Slanted Wall Joins in Revit 2021

Following on from my Analysis of Slanted Walls in Revit 2021, and Analysis of Slanted Walls and Rooms in Revit 2021 let us see how it handles slanted wall joins in plan.

Mysterious Behaviour

I have not yet figured out the rule for this, but it seems that slanted walls sometimes join properly in plan and sometimes not . . .

The failure of wall layers to join seems to occur at varying wall angles and different view range cut heights.

At gently slanting angles the problem does not manifest itself:

• At 25 degrees (or less) with a standard wall cut height of 1200mm (or 4 ft for the imperialists), the wall joins ok
  

• Bump the slant angle up to 30 degrees and it fails
• In this example the base offset of the wall is raised 900mm above the Level that it is hosted on - that causes all kinds of issues, but it is not the problem here

• Change the 'View Cut Plane Height' to 1000mm, and it works again - but of course the cut location of the wall changes

• Change the angle to 45 degrees and it breaks again
• It seems that the base height of the wall has no influence on this (providing it is below the cut height).
  

There must be some mysterious formula that combines the cut plane height with the wall slant angle that makes it work or fail!

Of course it should not fail at all - why doesn't it just work as expected?

Talking of "Course", this problem doesn't show up in Coarse views - only Fine and Medium detail levels.

Reveal Obstacles in Path of Travel - Revit 2020.1

Revit 2020.1 Enhancement

If you place a 'Path of Travel' using the new (in Revit 2020) feature, you may encounter a situation like that shown below, where the path appears to go through an object that should be an obstruction - such as the path through sofa example below:

 

In addition to other Revit 2020.1 enhancements to the Path of Travel feature  - Move Start/End Points, we have a new tool that may help you out:

Reveal Obstacles in Path of Travel -

This is useful for figuring out why your path of travel is not behaving as expected. 

• On the Analyze toolbar, click on 'Reveal Obstacles'

• This temporarily changes the view display to show in orange all categories that represent obstacles to the path.

In the example below (Autodesk sample file), some items are not shown orange

 

• The doors are not obstacles because that category is excluded
• Some furniture is not shown in orange (obstacle) because they are below the cut plane for calculation.  The reason is that the model is split level, and the living area is 500mm lower than the rest of the house - refer to Analysis Zone follow up for more detail on Split Levels and calculation heights.
• In the case of the large sofa family, one part of the component shows orange - this is the high back.  This demonstrates that Revit actually analyses the geometry of elements, not just a bounding box for each component - which is a good thing.

As the sofa is much lower than the main floor level, only the back projects up into the analysis zone.

• If the sofa is raised by 200mm (8"), then the sides of the sofa also project into the zone - they become obstacles, and hence turn orange (it may not be immediate - see glitches listed below).

However, the path itself does not change - you have to select it and click on 'Update Path' for that to happen;  then the path will go around the sides of the sofa.

Obstacle Settings

 

If you go the the Route Analysis Settings, you can add or remove obstacles by category - for example add Furniture and Casework categories to the list that are not obstacles

Initially nothing happens, but when you update the path it will no longer avoid those categories.  These will no longer be highlighted in orange by the 'Reveal Obstacles setting

Furniture no longer an obstacle

Casework category no longer an obstacle - path not yet updated

NB. There is some unexpected behaviour that can occur with the 'Reveal Obstacles' feature:

• If you already have 'Reveal Obstacles' mode on when you go into the 'Route Analysis' settings, then change the categories - Reveal Obstacles does not update the categories displayed orange/grey (you need to turn it off then on again for a refresh).
• If Reveal Obstacles mode is on, and you try to select an element:
• Initially it will highlight all of the obstacles as one item;  select it and you get Analysis results Properties (see below for more details)
• if you tab select, it highlights a component, but still considers it part of the analysis result;  Select it and you get Analysis Result listed but without any properties;
• Tab again and it finally selects just the element - you can then change its properties;  However, the Reveal Obstacles highlighting is not updated even when it should be - eg. if the sofa height is changed to 500mm so that the whole sofa becomes an obstacle, the sofa does not turn orange (when it should).

