BILT Speaker

BILT Speaker
RevitCat - Revit Consultant

Thursday 18 April 2019

Path of Travel - The Dalek of Revit 2020

Path of Travel - New Feature in Revit 2020

One of the new features that is particularly relevant for architects is the 'Route Analysis' tool.  This works by placing point-to-point lines between the start and finish of a route in plan.  Revit will then analyse this and find the shortest route between the points, avoiding obstacles on the way, and it will place a segmented detail line along that path, in the chosen view.  The intention for this tool is to create such things as:
  • Fire Escape plans
  • Emergency Evacuation plans
  • Life Safety plans (USA)
Here follows a detailed analysis of the new feature:

Analysis of Route Analysis

The tool is found on the Analyse tab, called 'Path of Travel'

Once the tool is activated, the ribbon displays a Linestyle choice.  It defaults to a linestyle called 'Path of Travel Lines'

Step one is to draw a line between two points.

 Revit then thinks a moment and places a 'Detail Line' segmented pathway between the two points

The first thing you'll notice is that its really hard to see.

This is because the default linestyle is not set to what you'll most likely need.

Path Linestyle

The default linestyle is system defined, but unfortunately its name is not enclosed in < > brackets, so its likely to get lost in amongst many linestyles.

Go to the Linestyles dialog to change its global settings (Not to 'Object Styles', which might be your first instinct) - it  is after all, just a detail line.

  • Note that it cannot be deleted or renamed. 
  • You can change its Weight, Colour or Pattern
  • In this case I've just bumped up the weight to something really visible

You can also create some more linestyles to use for different kinds of paths - this is the nearest we'll get to creating 'Types'.

In this example you might want to distinguish between an escape path to Outside vs to a Stair:
  • The original line can be changed to 'Path to Outside'
  •  A new line 'Path to Stair' could be added

  • Revit will again calculate the shortest path (around furniture/fixtures)

 Notice how hard it is to read the direction of the lines. 

  • Sadly there does not appear to be anything the user can do about the dot at the start, or the arrowhead - neither of which are very distinguishable with heavy lineweights at any scale above 1:50 (is that 1" to 48' in imperial?).
  • Overlapping lines can be moved Backwards/Forwards

Update Paths

If the underlying geometry is changed, you may want to update the path

  • Select a path
  • Click on 'Update Path' on the ribbon
  • Revit will recalculate it

Move It 

I am quite sure this was not the design intent of the update command, but it serves to demonstrate some weird behaviour:

  • Select a path
  • Move it
  • In this example I moved it partially out of the building (keeping the ends inside)

  • Try the 'Update' command
  • It may or may not work

  • This may be your first experience of a very unhelpful warning that does not tell you why it cannot update the path
  • My instinct told me to try again, with the whole path kept inside the building

  •  This time it worked

  • A gold star to anyone who noticed that the path did not avoid all of the furniture - even on the very first attempt

Split Levels & Dizzying Heights

You may have noticed that this example is the Autodesk sample file - a perfect vehicle for testing, as it has a split-level plan:

  • The living area is 3 lower than the rest of the house - and this is where Revit has failed to pick up the obstacles.
  • The question is, does the furniture project high enough to interrupt the path?
  • A section shows that it should - just.

Just to be certain, we should check the calculation heights:

  • Click on the tiny, tiny Route Analysis settings arrow

  •  The lower height is set to a default value of 203.2mm (8") above the view associated level (upper part of split level)

  • This may be just above the furniture, so I tried dropping it to zero, then 'Update' the path
  • Computer says 'No'

  • Then I tried just above floor level, say 10mm, but it still failed
  • The lowest level it would let me go without failing, was 175mm, but it still did not pick up the furniture on the lower floor.

 I then set the lower height back to 10mm, and tried a new path:

  • This time the message was a bit more informative:

I still don't know what the problem is, but it is a bit of a worry that the Autodesk sample file has uncovered a problem or limitation in the software so easily.  I'll update this section when more information comes to light, from Autodesk.

[Edit - it seems that the only part of the sofa high enough to be in the analysis zone is the sofa back, which explains the initial problem - but does not explain why the update path does not work when you lower the analysis zone - Refer to this blog post for more detail]

The Dalek of Revit 2020

Whovians would already have guessed that these paths of travel cannot go upstairs (or down).  That is certainly going to be a limitation for some situations, not the least being split-level plans.


