It still has a number of limitations but at last we can make use of it to some degree. What makes the big difference is the ability to add "Waypoints" anywhere along the path of travel.
You may remember (from my earlier descriptions) that when you place a 'Path of Treavel' by clicking the start and end points, Revit calculates the path for you - and you had little control over that, apart from choosing which elements form obstructions (or not). Hence, in the standard Autodesk sample file, the path calculation was not able to determine that a sofa at a lower level should still be an obstruction:
Path or travel in v2020
In 2020.2, the calculation seems to have been slightly rationalised to give a more sensible path through the corridor to the north, but it still goes over the sofa in the split-level living area.
Path of Travel in 2020.2
Add Waypoints
We now have the ability to add (or remove) 'Waypoints' - this allows us to nudge the path to a more sensible course around the sofa.
If you need to make your path of travel orthogonal (as required in some jurisdictions), it can be done by adding enough waypoints - rather laborious but at least it works.
This is a very welcome addition to this feature. However, it is still taking longer than the Daleks to learn how to manage stairs and changes of level in the building.
There is still no way to control the minimum width of a gap between obstacles (about 430mm or 17")
With the release of Revit 2020.1, we have been given four minor improvements to the new (2020) 'Path of Travel' feature in Revit. Welcome as they are, these improvements do not address any of the fundamental shortcomings of the tool, which seems like a missed opportunity:
Start and End Points of travel paths can be dragged.
Reveal Obstacles toggle.
To and From Room properties have been enabled (these were previously just blank instance properties in 2020).
Two new Dynamo nodes for Travel Paths (presumably new API capabilities allow this?)
Start and End Points
If you select an existing 'Path of Travel' element (which behaves like a polyline detail line) it now displays a blue grip-handle dot at each end.
Select the grip-handle and drag it to a new location - while doing so, Revit displays a moving straight line directly between the cursor and the other end of the path.
Once you let go the grip-handle in its new location, Revit recalculates the path of travel
Associated properties, schedules and tags will also be updated.
This is a very welcome little change to behaviour - if you tried this with the original vesion (2020), it just moved the whole path of travel. However, this is only a small usability enhancement. The fundamental issues it does not deal with include:
Still no ability to choose, change or control where the actual path goes (apart from adding/removing obstacles). In order to do this, we would need to be able to somehow nominate additional points along the path, which it must go through. [Edit. * NB. Revit 2020.2 improves on this]
No ability to make the path orthogonal (in Australia I have never needed that, but comments on my last blog post indicated a requirement for this in North America) [Edit. * NB. Revit 2020.2 improves on this]
No ability to deal with sloping floors, level changes (split level), stairs.
No ability to prevent the path going through a very narrow opening (430mm or 1' 5") - more on this in another blog post.
NB. Given that the default selection colour in Revit is dark blue, and the grip-handles are mid/dark blue, it is pretty hard to even notice this new feature. I would recommend changing your options for selection (and pre-selection) colours to something other than blue.
Incidentally, which *!@*&#$ at Autodesk thought it was a good idea to make the selection and pre-selection colours the same (both dark blue)!
Reveal Obstacles toggle
This is a useful new tool for figuring out why your path of travel is not behaving as expected. Again, this does not address fundamental shortcomings - such as:
What do you need to do when Revit fails to generate (or update) a path at all.
Creating a Swept Blend in the Conceptual Massing Environment. . . .
A swept blend requires two or more profiles, each perpendicular to the path ;
In the traditional Revit environment, a swept blend can only have two profiles;
Unlike a sweep, the path can only consist of one element (line, arc or curve), even if the profiles are closed;
Unlike
a sweep, the profile cannot contain a loop within a loop (to make a
hollow form);
The easiest way to do this is to host the profiles on points
– in the example here, an arc has 3 points that define it, so they can
also be used to host the profiles
The profiles can be model lines, reference lines or loaded 2D profile
components - each method has its own advantages or disadvantages (described below) depending on how you want to modify the form later on, so there is no clear 'best method';
Create Form by selecting the profiles and the path
In this example, the profiles are the same shape, so there is a smooth transition, and you cannot even see the middle profile
NB.