• If you select the whole analysis result, you get shown properties for the Analysis Result.

• It is not immediately clear what these properties are for.
• If you click on the 'Edit..' button (Results Visibility), as you would be tempted to do, you get some more mysterious properties

•  Make the dialog box a fraction wider, and one of the headings shows in full:  'Analysis Display Style' - it has a hidden button to the right of <By View>

• Click on the hidden button to reveal the Display Style dialog

• You can play around with the text and arrowhead settings

 

• And go to the Legend Tab
• Click on 'Show Legend'
• The end result means not much to me, but I'm sure it has a purpose

Arrowheads and legend displayed

•  You can move the legend on the view, if that is what you need

I am guessing that these analysis display settings are for some other kind of analysis, but have been enabled here too?

• I am not going down that rabbit hole today!

 

Conclusion

Sadly, useful as this new feature is, it does not address fundamental shortcomings - such as what you need to do when Revit fails to generate (or update) a path at all.

We need more help to be able to deal with that situation, as the Warning dialog box is not at all helpful!

Gare do Oriente - Nested Revit Repeaters - part 1

In 2013 I presented a paper titled "Fractal Fun with Revit Repeaters and Adaptive Components" at three RTC events in Auckland, Vancouver and at the inaugural European Revit conference in Delft, in the Netherlands.  Part of the presentation involved a live demonstration of how to construct a parametric Revit model of the roof of the Gare do Oriente railway station in Lisbon, designed by Santiago Calatrava.

Gare do Oriente by Santiago Calatrava

Since then I have had a number of people asking me how it was done - it was of course described in step-by-step detail in the RTC handouts.  Those are not so easily accessible now, so I am posting the content here, in stages.  Part 1 involves creating a rig for one of the structural supports of the roof.

I will not show a step-by-step guide here as the process is described in a video tutorial:
here is a youtube link

As a reminder, below is a list of the steps required in the process:

• Start a new Adaptive Component
• Place a point at the origin (X,Y,Z = 0)
• Make it adaptive
• Make its 'Show reference planes' property to 'Always' visible
• Set the workplane as the horizontal reference plane of the adaptive point
• Place another point on top of the adaptive point
• Move it up in the Z direction
• Associate its 'Offset' property to a parameter 'Height' (NB. it will only have an Offset property if it is correctly hosted on the horizontal reference plane of the adaptive point)
• Draw a reference line from the top point down to the adaptive point, making sure 3D snapping is on (Options toolbar)
• Place two more points, both hosted on the reference line
• Make the upper line-hosted point always show reference planes
• Change its Measurement Type to 'Chord Length' or 'Segment Length' (NB. because the host is a straight line, in this case Segment length is the same as chord length, which just means direct distance)

Hosted point Measurement Type

• Associate its 'Chord length' to a parameter called 'Perimeter Drop'
• Change the Measurement Type of the lower hosted point to 'Chord Length' or 'Segment Length'
• Associate its 'Chord length' property to a parameter called 'Valley Drop'
• Flex the parameters to test the rig thus far;  move the adaptive point to check everything else is hosted to it

Circles to host geometry

• Set the workplane as the horizontal reference plane of the top point
• Place a reference circle centred on the point
• Make its temporary radius dimension into an actual dimension
• Associate the radius dimension to a parameter called 'Radius outside'
• Set the workplane as the reference plane of the upper hosted point
• Place a reference circle centred on the point
• Make its temporary radius dimension into an actual dimension
• Associate the radius dimension to a parameter called 'Radius inside'

• Create a formula for 'Radius outside' = Radius inside * 1.4142

Divide Path

• Select the top circle
• Click on the 'Divide Path' icon
• Set the number of points to 8
• Select the lower circle
• Click on the 'Divide Path' icon

• Set the number of points to 8

The basic rig is now complete, ready for adaptive components and repeaters to be hosted on it.  These will be covered in following tutorials.

Step 2  Putting roof panels on top of the rig . . .
Step 3  Creating the structural elements and placing on the rig
Step 4  Adding Struts to the structure

Step 5  Assembling the Array of Structural Columns