Each Path that you place has some interesting system instance properties

  • Strangely there is no 'Comments' property.  This is very unusual, as almost every other element type does have a system Comments property that can be used in almost any situation (Filter, tag, schedule, key schedule etc)
  • The only properties that a user can change are the Line Style and Mark
  • Time = Calculated time it takes to walk from the start point to the end point of the path of travel. Walking speed is set to 3 mph/1.34 mps (Read only)  [From help file - mps presumably means metres/second.  I'd prefer 5 kilometres /hour]
  • Length = Total length of all segments of a path (Read only)
  • The system properties can tagged

  •  And scheduled

  • From Room and To Room properties are labelled as 'Not Available'.  In the Autodesk help files, they are labelled as 'For Future Use', which is a promising sign for something to come.
It is possible to add your own Project Parameters to Path of Travel lines
  • These must be instance properties
  • If you try Type properties, the Lines category is not available

View Filters

View Filters can access the all the same system properties (except Count)

  • Path of Travel Lines can be filtered by such things as Length, which would be very useful for highlighting paths over specified limits.

  • Path of Travel Lines can be filtered by Linestyle, for separating different kinds (in the absence of Types)

Since Path of Travel elements are actually Detail Lines, they are view dependent, so it unlikely that you would want to hide them in a view, so its more likely that you would want to override properties.

However, you could just do that with Category overrides - so I am not sure you would use view filters for this, unless you want them with halftone.


The settings menu lets you remove categories from the calculation.  By default the door category is removed (checkbox ticked).
I would like to see the standard filtering ability for the category list (its missing from the dialog box)
  • By Discipline
  • Show only selected

Path of Travel Calculations

The Autodesk Revit Help Files have a section describing how the paths are calculated.  I am not quite sure I understand it all - particularly as it only seems to be talking about plans, rather than how it checks for obstructions in 3D.
Path of Travel Calculations


This is obviously a first pass at what should be a very useful tool at some time in the future.

I am very pleased that it seems like Autodesk have been careful not to tailor this tool to any particular country or style of doing Escape Plans / Fire Safety, which is a very good thing (NB. Area plan calculations are a real pain for anyone outside the USA, as an example of country specific coding).  In fact the tool is sufficiently general that it could probably be used for all sorts of other purposes.  Presumably the tools have been made available in the API so that developers can create country specific addons?

In its present format, it does have quite a few limitations, which will hopefully be addressed in future iterations:
  • The Dalek conundrum - how to get up or down stairs
  • No system 'Comments' property.
  • Type properties not available (in Project Parameters, or anywhere else)
  • Users nominate Start point and End point - it does not allow us to nominate any intermediate points that we want to go through.  
  • Perhaps Autodesk could create a way to link paths to allow this?
  • It is not possible to move either the start or end point individually - it seems like you have to recreate a new one if you get it wrong first time. 
  • What happens if you don't like the route that algorithm has chosen as the shortest route?  You may have good reasons for not wanting that route.  I would like to have the ability to either choose another option (Like Google Maps directions), or else to be able to nominate intermediate points, or even to be able to drag individual joint nodes between each segment.

Cartoon - With thanks to Birkett (Punch Magazine)

More On Path of Travel

Improvements to Path of Travel in point releases:

Tuesday 16 April 2019

Revit 2020 and Dynamo versions

I recently installed Revit 2020, and the incorporated Dynamo install has changed significantly to previous years.

Well, it seems to have installed Dynamo 2.1 with Revit 2020, and I am please to report that it left earlier versions well alone.  I had Dynamo 1.3.3 installed in Revit 2017, 2018 & 2019 - and all of those appeared to be intact.  There is some more information on this here.

 New Feature:  Integrated Dynamo Revit 2.1 into Revit 2020

On the Autodesk Blog and Youtube channel are a whole bunch of videos about new features - this included one about Dynamo, entitled "Integrated Dynamo Revit 2.1 into the Revit 2020 release".

As of  15 April (USA) or 16 April (Australia), the video has been removed - I believe that is because its description about supporting Dynamo across multiple versions of Revit is a little confusing.

What the original Autodesk release Video  said is:
  • "You will not be able to update or use a different version of Dynamo with Revit 2020."
  • "This will greatly simplify the installation process and versioning for Dynamo Users."
  • "With this unified experience, you will have Dynamo 2.1 installed at launch and this is tied to Revit."
  • "As the product team release updates for Revit, this is the only way Dynamo will receive updates."
  • "Running any version of Dynamo other than 2.1 will be unsupported moving forward." 
  • "One version of Dynamo will not be supported across multiple versions of Revit."
The last two item are the contentious and confusing ones, and hopefully will be clarified in the near future.  The implication was that you would have to upgrade all of your graphs to Dynamo 2.1 to run under Revit 2020 - hopefully this is not the case.

Whatever the outcome, this is a big change to how Dynamo upgrades are managed.  In the past it was very difficult for users to manage the different versions on different Revit versions - let us hope that this will greatly simplify the process in the future.  I think this will be a really good improvement to the install/upgrade process for Dynamo.

