Elevation Depth Cueing in Revit 2017

This is a new feature in Revit 2017, which has long been on many architectural user's wishlist.  OK, lets do some testing and see if we are ready to take it off the wishlist yet?. . . . .

• First I set up a series of walls that are stepped in plan, with a few windows in the walls.

• Then created an elevation view looking at the walls and windows

• In order to examine what is going on with depth cueing, I needed to artificially bump up the line weights of the elevation - in Object Styles:

• Oh, if you are one of those people that likes to read manuals before trying something out, there are some interesting notes in the Autodesk Help files:

Autodesk Help:  

Depth cueing...

• applies to model elements, and graphic display effects, such as shadows and sketchy lines.
• does not apply to annotation elements, line weight, linework, background image, or background color.

After applying depth cueing to a view, you can do the following:

• Export the view to an image file.
• Print the view (raster processing only).
• Add the view to a sheet.

Alarm bells

Any alarm bells ringing yet?  Does not apply to Lineweight or linework;  Raster processing only.
So, if you are the sort of person who likes to use lineweights  to give your drawings depth and readability, perhaps you'd better stop reading now?  Or maybe go and have a little cry?
[Edit] Or maybe you need to rethink how you expect it to work?

Here's How it Works

First go to 'Graphic Display Options' and you'll see a new item called 'Depth Cueing'

Expand it and you'll see some sliders.  By default it will be off, so you need to tick the checkbox.

Unlike the Sketchy Lines feature, you will get an instant result after clicking Apply, without having to adjust the sliders.  Notice how the walls furthest away become lighter and lighter - which is the desired effect, you might think.  But look closer and you'll see that the lines are not getting thinner - just lighter.  This shows up quite well in the image below because I have bumped up the line weight.

The effect is more subtle if you have thin lines and no wall hatching (closer to a typical elevation)

If you adjust the 'Fade Limit %' (lower) slider, the degree of fade is reduced

50% Fade

If you put it up to 100%, you get no fade at all - effectively turning off Depth Cueing:

100% Dark (No Fade)

Not Fade Away

The top slider 'Fade Start/End Location' is actually well described in the Autodesk Help notes - to my astonishment, I found not only an image but a meaningful description that told me how it works, and what it does, rather than the usual one-liner telling me that the feature exists.  Gold Star to whoever wrote that help page.  So I will not go into any detail on how to use it here.

Autodesk Help - graphic explaining Depth Cueing Fade Start/End Location

One of things it states is:
"at Fade Limit 0%, elements that are farthest away could be invisible. In most cases, you want to set a percent greater than 0 to ensure that elements can be seen and printed, if desired."

If you have the Fade Limit at zero (default setting), and start adjusting the 'End Location' (right-hand side of top slider) - sure enough, things start disappearing.

End Location 75%, Fade Limit 0%

Add this to the list of reasons why things are not displayed in Revit!  The list is well over 30 possible reasons by now.  It begs the question, Why did they make the default Fade Limit 0% instead of something safer like 10%, say?

Graphic Display Effects

The help notes state that Depth Cueing works with graphics display effects like shadows.  Yes, it seems to work

I tried enabling the Silhouette setting, and this is where it started getting weird

As I had the wall lines set to a very heavy lineweight, I tried a thinner silhouette, which is the wrong way around from normal - but it showed a couple of glitches:

• Strange dots at the corners of windows - I guess they might be wall edge lines seen end-on where the silhouette has not been applied?  A bug, I guess.
• The actual wall edges are showing a thin line (the silhouette) in front of the greyed out depth cue line, which is still shown at full line width behind it.  The silhouette line is somewhat greyed out but not as much as the depth cue line.
• But why does Revit consider wall opening edges to be silhouettes anyway?  They are not as significant as the actual wall outlines - I would normally want them to remain unaffected by the silhouette feature.

The first two issues would not show up if you reversed the line weights so that Silhouettes are thicker than normal elevation line weights.  However, the window opening lines are still treated as silhouettes.  To solve this you might try the next tool in your arsenal:

Linework Tool

As the help file states, Linework is not affected by Depth Cueing.  'Tis a pity!  And not pretty!

Sliding View Templates

The help files state that you can include Depth Cueing in view templates for similar elevations and sections.  I have not tested this but my gut feeling tells me that the use of the sliders is a very hands-on operation to be done while looking at each elevation and playing around with the settings until it looks right.  I'd be surprised if Depth Cueing and view templates will be good playmates.

