Auto Roofs and Overbuilt Planes

[KTransue]

 

Just trying to practice on something new on this Monday morning … I've read comments from those who have been more successful than me that 'if I understand how Chief does roofs, I can create just about any roof using auto roofs'. Recently I tried using auto roofs only on a complex multi-plane roof in which the visible portion of one particular plane never touches any wall.  I failed.  So, today I tried it on a much simpler roof over a "saltbox colonial" with a full-width front porch's shed roof intersecting the main roof's front (hip) plane.  I'm failing again, this time with regard to overbuilt planes.  If it helps any, I've included a quick screenshot image of the porch roof interaction, which is the at same width as the main roof (both the main roof plane and the overbuilt shed roof plane are aligned at the gable edges and both are visible from the side view).  Using auto roofs, the resulting planes keep shifting the main peak to meet the porch roof instead of honoring the main roof and adding an overbuilt shed roof intersection.  Any words of wisdom?

 

[Kbird1]

assuming I understand the situation .......

 

The Porch Wall should have the Upper Pitch enabled ( input main house pitch)  and the Baseline distance set to the width of the Porch

so the pitch change happens over the Exterior Wall

 

This is useful only with Auto Roofs I think......

 

Mick.

[KTransue]

4 minutes ago, Kbird1 said:

the Baseline distance set to the width of the Porch so the pitch change happens over the Exterior Wall

Thank you for helping me think this through, but I don't want the pitch change to happen over the exterior wall ... Actually, I don't want to have to determine where the pitch changes at all.  It should change wherever the two pitches come together, or it kind of defeats the whole automatic roofs thing.  I'm hoping I'm once again missing something simple, like a checkbox that I didn't notice has been there for a dozen versions (e.g. "Overbuild Roof Plane? -- Yes/No")

[KTransue]

@solver, rumor has it that you're the master at auto roofs, so when you tell me it's not currently possible then I know I can give up.  (sigh)  I had high hopes that I was going to be utilizing wall settings and auto roofs for everything.

 

I'm reminded of something Dan Baumann once taught me:  "Auto Roofs will get somewhere between 0 and 100 percent of your roofs correct."  haha!

 

I do appreciate you taking the time to point me toward that link, even though the suggestion is now three years in the making.

[Ridge_Runner]

59 minutes ago, KTransue said:

 "Auto Roofs will get somewhere between 0 and 100 percent of your roofs correct."  haha!

Now that's funny!

[Alaskan_Son]

Its not clear to me whether you're looking for roof planes that join or roof planes that remain separate.  In other words, are you looking for a dual pitch roof (i.e an automatically calculated upper pitch) or are you looking for a second roof plane that simply sits independently on top of the first?

[Kbird1]

1 hour ago, KTransue said:

Dan Baumann once taught me:  "Auto Roofs will get somewhere between 0 and 100 percent of your roofs correct."

 

More like 65-100%   ------  100% if you have a square box  , no porches or deck etc.....

 

I didn't understand by Overbuilt you meant a California Frame Over , as it is called in some areas, Chief has never Over-Framed Auto AFAIK ......

 

However the two Pitch Roof should give you what you need as far as roof planes if not the way it is built ( framing) in the realworld

at which point a Truss Base can be used to overframe I think....

 

https://www.chiefarchitect.com/videos/watch/350/using-a-truss-base-to-truss-intersecting-roofs.html 

[KTransue]

@Alaskan_SonMichael, the term we use here is "over-built" or "over-framed".  In effect, it is a roof plane that is framed -- in some part -- above another roof plane, and the second plane ties into the first plane at one or more places. In this case, both ends of the primary "salt box" roof shape are visible, as are the ends of the roof over the two-story porch that die into the other roof about ¾ of the way up to the peak. But, what I'm really trying to do is understand where the capabilities of automatically generated roofs succeed and where they fail.  I've read that auto roofs can work 100 percent of the time, but my testing proves otherwise.  As always, I'm happy being proven wrong ... especially when I can learn from it!

[Alaskan_Son]

Just now, KTransue said:

I've read that auto roofs can work 100 percent of the time

 

This is absolutely incorrect.  Whoever wrote that was just plain wrong.  Anyway, for the example you've posted, it takes a matter of seconds to do manually.  For a dual pitch roof, there are some tricks to very quickly find the upper pitch intersection so you can plug it into the Roof directives. 

 

[KTransue]

4 minutes ago, Alaskan_Son said:

for the example you've posted, it takes a matter of seconds to do manually

Thanks, Michael.  Yes, I know that it's a straightforward exercise for manual roof builds ... I just wanted to see where auto roofs succeed and fail.  Thank you for your thoughts ... always appreciated!

 

[KTransue]

12 minutes ago, Kbird1 said:

a Truss Base can be used to overframe I think

Thank you @Kbird1 ... The truss base may be a reasonable approach, even in this very simple case ... though I'm not sure if they'd require more tweaking or less tweaking then the simple shed roof dieing into he main roof, and then pulling down the main roof slope to the baseline, especially when the both ends of both roofs are to remain visible.  Might have to play with it just to see.  Either way, auto roofs couldn't handle it, which is what I was trying to determine.  Thanks again.