If you had just selected the profiles, Revit would decide its own path, which
may not match the one you created – in which case the form would become a
‘Lofted’ shape
Edit Form
Editing behaviour differs, depending on the original profiles and path:
For
model line profiles, you can use ‘Edit Profile’ – it will prompt you
for which profile to edit, so you may need to put the form into X-Ray
mode to be able to select the middle profile(s) or use wire-frame mode
In sketch mode you can modify the profile, or change it entirely
However, if you don't have the same number and type of segments in each profile, it may result in sharp edges
Try matching the segments in each profile, to make the transitions smooth, without edges
For reference line profiles, the profiles can only be changed in
size/proportion, depending on how much you can manipulate the reference
lines without breaking the profile (but you cannot add segments)
For
loaded component profiles, they can be parametrically controlled (best
method), but you cannot reload a profile with a different configuration
or number of segments
Point Hosting
The Autodesk help files recommend putting the
profile(s) onto points hosted on the path (rather than using the points
that define the path in the example above) – this has several
advantages: it should give more control with moving end points and
rotation
Unlike a sweep, when you create a form, it does not extend along the whole path – only between the first and last profile
If you adjust the path underneath, the form follows it:
If the profiles were model lines, then the lines and host points on the path are ‘consumed’, which means the host points cannot be selected or manipulated, and the model lines have limited controllability (except in edit profile sketch mode).
Dissolve
If the form is dissolved the model lines and points are kind of reinstated but not to exactly their original state:
Circles are split into semi-circles
Points lose their display status
For this reason, you may need to recreate or rehost the profiles after dissolving a form, and reset some properties.
Loft vs Swept Blend
The important thing to note with Swept Blends is that the path is included during the creation of the form, but does not become part of the form itself; when the path is modified, the form changes too.
If the path is not included, the form becomes a 'Loft'.
The inclusion of the path can be extremely useful when it comes to modifying the form - as will be seen later . . .
Creating a Sweep in the Conceptual Massing Environment has a few unexpected rules and exceptions - some of which you can use to your advantage.
First you have to create a path for the sweep, consisting of one or more chained lines, arcs or curves (model or reference) - this is one of the few occasions that you can have multiple element segments to a path in the conceptual massing environment (if not the only one).
Then create a profile that is perpendicular to the element of the sweep that it intersects.
NB. If the profile is open, Revit only allows a single element for the path
You can place the profile on a convenient perpendicular work plane but the easiest and most reliable way to do this is to host a point on the path then host the profile on the point (set the point reference as work plane) - as recommended by Autodesk.
Select the profile and path;
Create form
It should create the sweep
However, it may give a message ‘Unable to create form due to self-intersecting geometry’
The most common reason might be if you have arcs/curves on the path where the radius is too small to make the transition between straight sections on the inside, as in the example below where the middle arc radius is very close to failing – two profiles are almost meeting each other on the inside of the corner
To avoid this problem you could make the path radius larger than required to start with, then reduce it afterwards so that you can see where any problems occur; alternatively, make the profile smaller, then increase it after the form is created - check in X-Ray mode to see where profiles may be close to intersecting.
To edit the path or profile:
If the profile was made from model or reference lines, it can be edited in sketch mode using ‘Edit Profile’ once any part of the form is selected;
The path (model or reference lines), can be edited in sketch mode – in a very limited fashion, eg. changing the radius of an arc; in this case you may need to use the X-Ray mode to be able to see the path to select it.
Hollow Sweep (Nested Profiles)
In the Traditional modelling environment, Revit usually allows you to have nested loops within a profile in order to create a hollow form. The Conceptual Massing Environment is less forgiving - I have only found two situations where it is allowed: One is Revolves and the other is:
Revit does
allow a profile with a loop inside a loop, but only if the profile is made from lines/arcs – not from a loaded family profile;
You could offset/copy the original profile (or draw a new inner loop profile)
Select both profiles and the path elements
Create form
Hopefully it will create a hollow form
It will show joint lines for each segment of the path
If you want to use a loaded family as the profile, It does not allow you to create a hollow form in one command:
You need to create two separate forms, one solid and one void;
In this situation, it is best to keep the path as reference lines, so that they can be used for both forms;
Select the path plus outer profile;
Create the solid form
Make it X-Ray so that you can see and select the path and the inner profile
Select the inner profile and the path
Create Void Form
It should cut the void from the solid automatically
Interestingly the combined form does not show any joint lines (where transitions are tangential) – this is desirable in the project
Joint Lines
Prior to seeing this result, I tried hiding the joint lines in the project by putting them into a subcategory or associating a visibility parameter but that affected the whole form, not just the joint lines.
Making the original profile a reference line does not hide the joint lines either
It looks like we may have to create combined solids just to solve this.
