Roof Objects vs. Rocket Scientists

[willofmaine]

Possibly against my better judgment, I'm trying to learn how to use the Roof Object and Roof Styles.  It's been an uphill battle... like trying to climb up a 16:12 roof without a rope...

 

So I started from scratch in a blank file with four un-styled walls and an un-styled Roof.  Finally, I was able to (mostly) make sense out of things.  Then I proceeded with a Roof using (a Vectorworks default) Roof Style, and things went downhill from there (yeah, I fell off the roof), as I could not for the life of me control the fascia or soffit.  Ultimately I concluded that if I consider the Bearing Height and the Bearing Inset to be entirely meaningless, and set the Inset to 0" and manually position the roof at the desired height, I could get the Roof and its fascia to work.  The soffit seems to be an entirely lost cause.  See attached file for the progression of my attempts to get the Roof to work.  What am I missing?!?  @Christiaan and @Gadzooks, you guys seem like the rocket scientists of Roofs... maybe you have some answers?  Thanks!!  -Will

04-Roof Object Issues.vwx

[Christiaan]

I'm definitely no rocket scientist of roof objects! Most of our projects have flat roofs so roof objects are one of those things I need to relearn every time I go near them, including by looking over my previous posts on the forum! This is especially the case given that the roof tool is unintuitive and hasn't been modernised. It's the kind of thing you get when programmers design in assumptions without a good knowledge of architecture. In fact your analysis file strikes me as a good basis for an enhancement request.

 

The first thing I usually do when using the Roof tool is to break it down into Roof Faces as soon as practicable. I find roof faces easier to work with. And on a recent project I took that one step further and broken things down further, into separate Roof Face objects (on separate layers) for each of the following elements:

• external finishes (tiles, tile battens, counter battens)
• structure (OSB deck, rafters)
• and where applicable internal finishes (batten + plasterboard).

This provides more intuitive control over each of these elements because there are less variables to worry about and you can focus on the relationship of each element to the walls separately. On the downside you have many more objects to manage. And, of course, Roof Faces don't support fascias and soffits.

 

But I wonder if you might try modelling your roof with two Roof objects (not something I've tried). One for the main structure (rafters) and one for the purlins + sheathing + standing seam. That might provide more intuitive control when it comes to bearing, soffits, fascias, etc. You would add the fascia + soffit to the structural roof object. You might have to experiment whether you add the purlins to the structure or the finishes.

Edited December 14, 2021 by Christiaan

[Tom W.]

Roofs are not my favourite. They are one of those objects that no matter how hard you try + how ingenious you strive to be, you just reach a point where you can’t take things any further + you have to live with something that's unfinished/unsatisfactory. 

 

I looked at the built-in soffit/attic/fascia options at the beginning + immediately decided they weren’t fit for purpose + have modelled them myself ever since. I can’t even remember what the precise issues were, only that the features were of no use whatsoever!

 

The bearing inset, bearing height + datum settings work together to determine the point where the roof rafter bears on the inside edge of the structural component of the wall i.e. the inside edge of the wall plate. So measure back from the front of the wall to the back of the wall plate + this gives you’re your bearing inset. Measure up from the floor level (the 0 level for the floor layer) to the top of the wall plate + this gives you your bearing height. Then ensure that the roof datum is set to the underside of the rafter component.

 

I should say that I always make these settings after the fact: it really isn’t possible as far as I can see to set things up in advance + expect the roof to work. I just create the roof with slightly arbitrary settings to begin with then split the screen + have a section viewport on one side + the roof on the design layer on the other side, and make adjustments to the roof + check their effect in the VP until I have it the way I want it.

 

Setting up the component offsets is another massive palaver but I find I can generally get something passable eventually. One thing to say though: all is fine where the roof is bearing on the same wall both sides (my roofs are generally always pitched gable roofs) but if you have a different wall construction on one side you have no way of asking that half of the roof to behave differently. You have to Ungroup the Roof to convert it into two Roof Faces + then you can treat them differently BUT I have had issues with Roof Faces then going haywire + the components going completely AWOL + not being able to control the components at all. I recently submitted a bug about this. I think I find Roof Faces generally less stable/reliable than Roof Objects.

 

I’ve also had issues with Roof component offsets getting lost in translation when a model is imported into another file as a DLVP for example the rafter component suddenly decides (in the DLVP) to stick out the side of the roof + all you can do is make that component invisible.

[Gadzooks]

IMO, pitched roofs is another messy implementation of a tool VW knew they had to provide to users to be regarded as a 'professional' solution.

 

As you're finding out - its far from.

 

Meanwhile, deep in the basement of VW HQ, the memo that had "please sort the roof tool out" was buried by a new group of memos - one labelled 'bells' and its sibling 'whistles'.