One of the issues with standardising these sorts of settings is that outcome depends very much on the view depth and the distance of the cut line from the actual walls (or other elements) - both of which could vary tremendously between different elevations controlled by the same view template.  If you change the 'Far Clip Offset' value in a section of elevation, it can have a radical effect on the Depth Cueing - transforming the look of the view, which means it could be hard to maintain a consistent look and feel for elevations on a project.

[Edit]

Shaded Views

I just realised that I have been unfair in not showing how effective Depth Cueing is when used on shaded or realistic views in Revit.  Obviously line weights are less relevant in this kind of view.

And it works well when you include entourage or landscape families

 And also works with RPC content in realistic views

I should point out that Depth Cueing is not available for 3D or perspective views;  Nor is it available for plan views, which means that we still have to rely on View range 'View Depth' settings and 'Beyond' linestyles to control that.

[Edit again]

Angled & Curved Walls

Click here to read more about angled and curved surfaces in elevation.  It seems that there may be good reasons for Autodesk to choose this method of conveying distance in elevation rather than diminishing line thicknesses - namely how it handles curved and angled walls, which would be very tricky with varying line weights.

Angled wall with depth cueing - works well

Conclusion

You will have to draw your own conclusions as to whether this new feature is going to work for you - I couldn't possibly comment!  I think this may be yet another example of needing to wait until the various shortcomings are fixed in the next version or two before we can take it off the wishlist.

This new feature adds to the growing list of  situations where the control of line weights and printed outcome is hard-coded into Revit, and we cannot do much about it.  Refer to Weird Stuff with Line Weights  and Hatching Pattern Line Weights.

Link: Other New features in Revit 2017

Installing Revit 2017

I have just downloaded and installed Revit 2017 - so I thought other people might like to know some of what is different to previous years, as there appear to be quite a few changes.
For a different experience, refer to  install v2017 from physical media (DVD)

• Firstly, I installed just Revit 2017 (not Building Design Suite).  In previous years it was called Revit Architecture, but now they have come full circle and it is just called Revit again.  This means I have full(?) access to Structure and MEP commands, which may or may not be useful.  It used to be the case that Revit Structure was much better at joining beams than Revit Architecture - so now I can take advantage of that.  I guess this is a good thing, except for the possibility of bloatware (see later).
• In previous years I ordered a physical copy of the media because I found it much more convenient to install from - particularly when you need to reinstall after a hardware failure or upgrading your computer.  This year Autodesk have had the temerity to start charging for this service, despite the fact that we pay a substantial annual subscription. In the email I received a few months back, their rational  was that most people prefer to download software these days - well, there is nothing to stop those downloaders from just not going to the hassle of ordering the physical media.  I would like the choice, particularly as I had already paid for the privilege before they told me.In fact I tried to order a copy just now, and not only is it very carefully hidden away on the website, but it just plain did not work - the website seems to be broken.
  I am wondering if this so called 'nominal' charge to order media is a desperate money-raising measure, or part of a cunning scheme to force everyone to download and install while being connected online (signed in), so that Autodesk can take more control of the process?
  [Edit:  I have since managed to order a physical copy, and done a second installation from this - the experience was dramatically better than the download install, even though I had to pay again for the software that I had already paid for]

• So I ended up downloading - which is a slow process in Australia, partly due to our slower broadband networks (compared to the USA), and possibly we do not have an Autodesk download server hosted in Australia (?).  A lot of other countries would find it considerably slower than here.  The whole download/install took about 5 hours.
• I am not sure when this changed, but now Autodesk have adopted the same horrible system as other vendors of just allowing you to downlad a small setup exe file, then running it so that the software install/download is all wrapped up in one process.  I much prefer being able to download the whole install file then running the install from the C drive, as it gives us more control about when and how it happens.
• As I was signed in to Autodesk, I guess it knew my language and location, as I do not recall being asked for that during the install?  It also did not give me many other options, and it ended up installing some strange bloatware like:
  - MEP Fabrication Imperial Content
  - MEP Fabrication Metric Content [Edit: it may be possible that I missed seeing the checkboxes to avoid installing these]
  I personally don't want either, but I guess MEP engineers would want just one, but very seldom both.  Luckily they seem to be separate programs that appear in my uninstall list.

