View Range Redux
2012 Visibility Pecking Order
2012 Scope Boxes
2012 Color Fill Legends Mixing with Stairs

2011 Printing with Temporary Hide Isolate
2011 Revit Links as Underlays
2011 Control Visibility of Image via Size Parameters

2010 Managing Visibility of Linked files
2010 Workset Visibility in Linked Files
2010 Guide Grids
2010 Smaller Grids in Large Scale Views

2009 Video Four View Range Top Offset
2009 How View Range Affects Various Views
2009 Where did my Mass Go

2008 OK and Apply
2008 Aaah the old Invisible Line Trick eh 99

2007 Sketch Lines and Visibility Graphics
2007 visibility of Grips
2007 Shaft Opening and View Range
2007 Future Phases

2006 Workplane Visibility Tips
2006 Workset Visibility in Linked Files
2006 View Range and Floors

Friday, January 10, 2014

Schedules can be in a Group

Alex at RFO mentioned in a thread that he has created a Group with schedules on sheets to help manage them when he needed them on more than one sheet. I wouldn't have thought it was even possible and I probably wouldn't have thought to try that even if it occurred to me.

Schedules that are on more than one sheet can end up in different locations so a Groups origin could make it a bit easier to ensure a schedule or schedules are arranged the same way from sheet to sheet.

Something to think about, hat tip to Alex!

Thursday, January 09, 2014

Show History and I am Working in Central

We can use the Show History feature to see the save history of our project. If worksets are enabled we'll be described as Working in Central if we are also using Worksharing Monitor. This happens if we browse to the central file to access the save history. If we do this while working in a local file we'll be listed twice in Worksharing Monitor, once for your local file and another for the central.

No worries, we are not really in the central file, at least not in a position to save or alter anything. Review the history and close it when done, no harm done.

Wednesday, January 08, 2014

Always Unless - Interacting with Dimensions

It is fun to tell someone how to behave with elements and dimensions in a project and then the next day talk about the family editor and contradict that advice.

For example in a project we select an element like a wall and then interact with the dimension value (permanent or temporary) to move it. If we select the dimension first we end up in the Dimension Text dialog instead. Revit thinks we want to override the dimension with text or add a suffix/prefix.

In the family editor however we can select a dimension that has a parameter associated with it and interact with the dimension value directly to change a referenced element's position.

Just remember, It's the same only different or It's always like this except when it isn't.

Tuesday, January 07, 2014

Voids and Material Orientation

When we use a void to cut a solid sweep it will affect the orientation of a material applied to it. Here's a sweep that is not cut and has a wood grain material assigned to it. I've got a void poised to cut it.

Here's the orientation of the material after using Cut Geometry.

This happens to a sweep but not an extrusion. The material sort of flashes when Cut Geometry is used but it doesn't change the orientation of the material.

If we create a Revolve solid and apply a material it will look like this when we use the End Angle setting of 180 degrees (or 360).

When we change the angle to 45 degrees the material orientation changes.

Then this happens when we apply a void using Cut Geometry, it fixes the orientation. Well it fixed the orientation of the "dome", not the "steps".

Quirky squared by subtle

Monday, January 06, 2014

Double Up on Keyboard Shortcuts

This is lifted from the RFO Tips and Tricks forum and a contribution by Mark Balsom. He's reused the same letter combinations to deal with starting and finishing sketch based elements. For those who are unaware (or not) you can assign the same shortcut keys combination to more than one command.

For example, assign EE to EDIT "...x..." as in Edit Boundary and Edit Profile for example. Keep in mind we can just double click on sketch-based elements to accomplish the same thing now (in 2014).

You can do the same with FF for FINISH instead of clicking the Green Check Mark.

You can do the same with CC to CANCEL instead of clicking the Big Red X.

In use it looks like this:
  • Select a floor, type EE (Edit Boundary), type FF when you are finished
  • Select a wall, type EE (Edit Profile), type FF when you are finished
  • Select a roof, type EE (Edit Boundary), type FF when your are finished
  • ...or if you decide to cancel the current sketch based editing session, type CC (Cancel "...x...")

Here's an extra tip
You can also Cycle through (review and select one) all the available commands that are associated with the first letter of a keyboard shortcut. Type a letter and look at the Status Bar. Revit shows the first command associated with that letter. In this image you can see what happened when I type Z.