 

@Christiaan and I have both struggled with some of the 'quirky' results using the tool can produce. His advice to break to Roof Faces is the action I'd love not to do, but I always have to,  just to start to make sensible resolution of the geometry. (Christiaan - "well Mr Client, I know you said you wanted a spectacular multi pitched roof over your development, but have you considered the simplicity of a lovely flat roof? Please, please, please.....")

 

I usually prepare a roof to look OK in straight (uncomplicated) elevations for submission to the client and Planning etc. The pitch and cover together with the resultant hips, ridges, valleys etc is enough to 'describe' the design. The detail always has to be drawn later - there's no way you're going to get a decent eaves detail from a section through a basic roof. However - many good roof companies will take your basics and return very detailed set-outs and fabrication drawings, so the option to provide 'design intent' can be preferable.

 

@TomW (just replied as I'm am tapping away) Big up on your experiences/advice.

 

Additionally, I would say its great to have the time (and fee) to break it down, as Christiaan says, and be able to even use the framing tool to get you part way (yes, its always part way with VW) to a detailed construction that can be peeled back (via hidden classes/layers etc) to impressive illustrations, understandable to clients.

 

See @Jonathan Reeves7 YT's.

 

Hope you get to feel you're more in control.

[ParkerJames]

Yup--basic elevation profiles and over the years I have just drawn 'details' of soffit and eaves and such and keep a library of them.

I have also found even in 2022 that 'Roofs' don't always behave.

[Matt Panzer]

9 hours ago, willofmaine said:

Possibly against my better judgment, I'm trying to learn how to use the Roof Object and Roof Styles.  It's been an uphill battle... like trying to climb up a 16:12 roof without a rope...

 

So I started from scratch in a blank file with four un-styled walls and an un-styled Roof.  Finally, I was able to (mostly) make sense out of things.  Then I proceeded with a Roof using (a Vectorworks default) Roof Style, and things went downhill from there (yeah, I fell off the roof), as I could not for the life of me control the fascia or soffit.  Ultimately I concluded that if I consider the Bearing Height and the Bearing Inset to be entirely meaningless, and set the Inset to 0" and manually position the roof at the desired height, I could get the Roof and its fascia to work.  The soffit seems to be an entirely lost cause.  See attached file for the progression of my attempts to get the Roof to work.  What am I missing?!?  @Christiaan and @Gadzooks, you guys seem like the rocket scientists of Roofs... maybe you have some answers?  Thanks!!  -Will

04-Roof Object Issues.vwx 3.82 MB · 12 downloads

 

Thank you, Will, for the file and laying out the issues!

While I believe most of these are known issues, I entered a bug (VB-184305) with the file to get this closer on the radar.

[ParkerJames]

On the up side---I am finding 'component' control of walls, roofs and slabs very helpful as nice profiles can be made using them.

[Gadzooks]

(can't seem to edit previous post)

 

@TomW @Tom W.  Sorry guys , the subtlety of your 'handles' evaded me. You know who your are!

[willofmaine]

Okay!  Thank you all for your responses!!  And it looks like, as they say, "it's not just me" that finds the Roof object, er, somewhat perplexing...

 

Historically I've paid little attention to wall and slab components and I've done my detailing entirely in 2D, and I've exclusively used Roof Faces, always modeling the eave and rake trim separately.

 

But a client's question has prompted me to explore the "BIM" approach of interactive walls, slabs and roofs and the possibilities of generating details based on their components.  While I pretty much knew from the start that the fascia and soffit accessories were of little value, I at least wanted to understand how they, and more importantly the Roof object in general, worked, all to the end of getting a Roof's components to interact with a wall (as depicted here: https://app-help.vectorworks.net/2022/eng/VW2022_Guide/Roofs/Creating roof_components.htm#h ).

 

I think I've got a handle on slabs and walls, but it looks like Roofs can only be part of a hybrid approach that would also include Roof Faces, 3D modeling, and/or 2D detailing/cleanup.

 

9 hours ago, Christiaan said:

 It's the kind of thing you get when programmers design in assumptions without a good knowledge of architecture. 

Yep.

 

9 hours ago, Christiaan said:

But I wonder if you might try modelling your roof with two Roof objects (not something I've tried). 

What I typically do (though with un-styled Roof Faces) is create the "upper" roof (typically about 1", representing, say, the sheathing and asphalt shingles) and then the "lower" roof (representing everything from the bottom of the finish ceiling to the top of the structure) (again, "components" are addressed with 2D details).  This leaves the eaves and rakes entirely free of any geometry other than what I'll model for them.

 

7 hours ago, Tom W. said:

...you just reach a point where you can’t take things any further + you have to live with something that's unfinished/unsatisfactory. 