Firewall

During the install process I had two problems where my anti-virus program took exception to something being installed, and would not allow them - so I skipped them:

• IDP.ALEXA.51
  My anti-virus program said this:  "IDP ALEXA is a potential threat. Threats, when malicious, can be used to interfere with the normal operation of a computer, gather personal information or allow a hacker to access the device remotely without the user's consent.  This kind of software usually arrives in the form of an unwanted download from a malicious website or as code illegally injected into a legitimate website without the webmaster's knowledge."
  Of course it is just being cautious, but I don't like to install anything like that.  We will see if Revit runs ok without it!
• DXSETUP.exe
  Even though I told the AV program to accept this one, it refused.  Then the whole install/download hung for quite a while until I cancelled and restarted.  Luckily it moved on to the next thing.

Installed programs

The final list of installed programs looks like this:

• 'Autodesk Desktop App' is a replacement for 'Autodesk Application Manager'.   I do not like having the application manager running as it prompts for upgrades at inopportune times, particularly for every user in the organisation where upgrades should normally be managed by the IT or BIM manager.
• I believe that Akamai Netsession Interface is part of that deal?  It is giving an error on startup - so I intend to uninstall both of those in due course. 

Autodesk License Service - 270Mb !! looks like more bloatware, but I suspect I won't be able to get away with uninstalling that one.

More Bloatware (and missing family templates)

There seems to be a lot of extra stuff installed this year - here is some more, related to different language versions.  I suspect that 'Revit' comes in a multi-language install whereas Building Design Suite allows you to choose the language (as did Revit Architecture in previous years).  The extra language family templates give me 270Mb of installed stuff that I don't need.

It is curious that each language has a different number of templates.  English Imperial has 82 rft files, while English Metric only has 73.  Some other languages had even fewer.  I noticed that the following seem to be missing from the Metric templates (for Australia at any rate):

• Casework wall-based
• Casework
• Door
• Door - curtain wall
• Entourage
• Generic Model (non-hosted)
• Plumbing Fixture
• Profile Mullion
• 3 extra imperial rebar templates added in for good measure

So none of those are particularly useful to architects (not true!).  Perhaps I'll use the Chinese or Czech templates for all my casework and doors?

[Edit]
In the Public Folders is a new Autodesk folder, with MEP fabrication 'stuff'

• I just don't want this stuff installed at all.  
• And even if I did want it, I would want it in the ProgramData folder along with the rest of the content.
• And if it went to the right location I would want either metric or Imperial, not both!

Foreign Project Templates

Oh, and here is another 40Mb of stuff I don't want (unless I get a project in Europe or Asia) - in a new 'Generic' folder under Project Templates

Temp Install Files

My last task will be to make a backup of the install files so i don't have to download them again.  And that looks different too.  There seem to be two different folders, with lots more language packs that I don't need.

• Revit_2017_G1.. .. . .    seems to be the setup files
• WI                                  seems to be the 4.7Gb install files

[Edit] It would have been nice if they were all contained in one folder, or else the 'WI' folder had '2017' in its name so that I can identify it later.
[Edit again:  I later tried to reuse these downloaded install files on another computer, and they did not work]

Conclusion

This process  was not much better or worse than previous years - just different problems!  There seems to be a lot more bloatware now that Architecture/MEP/Structure have been bundled together again.  There also seems to be a lot of sloppy work with things like languages and templates.  I have not looked at the libraries yet - I hope they are complete.  I will not be putting v2017 into production work for a while yet - I only installed it so I can use it for preparing my RTC presentations, which should be a good test-bed, and allow me to try out the new features.
[Edit:  I have since managed to order a physical copy, and done a second installation from that - the experience was dramatically better than the download install, even though I had to pay again for the software that I had already paid for.  Refer to  install v2017 from physical media (DVD)]

What's New in Revit 2017

As Steve Stafford has compiled a comprehensive list of new Revit 2017 features over on OpEd, I will not write a list here.  Instead I will comment on a few features - especially since the Autodesk Help files are so sparse on detail.  We all need to know the benefits and shortcomings of each new feature.

I have previously commented on v2016 R2 features (in this link), which are obviously now included in v2017.

New in Revit 2017 (selected features)

Global Parameters

My initial description of Global Parameters as introduced in v2016 R2  is only relevant if you are still using v2016R2.
For more details on Global Parameters in v2017 click here

Improvements in v2017 are more significant than I first thought - they include:

• Type Parameters can now be linked to Global Parameters (GPs)
• Assign global parameters to groups within the list in the GP dialog box
• Reorder GPs in the list
• Filter a schedule by parameters that have GP associations - this should be invaluable for tracking down all those associations that are making unexpected changes to your model!
• Show Label in View - hopefully useful, but that 'Cannot find view. . .' message is a worry when looking for other warnings and issues, so I don't know how useful it will actually be?
• Transfer GPs between projects

All of these are very welcome additions to this exciting new feature.  However, we are still missing the ability to associate GPs directly to many system properties, although this has improved in v2017.

