Revit Stair Wall Joins in Section

Following on from an earlier post about joining stairs and floors, I just wanted to clarify what happens when you try to join Stairs and Walls in section . . . .

We saw previously that Revit does have some limited capability to join stairs and floors at the base of a stair - but it has many limitations.

Joining a Wall and a Floor

All good Revit users would know that if a floor and a wall are of the same material, and they have coincident or overlapping edges, they can be "joined" in the model.  This is not just a graphic tool that is done per view - it affects the model in potentially all views, including material quantity schedules.  If an overlapping wall and floor are joined, the volume of material that was previously counted twice is corrected after the join so it is counted once.

Join Geometry

Select floor and wall to join

Floor and wall are joined

Providing that the elements are of the same material, the line between the floor and wall disappears.  In this example, the 'Level' line is revealed, as it happens to align with the top of the floor.

Joining a Wall and a Stair Landing

 

Try the same thing with a wall and a stair landing . . .

What happens?  Absolutely nothing.  After selecting the wall, Revit will not even highlight the stair landing (or vice versa if you select the landing first).

Well, that is just plain ridiculous!  You might argue that the wall and landing would be cast separately on site, so there should always be a joint line between them - but the graphic convention is to not show a line, or at least show a thinner line between them in section.

 

What to Do?

There is no good workaround to this problem - each method is clunky and not robust.

Linework Tool

Linework Tool

If you try the linework took, you immediately discover that it will not do the job for you, as it affects the whole wall.

That isn't very helpful, as you only want a small segment of the wall edge line to be invisible (or thin line).

Another strange Revit quirk with the linework tool is that when you select a line in elevation (or projection in plan) it gives you blue dots at each end , which can be dragged so that only part of the line has its style overridden.  That is a very useful capability - but infuriatingly, it does not work on cut lines.

Yet another quirk is that the underside of a run is treated as one line when cut (section), but in elevation, each step is a separate line segment.  Why, or why?

Filled Region

Filled Region

A common method of hiding a multitude-of-sins in Revit is to use Filled Regions.  These have pros and cons:

• They are quick and easy to understand for most users

• Their edge lines can be of different styles, including "invisible" as part of the sketch - so they hide model lines underneath 

• They will merge with underlying element hatching , providing the material hatch style matches the filled region hatching

• They are view-based, so any patching up on one view will not show on other views

• Line edges/junctions can be messy when viewd close-up

• If the model is changed, the filled region will not change with it (unless you constrain the sketch lines, which is not generally advisable - as your model very quickly becomes over-constrained and unworkable)
  

Cut Profile

Cut Profile (View Menu)

You could try the 'Cut Profile' command - this allows you to modify how an element looks in a particular view.  Once initiated, it takes you into sketch mode - so you can draw a shape to add to an element (or cut from it).

The end result is not very promising in this situation

• The added shape does not obscure the wall line in the way that a filled region does
• The sketch lines cannot have a line style (unlike Filled Regions)
  

The worst thing about this idea is that the Linework tool does not work at all on cut-profile shapes - thus making this tool almost useless!

Conclusion

Sadly there is no clever workaround.  The conclusion is that it is not worth fighting Revit on this one - just accept the joint line between wall and landing.  In many cases it is not an issue, but when the stair and wall are both cast in place concrete, it is very annoying.

Weird Railing Stuff - part 16 - Rail Hand Clearance Property

Following on from my previous post about Railing Offsets, here is some more detail about the ludicrously inconsistent UI for Handrails and Top Rail offsets in the 'New-style' railings.

Handrail Offsets

Handrails can only be moved laterally within the Handrail Type Properties (not in the railing properties).  This is controlled by a property called 'Hand Clearance'

The Hand Clearance property dictates how far the inside face of the Handrail is offset from the 'Notional Railing Centreline', which is not necessarily where the wall or other railing elements are*.

• The Handrail family has a ‘Hand Clearance’ property, and projection property (see below)
• In trying to use a real-world term, Autodesk have muddied the waters and made it totally confusing to work with.  This property is only logical with certain types of railings:
• one example might be a wall-mounted handrail that has no other linear elements; and even then it only works when the Railing 'Offset from Path' property is set to zero.
• If the railing has balusters and posts, with a Handrail mounted on those, the ‘Hand Clearance’ property does not take account of the baluster/post width, so you'd need to add in half that width yourself.

