davidstvz

Using Roof Baseline Polylines

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Is there any detailed documentation about roof baseline polylines and how they work?  I can't seem to find anything, but have got a lot done just by tinkering.

 

One question I have is, where should the polyline typically stop on exterior walls?  When generated automatically, it seems to go to different areas (sometimes to the outside of bricks, sometimes only to the outside of framing, sometimes to the inside of framing).

 

Overlapping doesn't seem to cause any problems, in fact, sometimes it seems essential to solving problems.  For example, the green outlined section in my attached image is a hip roof over an area with 12 foot ceiling, while the neighboring areas have 10 foot ceilings.  Getting the southern edge of the hip plane to form a proper valley was impossible without overlapping the polyline on that side.

 

I've taken to creating multiple independent and overlapping baseline polylines to get the roof I want.  It's been especially useful in sections where there are two different pitches projecting from a single long wall (the automatic system seems completely unwilling to do that; it always just ignores one of the mismatched pitches along the wall).

 

It seems like you ought to be able to simply draw a new roof baseline polyline, but I haven't found any way to do that.  Instead, I just create a simple rectangular temp structure and then copy and paste it's baseline polyline as needed.  At least that automatically sets the baseline height (it generates at 9 and 9/16 inches above the absolute ceiling elevation if you need to set it manually).

roof-baseline-polylines.png

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You are miles ahead of me, I'm still just learning the terminology. I have my house plan drawn but when I started making changes on the roof I started to loose my mind. Im on a bit of a time crunch so I'm hoping to learn from other comments on this tread. this is only day 2 for me. So far I'm loving the program

Thank you, Jo 

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Here's something to get you started.  Go to the menu and click:

 

1) Build -> Roof -> Build Roofs

2) Select auto roof and "make roof baseline polylines"

NOTE: if you ever want to go back to a normal auto-roof, you have to get rid of the roof baseline polylines you just created.  The easiest way to do that is from "Edit -> Delete Objects".  Just click "roof baselines polylines" check box and confirm, then build roof again but without the baseline polylines checked (or check it again to regenerate new ones).

3) To actually see the polylines, you need to go to your plan display options and then enable "roof baseline polylines".

 

Finally, I find that the easiest way to see the roof is using a full orthographic overview and then just rotate the camera to be looking straight down (pan the camera by holding the middle mouse button until you're centered over the house and zoom in with the mouse wheel to get the kind of view in my attached image; consider temporarily painting the roof ridges with slate tile as I did to make them easily visible).

 

Now using the "window" menu, split your view to a vertical layout with the plan on one side and the orthographic view on the other.  Now you can easily see how changing the polyline changes your roof.

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You can do as you wish (I know I do). I have been using and teaching this software for about 25 years. They added the Roof Polylines tool about ten years ago. By that time I already knew how to set up for auto-roof generation using ceiling heights, Wall Specification Dialog - Roof Tab settings and using the gable line tool, and I already knew how to manually edit and build roof systems, so I never bothered to study that tool or use it.

That does not mean that if one bothered to carefully read its documentation in the Reference Manual and then practice using that tool that they could not expect to get good results. I often help new users straighten out their plan files and roof system and of course the FIRST thing I delete, once found, is the roof polylines that are always 100% the cause of the new users being able to get a desired product. You and I both are free to do as we wish.

 

The common denominator of New User troubles is lack of actual study, followed by practice to verify that they now understand what they are doing and how to do it. Most new users just guess and hope for the best and the usual outcome is pleading questions here and unwanted results. Whatever you do, please study a tool, practice using that tool until you are certain you understand how to use it before you inflict its use on your plan file (create test plans to use for study and practice.) I am being honest with you, please be honest with yourself.

 

DJP

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I agree that one should read the manual and try to understand the tools, but it's not always easy to do.  Tinkering has always been my means of learning computer programs.  It does occasionally get you into trouble unfortunately.

 

Well, if no one else is up to the task, I will post info about what I think I've learned about roof baseline polylines here.

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Attached are the two pages about "Roof Polyline" how to use, etc , once I read what the tool does I again decided that I do not need it since I have already learned how to manually edit and create roofs. You be the judge. It is only two pages of the whole 2,000 plus pages of the Reference Manual, take a look please.