More on this . . . . Global Parameters in v2017 click here

Schedule Templates

Schedule templates now include parameters for Fields, Filters, Sorting/Grouping and formatting - previously it was only the Appearance that could be included in a schedule template.  This sounds wonderful, but in my opinion it is very dangerous in the way it has been implemented:
If you apply a schedule template to an existing schedule, it will entirely replace all your fields, filters, sorting, formatting.  This means that if you had all sorts of complex calculation fields in the original schedule, they will be destroyed and lost forever!  It is all or nothing - you cannot just include some things in the template without the others (eg. filters & formatting only, without fields).  I understand that it would be tricky to separate out what is contained in each template as the fields are interrelated - ie. it has to exist in the field list in order to be formatted or used in a filter.  However, I think we should have had a cleverer implementation that allowed us more flexibility and safer control.
Unless the final rollout of v2017 has changed since I last tested, there is no ability to "overwrite or append" to a schedule where fields already exist - it just replaces without so much as a 'by your leave'.  Mark my words:  There will be tears before bedtime!

So, a word of caution:  plan how you use this very, very carefully - set up some complex scheduling and save it as a template first so you don't lose the calculations!

Combine Schedule Fields

Steve Stafford described this very well in his blog over on OpEd, so I won't replicate the description.  While this is a great step in the right direction, it will only allow you to combine or 'concatenate' parameters in the actual schedule output.  This means that combined parameters are not visible in the element properties dialog, nor can you tag them, nor will they be exported (unless you export just the schedule).  So if you need to actually populate element properties with combined parameters, you will still need to use Dynamo, API or a third party add-in.

Calculations in Annotation Tags

Another very welcome addition to tagging capabilities, but again this comes with some serious limitations:   The calculations are defined in the tag in family editor - this means that you have to replicate identical calculations in a schedule if you want to see the same results in both schedules and tags.  That is asking for user errors.  In addition, when working in the tag, you will not be able to access any Project Parameters, Schedule Parameters, and some System Parameters only visible in projects (such as offset from Level) - depending on the category, some system parameters are available in tags, some are not.  eg. Base Offset for wall is not available; but Sill Height is available for windows.  This means that we will need to use more Shared Parameters instead of non-shared Project Parameters, although that won't solve the issue of System parameters - of course shared parameters can't be used in all situations anyway.

This is a good first step to fixing a problem with tags, but it needs to go much further by allowing us to embed the calculations back into the actual elements so they only need to be done once then be available everywhere (properties, schedule, tag, export).

Tangency Locks

[Edit] When editing a sketch in the family editor, we can now 'lock' the join between a line and an arc to maintain it as a tangent join.  I am very happy about this new feature - I have long struggled to control arcs in Revit.  Most of the time, in simple situations it works well.

In this example, the end of one line is adjusted so the line changes angle - and the arc is extended to maintain the tangency.

However, it needs to be used with a little caution until we all understand exactly how it works and what it does to overall sketches.  I tested the simple sketch above a little more by adding parameters to the radii, and it had some unexpected consequences.  Previously, if you moved/rotated a line that had a tangent arc at its end, it often just broke the tangency.  Now it can possibly have a knock-on effect all along the sketch:  It can completely move lines on the sketch way along the chain beyond the tancency lock.

 When the end of the right hand line is moved in, the radii change, and the left hand line moves in

When the end of the right hand line is moved out, the radii increase, and the left hand line moves left

Move the end of the line a bit further and the sketch goes crazy:

As the tangencies cannot be broken, something else has to give!  To prevent this sort of behaviour, every line would have to be dimensioned/constrained in location and angle.

This means that we will need to put more thought into controlling the whole sketch - not necessarily a bad thing, but it could cause problems if you add tangency locks to old sketches.  We have often been lazy in the past because we could get away without adding dimensions or constraints to many lines in a sketch - Revit would do the work for us with implied constraints (lines generally stayed parallel even if the moved, and they locked themselves to nearby reference planes).

More on this - click here, as it requires a careful analysis . . . .