 

[Alaskan_Son]

24 minutes ago, KTransue said:

I just wanted to see where auto roofs succeed and fail.  Thank you for your thoughts ... always appreciated!

 

You bet.  For the record, this CAN actually be done with auto roofs, it's just not worth the hassle in my opinion...or I don't know, maybe it is.  Probably depends a bit on the rest of the project and on how likely the other roof planes are to change.

Quick Example.plan

[KTransue]

Dammit, Michael!  What did I miss?  What is making the porch's shed roof stop at that particular point as it climbs the slope?  That is, if I change the pitch to, say, 5:12, it still stops at the same point (and just hovers there above the other roof).

[KTransue]

Plus, you magically modeled my wife's she-shed!  haha!  

 

 

[Alaskan_Son]

23 minutes ago, KTransue said:

Dammit, Michael!  What did I miss?  What is making the porch's shed roof stop at that particular point as it climbs the slope?  That is, if I change the pitch to, say, 5:12, it still stops at the same point (and just hovers there above the other roof).

Therein lies the rub.  The devil is in the details when forcing automatic roofs to do things they weren’t really designed to do. In this case, it requires using an extra wall, using multiple roof groups, and to answer your question more specifically, it requires setting that intersection in question by using overhang dimensions.

[KTransue]

3 minutes ago, Alaskan_Son said:

forcing automatic roofs to do things they weren’t really designed to do

... kind of defeats the purpose of "automatic" roofs!  haha.  Thanks for the craziness.

 

[Alaskan_Son]

10 minutes ago, KTransue said:

... kind of defeats the purpose of "automatic" roofs!  haha.

 

Yes and no.  In this case I can certainly agree, but then again, where do you draw the line?  Complex auto roofs usually require placing gable lines, placing wall breaks, going into multiple dialog boxes, changing various settings, etc.  Is this really that much different just because a couple of the extra steps are out of the norm?  Its all time consuming.  We just have to decide on a case by basis where to draw the line.  For me, I guess that line typically lies wherever I have to place a wall break or draw an otherwise unnecessary wall.

[KTransue]

58 minutes ago, Alaskan_Son said:

it requires setting that intersection in question by using overhang dimensions

... I'm not seeing where you're setting that intersection in question using overhang dimensions.  Enlighten me?

[glennw]

Seems like Michael and I maybe thinking along the same path.

If so... the overhang is the overhang on the top of the shed roof that roofs the porch.

Auto roof can get you most of the way there.

The fact that it is difficult to do with auto roofs is usually a red flag to me that the roof would be difficult to build in real life.

In this case, how would you build it?

Almost, if not impossible to build! (I am particularly talking about the gable overhangs) 

[KTransue]

@glennwActually, the construction is pretty straightforward and quite doable and, in fact, already exists.  The challenge was to see if Chief's auto roof generation could determine the intersection point and self-tweak that intersection based on changing pitches of the main roof and the porch roof -- it couldn't.  If it could, then the designer could play with different pitches to achieve the desired aesthetic without having to intervene to modify and complete the joining of the planes.  This happens to be an existing home that we're doing some redesign in, but I was just using it as a test bed because "it looked like an easy one" to check the capabilities of Auto Roofs.  Haha!  Fooled me!

 

[KTransue]

Thanks once again, Eric.  That is, as the video says, "a powerful tool when you want to manually edit roof planes", and I appreciate the thought.  My quest was to achieve these intersections without manually editing the roof planes, but that's really not a practical reality.  A very good tip, none the less!

[Alaskan_Son]

4 hours ago, KTransue said:

My quest was to achieve these intersections without manually editing the roof planes, but that's really not a practical reality.  A very good tip, none the less!

 

The thing is that you can use things like that with Auto Rebuild.  You don't need to turn the auto feature off to utilize temporary points.  You just have to think a little outside the box.  You use the temporary points to quickly find things like required Overhang settings, required Upper Pitch In From Baseline values, etc.

 

 

5 hours ago, KTransue said:

... I'm not seeing where you're setting that intersection in question using overhang dimensions.  Enlighten me?

 

I put the deck room into a different Roof Group so that it would generate it's own roof independently of the main roof.  The problem though is that the main roof needs a Hip Wall and the Deck roof needs a High Shed/Gable wall, so I drew in a .01" thick invisible wall at this location....

...that's the wall controlling the overhang. 

 

By the way, there are other options as well such as using Roof Baseline Polylines. 

[KTransue]

4 hours ago, Alaskan_Son said:

use things like that with Auto Rebuild

Got it.  Just can't "automatically generate" a whole roof system without manual intervention, letting Chief figure out the details.  That's fine ... I was just trying to see how some felt that you could pretty much build any roof automatically.  Simpler roofs, yes.  But more complex roofs, no.

 

4 hours ago, Alaskan_Son said:

so I drew in a .01" thick invisible wall at this location....

Oh, you sly dog ... Definitely didn't see THAT one!  Thank you.