 

DJP

Roof Polylines Section.pdf

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I’ve already read those two pages, twice actually. I agree it’s good to read the manual, but it’s very limited here. 

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Here's a summary of what the manual says (roughly) about roof baseline polylines:

 

1) How to create and display them in the first place, and that you'll get at least one baseline polyline per wall height in your exterior wall layout. 

 

2) It tells you that editing (changing the shape of) roof baseline polylines is much like editing any polyline (which is almost true).

 

3) It mentions that the baseline polyline edges have roof directives just like exterior walls.

 

4) There's a very simple example where a porch is created which is probably better addressed via other means (such as using railings or room dividers to define the porch so that it has a roof overhead automatically). 

 

 

What it doesn't say:

 

They never really gives you a good reason for why you might use them and very little guidance on how to use them:

 

1) With regard to editing the baseline polylines, they forget to mention that edges set to "Vert-V" (i.e. against wall) are forcibly aligned at right angles to the grid and their vertices cannot be combined to simplify the polyline.  If you need to remove a vertex, you need to set both adjoining edges to hip and then combine the vertices.

 

2) The automatically generated baseline polylines may be needlessly complex if you have two or more different ceiling heights along the exterior walls.  The polyline will follow the shape of the interior rooms which match its height (marking each edge with "Vert-V") whereas the roof system is probably only using directives in the exterior portions of the polylines.  The only purpose of the interior portions is to ensure that all portions of the structure are covered, or to set some sections to non-hip on occasion.  It may be preferable to create your own much simpler set of baseline polylines and allow the interior portions to overlap for the sake of simplicity.  Just don't leave a hole in your set of polylines as that will create a hole in your roof.

 

3) It doesn't tell you how to manually create a new roof baseline polyline, which makes sense because I don't believe you can do so directly.  Fortunately, you can copy and paste existing ones.  I recommend making a simple rectangular structure as I said above so you can copy and paste it's roof baseline polyline as a way of creating new ones (if needed). Remember to increase the height if needed.

 

 

Best reasons to use roof baseline polylines:

 

1) It would be a good idea to work with wall directives first and learn how those work before using baseline polylines as most of the time you can get done what you need with the wall directives.  However, if your auto roof is not behaving as expected, one strategy might be to generate the polylines and then inspect them manually to see where your problems are (and use what you learn to correct the directives in your exterior walls, delete the polylines and go back to a normal auto-roof).

 

2) Your roof section with a different height is not behaving as expected. I've been able to fix some issues that, so far, I am unable to fix with wall directives, though I'm not prepared to go into detail about this yet because I'm really not sure what the problem is yet or how I fixed it.

 

3) You cannot have two different pitches emanate from one exterior wall.  If you generate the baseline polylines, you can see that it choose one of the two pitches and makes a single polyline edge.  Even if you manually create two separate roof baseline polylines with different pitches, if two edges are coplanar and the baseline is set to the same height, the auto-roof will only generate one plane using one of the two pitches.  To force two separate pitches, you need to bring one of the two edges inward just a bit (if you don't bring it in too much, the roof edge remains flush thankfully).  I will attach an example (the house I'm living in is designed this way).  Notice both the left and right exterior wall sections change from 12 over 12 to 9 over 12 pitch seamlessly.

 

Edit: DJP, I'm curious if you can generate the roof in the attached images without using manual edits or baseline polylines.  All ceilings are at 10', except the front porch is at 12 feet and the room/wall immediately to it's west is at 11 feet.  The house plan actually specifies a 9/12 pitch everywhere, including all around the edges (just for the 18" or so inches it takes to reach the exterior walls) then a change to 12/12 on the following east/west facing planes: the pair over the garage, the large pair over the main body of the house, and the pair over the front porch.  All north/south planes are 9/12.  It seems the only way to make two different pitches happen on a wall is to split the exterior wall and move part inward 3 whole inches.  With baseline polylines, you can create the separate pitches by moving a section inward the slightest fraction of an inch.

 

 

 

different pitches.png

ortho-view.png

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9 hours ago, davidstvz said:

DJP, I'm curious if you can generate the roof in the attached images without using manual edits or baseline polylines.

 

That is an extremely simple hip roof system which one should be able to autogenerate, provided that the settings that YOU input are correct. It should take less than five minutes to do after you learn how and where and what the settings are designed to do, no manual editing, and no roof polylines. 