Once the Hand Clearance property is set in the Handrail family, you have to go back to the Railing family to see the effect it has on the whole railing, where the calculated Lateral Offset is displayed (not shown in the Handrail properties).

The Lateral Offsets are calculated by the system, depending on the Handrail type properties.  Typically this should be:

• Hand Clearance + (Profile Width / 2)    - in this case  40 + 30/2 = 55mm.  
• The Lateral Offset represents the centreline of the Handrail relative to the notional centreline of the whole railing (which is itself moved around by the 'Offset from Path' property).
• If you want a centred Handrail, you need to make its hand clearance property minus half the profile width

Projection Property

• There is another calculated property that is displayed here: 
  'Projection', which is calculated as (Hand Clearance + Profile Width)
  It is again greyed out, and updates immediately after any changes to the profile width or Hand Clearance.
• I cannot see the logic of having this property displayed here, while the Lateral Offset is not.

Changing Properties

The knock on effects of any changes you make is again, a little confusing:

• If you change the profile type, and hence its width then the 'Hand Clearance' is likely to change.  What Revit is trying to do is maintain the 'Lateral Offset' value, and hence the centreline location of the Handrail.
• This may be logical to the software programmers, but not to designers, who would want to maintain the Hand Clearance when the profile width changes.  
• The end result is that you need to pay careful attention, and manually change the Hand Clearance yourself after every profile change.

Once you have made any changes to the Handrail Type properties, then click OK, it returns to the Railing Type properties (if that is where you started from).  There is a display bug here:

• The Lateral Offset does not appear to be recalculated (although it is).
• To cause a display refresh, you need to change the value of the 'Position' to something else, and then back again.
• Alternatively you could close the Type properties and reopen.

Wall-Mounted Handrails

In the case of Wall-Mounted Handrails, where there are no Top Rails or Balusters, the settings need to be somewhat different - and this is about the only situation where the term 'Hand Clearance' makes any sense.

The Railing Instance property 'Offset from Path' needs to be set to zero.  It is very frustrating that this is not a Type property, or at least have a default value stored within the Type properties - as you need to remember to set it to zero every single time you place a railing of this type.

The Handrail Type properties should be set with the actual Hand Clearance that you want - say 40 or 50mm.

Make sure that you choose the correct profile size first, as Revit will alter the Hand Clearance if you change the profile.

The Railing Lateral Offset property will be set automatically.

Top Rail Offsets

• The Top Rail family also has a ‘Hand Clearance’ property, and projection property.
• This is confusing - the Top Rail is meant to be there to support other railing elements, although it may double as a handrail. Whether it serves as a handrail or not, it would typically be centred with balusters etc on the 'Notional Railing Centreline', which is what the Hand Clearance value is measured from. 
• Just to make it doubly confusing, the Top Rail offset is inconsistent with Handrail offsets:  a positive Hand Clearance value moves the Top Rail outside the stair in plan (Handrail moves inside stair).
• Although the calculation for Lateral Offset is the same, it moves the opposite way:
• (Hand Clearance + Profile Width / 2) - in this case  -25 + 50/2 = 0mm
• If you want a centred Top Rail, you need to make its Hand Clearance property minus half the profile width of the Top Rail.

If you set the Hand Clearance to zero, you would get a Top Rail offset by half its width from all the balusters (unless they also had offsets . . .)

Here is  more information on the inconsistency between Top Rail and Handrail Terminology

Creating Swept Blends in Revit Mass - CME Part 5

Part 5 of my series on  comparing the five traditional form creation tools with equivalent techniques in the Revit Conceptual Massing Environment.
Previously we analysed the creation of extrusion forms, Blends, Revolves, and Sweeps in the CME.  Next up is Swept Blends:

Part 5:  Swept Blends

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 . . .

Youtube

For more info on this, view the Youtube video:
Create a swept blend in Revit CME

Creating Sweeps in Revit Mass - CME Part 4

Part 4 of my series on  comparing the five traditional form creation tools with equivalent techniques in the Revit Conceptual Massing Environment.
Previously we analysed the creation of extrusion forms, Blends and Revolves in the CME.  Now  we sweep on to the next form:

Part 4:  Sweeps

 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.

Youtube

Youtube links for those who don't like reading:   Create a sweep in CME