So, pretty much just like any other Vectorworks PIO...

 

7 hours ago, Tom W. said:

Setting up the component offsets is another massive palaver

Ha ha, "palaver," - great word!  I'd never heard it before (too busy fighting with VWs...).  I'm not surprised at the many issues that you have with the Roof and even Roof Faces... especially given my experience with just four walls and a simple hip roof...

 

6 hours ago, Gadzooks said:

Meanwhile, deep in the basement of VW HQ, the memo that had "please sort the roof tool out" was buried by a new group of memos - one labelled 'bells' and its sibling 'whistles'.

Yep.

 

6 hours ago, Gadzooks said:

"well Mr Client, I know you said you wanted a spectacular multi pitched roof over your development, but have you considered the simplicity of a lovely flat roof? Please, please, please....."

Form follows CAD...

 

3 hours ago, Matt Panzer said:

Thank you, Will, for the file and laying out the issues!

While I believe most of these are known issues, I entered a bug (VB-184305) with the file to get this closer on the radar.

Excellent, thanks Matt!!

[Will]

Model it from scratch, you'll save time in the long run. The roof tool doesn't work for a lot of edge cases. It's ok for a rectangular bungalow with a hipped roof and big eaves overhang but not much else.

[line-weight]

Roof tool - useless except for very low level of detail at small scale

 

Roof face tool - somewhat useful sometimes, borderline whether it saves much pain compared to modelling from scratch. I sometimes use two or three roof face objects (ceiling, internal components, external layer) on top of each other as others have described upthread.

 

And yes the roof face tool is a classic example of vectorworks 90% functional = 90% useless. With some improvements it could become much more useful.

[Tom W.]

1 hour ago, line-weight said:

Roof tool - useless except for very low level of detail at small scale

 

I wouldn't describe it as useless. Admittedly my roofs are very simple affairs but I do manage a lot of the time to get something passable from the Roof Tool + if anything I think I prefer it to Roof Faces. You just very quickly reach the limit of what you can achieve with it + it's quite a slow painful process getting there. But I think with a bit of TLC it could become something really powerful + useful.

 

This is a recent Roof:

 

 

 

The wall plates, purlins + ridge board were overlaid in annotations but everything else was the Roof + Wall tools. The eaves detail is far from perfect but not to the extent that I'd completely write it off.

[line-weight]

Fair enough! But that's about as simple as a pitched roof can get geometrically. Do you reckon that was easier than it would have been, to do it with two roof face objects?

[Tom W.]

I have not used Roof Faces much because most of my roofs are very simple gable roofs as per the screen shots so Roof tool is actually quite good for this.

 

But I had another building in the same project where it was an L-shaped pitched roof where the front + back walls differed in thickness/build-up so I created the overall roof first as a Roof object then Ungrouped it to convert it into Roof Faces to allow me to treat each pitch independently in terms of the component offsets + weirdly one of the two faces behaved itself + let me do what I wanted but the other just went haywire + the components were shooting out all over the place + there was no way to adjust them. I just gave up, returned to a single Roof object + hand-drew the wall/roof interface at the eaves in annotations. Which was actually quite quick + satisfying + made me wonder why I wrestle for hours trying to get it done in the model! This is one of several recent problems submitted to tech support...

 

    

 

I also used Roof Faces on a simple flat roof but found the fact that component offsets are only applied to the bottom edge + not the sides really limiting. I expect the ridge to be untouchable as is the case with Roofs (not so much an issue with pitched roofs but a bit limiting with flat roofs) but to not be able to edit offsets at the verges is a bit rubbish. In the event I used two Roof Faces on top of each other as discussed elsewhere here + clipped them separately in plan as a means of applying edge offsets manually but this was after accepting I wasn't going to achieve anything remotely approaching accuracy when it came to wall/roof component interface.

[Christiaan]

Nice work Tom!

[zoomer]

4 hours ago, Tom W. said:

The wall plates, purlins + ridge board were overlaid in annotations but everything else was the Roof + Wall tools.

 

Nice.

 

Also you were lucky to choose one of the best looking chair type for Sections

when seen at a 45° angle 🙂

At first I thought these Chair Symbols were custom made,

until I saw the office chair 🙂

[Tom W.]

11 hours ago, zoomer said:

 

Nice.

 

Also you were lucky to choose one of the best looking chair type for Sections

when seen at a 45° angle 🙂

At first I thought these Chair Symbols were custom made,

until I saw the office chair 🙂

 

Ha ha the other thing that catches me out is all the different line colours used in these symbols, which you only discover when you render them in Hidden Line. You're trying to finish your sheets + find you have to go back to the symbols + edit the geometry + make all the lines black. Then remember to resave the edited symbol in your Favorites so the same thing doesn't happen again next time...