 

 

DJP

PS: thank you for making me study and find out what "Roof Polylines" are for and how they are to be used. Now that I understand how they work, I believe I was right in the first place to not bother to learn them since I already knew how to get auto roofs and manual roofs. Roof polylines are for creating asymmetric roof systems which I do not favor and can do anyways using manual tools.

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10 hours ago, DavidJPotter said:

 

That is an extremely simple hip roof system which one should be able to autogenerate, provided that the settings that YOU input are correct. It should take less than five minutes to do after you learn how and where and what the settings are designed to do, no manual editing, and no roof polylines. 

 

DJP

PS: thank you for making me study and find out what "Roof Polylines" are for and how they are to be used. Now that I understand how they work, I believe I was right in the first place to not bother to learn them since I already knew how to get auto roofs and manual roofs. Roof polylines are for creating asymmetric roof systems which I do not favor and can do anyways using manual tools.

 

I agree, it is a straightforward hip roof designed by a professional architect which I am not.  However, I don't see any way to auto-generate it from wall directives.  In particular, how do you create two different pitches along the same wall (as in the east and west walls of this structure)?

 

I personally find the baseline polylines to be a very intuitive system with more ease and power than wall directives while being not nearly as complex as manual roof editing.  If you've mastered manual roof editing, I can see why you would disregard it, but there are a lot of amateurs here who can benefit from it.

 

 

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5 hours ago, davidstvz said:

However, I don't see any way to auto-generate it from wall directives. 

 

For Hip roofs None Are Needed!!! Just set your ceiling heights where you need  roofs at varying heights. Home Designer software and Chief Premier both create hip roofs by default!

 

DJP

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The ceiling heights are the same in that area. I suppose if I played with room heights I might convince the system to generate that roof, but would that really be the best/right way to do it when the exterior walls are supposed to be at the same height? I think baseline polylines are far more appropriate here since changes to them only effect the roof.

 

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3 hours ago, davidstvz said:

The ceiling heights are the same in that area. I suppose if I played with room heights I might convince the system to generate that roof, but would that really be the best/right way to do it when the exterior walls are supposed to be at the same height? I think baseline polylines are far more appropriate here since changes to them only effect the roof.

 

 

Without a copy of your plan and a photo of the front elevation of this home, know one could otherwise than guess. Do you have an image of that the front of the home is supposed to look like? Share it please.

 

DJP

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3 hours ago, davidstvz said:

The ceiling heights are the same in that area. I suppose if I played with room heights I might convince the system to generate that roof, but would that really be the best/right way to do it when the exterior walls are supposed to be at the same height? I think baseline polylines are far more appropriate here since changes to them only effect the roof.

 

 

Without a copy of your plan and a photo of the front elevation of this home, know one could otherwise than guess. Do you have an image of that the front of the home is supposed to look like? Share it please.

DJP

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Posted (edited)

I can upload a plan either late tonight or tomorrow morning.


You don’t really need elevations through. Rooflines should all be at the height required by 10 foot walls/ceilings, except the front “stoop” which has a 12’ ceiling and roofline to match, and the section between garage and stoop which is at 11 feet.


Roof pitches are all 9/12 except (assume the top of the plan is north) east and west facing planes are 12/12 over the garage, over the front stoop and over the main body of the house (so back porch is all 9/12; and the section connecting garage to house is 9/12). Also, the 12/12 sections I just mentioned all begin with a 9/12 pitch for about 18 inches before switching to 12/12.


The top down view of the roof I posted is accurate except doesn’t include the 9/12 at the bottom of the 12/12 sections. I’ve since added that using the upper pitch feature.


Really though, just make a a long rectangular “house” with two different roof pitches along the same wall if you can. That’s the main thing I’d like to see if it can be done.

Edited by davidstvz
Correcting text formatting

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In case anyone is interested, the documentation for RBL (Roof baseline polylines) is much better for chief architect than for home designer pro. Here’s a good instruction page and a training video I found:


https://www.chiefarchitect.com/support/article/KB-00543/utilizing-roof-baseline-polylines.html

 

https://www.chiefarchitect.com/videos/watch/706/roof-baseline-polylines.html

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