Elevation Depth Cueing

I have done some testing of this new feature - read about Depth Cueing here for more detail.  Read about depth cueing on angled/curved walls here.
It seems that in order to display receding distance in Elevation and Section views in Revit, Autodesk have chosen the easy path of making lines lighter the further they are away, rather than allowing control of line weights, which is the old conventional drafting method.  It certainly does achieve an effect of 'distance' even if it has some limitations (like not working with line weights or anything worked over using the Linework tool).  You may not like the method it uses or the simple controls which are easy to use but will probably make consistent output very hard to achieve.  You may also not like printing all your elevations using the raster driver, although I hear that it is less of an issue than it used to be.

Installing Revit 2017

Installing Revit 2017 using a download is a whole new adventure (not a pleasant one)
Read about download/installation here - not much fun at all
Read about installing from DVD media here - a much pleasanter experience

New Revit Icon

I like the new Revit icon - it looks less like folded paper, and more like a carved sculpture that you could not possibly make using the massing tool, however hard you try.  I like to have a different icon each release so that you can easily tell which version is showing up in your windows taskbar - especially if you have multiple versions open.

Conclusion

This post is not meant to sound negative - I am just warning you about issues with new features that sound too good to be true!  They all have value but need to be treated with care.

Is Revit 2017 good value for all that subscription money you payout?  You might not think so, but I could not possibly comment.  For an architect there is not a huge amount to be excited about - many new features are relevant to other disciplines or might be of more benefit to others downstream.

There are no big standout features in v2017 that we must have now, so I will be a little cautious about rushing into the upgrade, particularly as there are a lot of goodies to be had in v2016 R2 already, without the pain of another file format change.  When you add the list of v2017 features to those in v2016 R2, it is a reasonable number of small additions and tweaks - but there are so many, many more to address, let alone some of the underlying structural changes that need to happen in order for us to be able to use Revit efficiently.

Weird stuff with Revit Line Weights

Following on from my previous post about line weights for material patterns, I have found some more weird things about Revit line weights that I never knew before:

1.  Pattern Line Weights

As Frank Giorlando rightly pointed out in a comment on the previous post:  Ceiling surface patterns use Line Weight 2.  So, if you want to control those independently, you should start your regular line weights from #3.
Thanks for that tip, Frank.

It would not surprise me if there are other categories that use different line weights again.

2.  Apply Button

The "Apply" button on the Line Weights dialog box does not appear to work - so if you start changing settings for different scales and want to check what happens (with hatching lines for example), you have to click OK to close the dialog box to see the effect.  I wasted a bit of time making changes that did not seem to be having any effect before I realised.  (as of Revit v2016 R2)

3.  Grid Line Weights

In testing the previous bug, I discovered some more weird settings:
Gridlines have all sorts of hidden away weight controls -
Unlike most elements, the actual grid line weight numbers are controlled from the grid Type properties (not from the Object Styles settings).  However, the Grid Heads have a master control in Object Styles where you might expect the gridlines to also be controlled

And something else I never knew:  The type properties for grid lines allow you to set different line weights, colours and styles for the centre and end segments - by choosing 'Custom' Center Segment..

Why would anyone want this?  I guess someone out there needs it and the programmers thought it would be useful.  Personally I would have been happy to see the weight set in Object Styles, with Visibility Graphics overrides if you need them - like most other categories.  This just seems like an unnecessary complication and inconsistency.

[Edit: Steve Stafford has previously blogged about how and when to use the Center Segment setting in this link.  I can see that you might well want to have a gap in the grid, but I still can't imagine why anyone would want a different line weight - just to make their drawings look ugly?  This also highlights the radically different way to control breaks in the middle of gridlines vs breaks in the middle of section lines - oh, I wish we had more consistency in UI and methodology in Revit]

4.  Dimension Tick Line Weights

Another category where the line weights are controlled in the Type Properties is Dimension lines.  The line itself and the dimension 'Tick Mark' have independent weight settings (at least both appear to be in the same place, unlike grids and grid heads).

But when you go to the arrowheads dialog box and check the settings for the Tick Mark, there is another weight control called "Heavy End Pen Weight".  Now someone is showing their age by using the term "Pen" in there!  Most of the time it is greyed out and has no effect, but if you cycle between the different Arrowhead Types, each one has a different value.  Why?

Well, if you change the Arrow Style to 'Heavy End Tick Mark' it enables that setting and you can change the number.  If you change the Arrow Style back to Diagonal or Arrow, it greys out the number but remembers it - I guess it does nothing.  I decided that I do not want to know what a Heavy End Tick Mark is nor why it needs its own special setting that causes confusion to the other arrow styles - it is a 'rabbit-hole' I don't want to go down any further!