Use the left/right arrow keys to Cycle through any other commands that also share that first letter. It cycles through (displays the commands) them in alphabetical order.

Saturday, January 04, 2014

Autodesk Robot Structural Analysis Book is Available

Ken Marsh published his first book dedicated to Autodesk' Robot Structural Analysis Professional 2013 (it's also the first book for it). He intends it to be your essential introduction to its features, functions, and workflow. He's confident that you will be able to master the tools you'll need to make Robot work for you.

Some of its highlights include:
  • Demystify the interface
  • Manipulate and manage Robot tables like a pro
  • Learn how to use Robot's modeling tools
  • Master loading techniques
  • Harness Robot automated load combinations
  • Decipher simplified seismic loading
  • Discover workflows for steel and concrete design
  • Gain insights to help troubleshoot issues
He's prepared easy guided exercises to help get you up to speed quickly.

Ken is a structural engineer and was, until recently, the Revit Structure Quality Assurance Analyst at Autodesk. He works hard to be a champion of Building Information Modeling (BIM) technology for the Architecture, Engineering, and Construction industry. In addition to writing this book he is currently working to promote fully integrated structural analysis, design, and documentation by developing custom Revit API add-ons, providing software training, and consulting services for firms as they transition to a more fully BIM-centric process.

I appreciate and admire his willingness to write about a topic, that must be a niche among niches, catering to structural engineers. I was also curious about whether a 2014 edition is going to be available, he replied that he's working on the 2014 edition now.

All the best with the book Ken!

Friday, January 03, 2014

RTC Events Calendar for 2014

The dates and locations for the next three primary conferences and three adjunct events are as follows in the order they will occur in 2014.

RTC DTS FEB 2014 (Design Technology Summit)
(Invitation Only)
Location: Denver, CO, USA
Venue: Westin downtown Denver
Dates: February 5 (Wednesday) - 7 February (Friday), 2014

RTC VisCON 2014
Location: Melbourne, Victoria, Australia
Venue: Pullman Melbourne Albert Park (same as RTCAUS)
Dates: May 26 (Monday) - May 27 (Tuesday), 2014

RTC Australasia 2014
Location: Melbourne, Victoria, Australia
Venue: Pullman Melbourne Albert Park (same as VisCon)
Dates: May 29 (Thursday) - May 31 (Saturday), 2014

RTC DTS JUNE 2014 (Design Technology Summit)
(Invitation Only)
Location: Schaumburg, IL (Greater Chicago)
Venue: Renaissance Schaumburg Convention Center Hotel (same as RTC NA)
Dates: June 16 (Monday) - June 17 (Tuesday), 2014

RTC North America 2014
Location: Schaumburg, IL (Greater Chicago)
Venue: Renaissance Schaumburg Convention Center Hotel (same as RTC DTS June)
Dates: June 19 (Thursday) - June 21 (Saturday), 2014

RTC Europe 2014
Location: Dublin, Ireland
Venue: (a royal venue, tba soon)
Dates: October 30 (Thursday) - November 1 (Saturday), 2014

Please mark your calendars accordingly. Hopefully you will be able to attend one, a couple, several or even all of them. I'm looking forward to seeing old friends and making new ones at these events in 2014!

Thursday, January 02, 2014

Copy Monitor Walls and Openings

I've mentioned in the past that we need to be careful using the Copy/Monitor (C/M) tool on walls when we use the option Copy windows/doors/openings.

When Revit examines the geometry of the family used to create the opening in the C/M'd wall it looks at the overall geometry to define the opening's size. That's usually not good because trim on the face of the wall does not define the opening required. The stock door families (and windows) are good/bad examples of this in action.

This is an opportunity to bring up another advantage of creating doors like described in A Door's Life, they behave when you use C/M. Why do they behave? There isn't any native geometry in the host door family. The frame, door panel, swing and hardware geometry are all based on nested families and the C/M tool doesn't "see" them when it creates the equivalent opening in the C/M'd wall.

Here's a comparison based on stock and not stock doors, in plan view.

The openings created from the stock doors are as large as the trim elements that surround the opening of the door (3" wide trim). The openings for the not stock doors as as large as the opening in the host family and all the nested components are designed to fit inside the opening that's used in the family. The nestedness of all the components prevents them from being detected by C/M.

Here's the elevation of the same doors.