Dynamo / Revit Version Compatibility

No doubt we will still have an overlap period of a few years while we switch to the new system, where we need to keep an eye on which Dynamo version is supported by which Revit.

John Pierson has created a very useful chart to keep track of this, over on his Sixty Second Revit blog.

It appears that any Dynamo graphs created in version 2.02 should still run under Dynamo 2.1 (in Revit 2020).  Anything created in Dynamo 2.1 might work in earlier 2.xx versions, but no guarantee - apparently graphs created in 2.1 do open in 2.02 (Revit 2017, 18,19), albeit with a few minor glitches  see this forum thread.

What it may mean is:
  • If your office still supports Revit 2016, you'd need to maintain Dynamo 1.3.2 versions of graphs.
  • For any Revit versions from 2017 - 2019, these should still work (with the same Dynamo version, or 1.33 or 1.34)
  • If you are lucky enough to be supporting only Revit 2017 and later, you have a choice of Dynamo 1.3.4  or Dynamo 2.02 (or later when available)
  • We don't yet know what the last version of Dynamo will be able to run in Revit 2017.
  • At some point you will need to move from Dynamo 1.3.4 to 2.xx - if you are thinking of rolling out Revit 2020, now is a good time to make that change.
  • Once you have all your Revit versions running with Dynamo 2.xx installed, life should be easier - as you may only need to maintain one version of your graphs (TBC), even if the versions of Dynamo are slightly different. 
  • It might be wise to develop the graphs in the older Revit version that you are using - say 2018, then they are more likely to be forward compatible than being backward compatible if you developed them in Revit 2020/Dynamo 2.1.
  • All that . . .Until Dynamo 3.xx is released, when the fun starts again - but by that stage, Autodesk should be handling the issue for us!

Stop Press - Revit 2016

I have just heard some news that Autodesk subscription licences on networks will stop supporting Revit 2016 within the next month - ie. Revit 2016 will stop working on floating licences, even if you do not upgrade to Revit 2020.  This needs to be confirmed, but if it is true, then Dynamo support on Revit 2016 becomes immaterial!

Saturday 13 April 2019

Revit Conceptual Massing Environment - Index

Over the years I have struggled with the Conceptual Massing Environment (CME) in Revit.  It is not easy to use, and is not at all well integrated with the rest of Revit.  However, I have learnt a huge amount about how to get it to do what you want (or not!).  I have tried to document some of the tips and tricks on this blog and during various conference presentations that I have given at RTC & BILT .

Here is a summary / index of all the relevant posts on this blog:

Conceptual Massing Environment

Rival Revit Environments - Traditional vs Conceptual Massing Environment (CME)


Creating Traditional Forms using Conceptual Massing

Part 1 - Extrusion 
             Extrusion Offset Properties
Part 2 - Blend
Part 3 - Revolve
Part 4 - Sweep
Part 5 - Swept Blend
Part 6 - Loft
Part 7 - Hybrid Swept Blend / Loft

Revit Nurby Forms at BILTANZ

Adaptive Components

Adaptive Components

Adaptive components are a subset of the Conceptual Massing Environment:


Repeaters are a kind of array, in the CME world . . .

Modelling Santiago Calatrava's Gare do Oriente (Lisbon) using Repeaters:
Step 5  Assembling the Array of Structural Columns

Revit Ideas - Vote to Improve the Conceptual Massing Environment in Revit:

Some of the problems could be alleviated by the following capabilities - please vote for them on the Autodesk Revit Ideas wish-list if you agree:

Monday 1 April 2019

Stepped Steps in Revit Stairs

I had a question recently about how to create a Revit stair that is stepped in plan?  It is actually not that hard to do but the method is not so intuitive - so here are some instructions:

Tapered Stair

For the record, we'll start with a tapered stair, to get the methodology - as that is very easy:
  • Create a stair with a straight run
  • Select the run (in stair edit mode)
  •  Convert the run to a sketch 
  • Select the run and 'Edit Sketch'
  • Adjust the angle of one or both sides
  • No need to trim the riser lines (providing the boundary lines up with the end risers
  • Finish the sketch and the stair

Stepped Stair

Follow a similar process as the tapered stair to start with:

  • Create a stair with a straight run
  • Select the run (in stair edit mode)
  • Convert the run to a sketch - this stage is not reversible, so you need to be sure about it
  • Select the run and 'Edit Sketch'
  • The sides and back of each step need to be drawn as 'Boundary Lines', which show green in the sketch mode [Refer to Poor Man's Array for a tip on how to do this]
  • As per the tapered stair, the riser lines do not need to extend out to the boundary lines - this makes it easier to sketch and to modify later
  • Finish the sketch and the stair

You may get some interesting results with the railings, but that can be dealt with in the next blog post . . . . Stepped Handrails in Revit