Note the mix and match of imperial and metric units that came straight out of the v2016 metric sample file.  Sloppy work by someone there!

[Edit: Steve Stafford has blogged previously about when you might use Heavy End Tick Marks in this link]

Really Weird:  Line weights in Perspective Views

Revit Hatching Pattern Line-Weights

Following on from my post about hatching patterns on stairs, I thought I would describe a strange Revit phenomenon that I noticed a few years back. . . .

There are two main types of hatching patterns in Revit:

• Hatching patterns applied to the surface of a material, or as a cut pattern
• Filled Regions - 2D annotation patches

I intend to discuss the former - in particular material surface patterns.

As any good Revit implementer should know, most Revit material hatching patterns are displayed and printed using the Revit line-weight number 1.  [Edit. Ceiling surface patterns use line weight 2]
This number is then converted to a line thickness according to the scale of the view, on a matrix chart accessed from the 'Additional settings' icon on the manage tab of the ribbon.

This matrix is stored per project, and is something that should be set up in the company project template, and then seldom changed.  Unfortunately many new users are not aware that material hatching lines use line weight 1, so they often assign that as their general use thinnest line drawing number.  Most experienced users would recommend reserving weight 1 for hatching, then start the rest of the element line weights from 2 onward (2 = 0.1mm, 3 = 0.18mm, 4 = 0.25mm, 5 = 0.35mm etc).  [Edit. or start from 3, to avoid ceiling hatching patterns in 2].  Once you have set up all your family templates, and libraries it is not easy to change them all a year later.  Sadly the default templates and Autodesk libraries are almost all set up to default most things to weight 1 as the thinnest line weight, which propagates this awkward setup.

Incidentally, if I use the term 'Pen 1' instead of Weight 1, it gives away the fact that I once used pen plotters in the dim, distant past (or even Rotring pens!).

Let's assume that you have set up your library and templates to reserve weight 1 for hatching, it gives you more freedom to play around with pattern line-weights without affecting anything else in the drawings.  But you need to know some mysterious things about how you can control hatching display - or in fact that you have very little control!  The reason for this is that there are various limitations and some hard-coded behaviours within Revit.

Material Surface Patterns - Law of Diminishing Returns

When you apply a surface or cut pattern to a material, you do not get any option to set the line weight - you can only control the pattern and colour.

Object styles do not give you the opportunity to control material pattern line weights;  nor do Visibility Graphics pattern overrides, which can be changed per category:

Or they can be overriden by element, where you can change the weight of projection or cut lines but not hatching patterns:

Notice the colour of the hatching lines at different scales in the screen snapshots below - I have chosen the 'colour purple' to make it easier to distinguish.  At scales from 1:1 through to 1:50 they would all look the same (I only show 1:20 onward), but after that the lines get progressively lighter at each scale change.  This is hard-coded into the software - not something that we appear to have any control over.

1:20 material hatching

1:50 material hatching

1:100 material hatching

1:200 material hatching

1:500 material hatching

1:1000 material hatching

1:2000 material hatching

1:5000 material hatching

You might notice that the line thicknesses above are the same from 1:20 up to 1:1000, which would not necessarily be the case in a real Revit project.  I artificially bumped up the line thicknesses at the smaller scale, to compensate for the screen scale display of the lines.  I ran out of 'thinness' for 1:2000 and 1:5000 as the thinnest that Revit lets you put in is 0.025mm.  However, it is unlikely that your plotter will be able to get lines that thin anyway.

Artificial settings to get consistent screen display - do not use!

At 1:5000 the hatching just stopped displaying - or maybe the lines are so pale we can't see them.  I'm not sure how Revit decides at what scale to give up displaying, as it is not always the same.  It seems to depend on the line thickness, and spacing as well as density of the pattern.

For more weird Revit line weight behaviour click here

What does it all mean?

This is another example of  the software writers deciding what is good for us!  We have no choice or control that I can figure out.  All I can recommend is to reserve weight 1 for material pattern hatching.  It is probably wise to put all filled region hatching in weight 1 too, so that when you apply those nasty little filled region patches in section, they blend together.  Normally I do not approve of that, but when it comes to pads and earth hatching in section it is pretty much unavoidable!

I did wonder about that print settings dialog option 'Replace halftone with thin line':

It does not treat those faded hatch pattern lines as halftone - it only affects them if the whole element or category has been set to halftone.