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View Full Version : Roof with flare at eaves - How would YOU do it?



3dway
2008-09-26, 05:03 PM
It seems to me like I can't do a roof by footprint if it has a flare at the eaves. It's a curved flare.

I tried by mass once already and it made a real mess of the geometry. Not easy.

Any suggestions would be appreciated.

Thanks.

andrewg
2008-09-26, 05:10 PM
Roof by extrusion...

Mike Sealander
2008-09-26, 06:35 PM
Also think about using void extrusions. When modeling in Revit, sometimes it helps to remember Boolean tools are available.

gwnelson
2008-09-26, 07:38 PM
how about a host sweep?

3dway
2008-10-08, 01:49 PM
Ok, I'm trying to do roof by massing it and using the roof by face tool.

It requires a lot of acrobatics. Solid modelling this way is even worse than in AutoCAD. Next, I'm going to try to import a sketchup model as the mass.

This is the simplified view. If I edit any of the masses, the voids show.

Basically I came to this by extruding a profile with the shape in one axis, then extruding a void perpendicular to that to get the hip.

The problems I'm having are:

-I can't see anything. Masses are rendered too tranparent to tell how they go together. It's like being forced to work in wireframe, but not being able to see the lines between masses. You go into one mass to edit it and all of the edges of the other masses disapear.

-I am forced to make this our of a few separate masses so that the voids of one mass don't cut the the other masses.

-I beleive that I have the faces the way I want them, after struggling to model this way, now it won't make the roof. I just get a "can't make roof" error. Expanding the explanation doesn't explain the root of the problem.

I'm used to modelling in 3dsmax, sketchup, silo, modo, even autocad. This is a brutal modelling tool.

Can anyone suggest ways, to get it to display more clearly? to find the reason I'm getting the "can't make roof" error?

The problem here is the curved flare at the eave. It pretty much makes the standard roof tools useless. The relationships of the forms are important, such as, the gable "dormer"s on the ends hit the roof at the point where the curve stops.

I thought about sweeping the flare then using the standard roof tools from there up, but it's really really difficult to get the points where these things all have to intersect.

I've spen a full day massing this and then get slapped in the face with a "can't make roof" error with no explanation. this is the kind of stuff makes people want to go back to AutoCAD.

3dway
2008-10-08, 02:00 PM
Here's more of what it should look like.

Sorry about cutting off the whole view. In my mind it helps to preserve the client's privacy somewhat.

3dway
2008-10-08, 02:56 PM
Ok,

It looks like Revit "likes" to make the roof better, one face at a time.

It doesn't join up as nicely, and I hade a couple of situations where I had to go into masses within masses to make sure everything was joined.

Is there any way to cut off bits of roof that stick inside? Some of this isn't going to section nicely and it's kind of sloppy.

Munkholm
2008-10-08, 06:28 PM
I´d do it by creating the 15-20 (roughly estimate) seperate roofs, created by footprint, and then use the join roof tool. That should be possible, and give you true section views.

3dway
2008-10-08, 06:56 PM
I´d do it by creating the 15-20 (roughly estimate) seperate roofs, created by footprint, and then use the join roof tool. That should be possible, and give you true section views.

You mean do each pitch / plane as a roof by footprint based on a one line sketch?

3dway
2008-10-08, 07:15 PM
Just tried. I have to do closed loops for a roof by footprint.

Munkholm
2008-10-08, 07:40 PM
True, you have to draw closed loops - but it´s possible anyway, just unmark the "defines slope" option, for those lines which is not at a "gutter edge"
(Sorry, not sure how to explain this in prober english, but see atachment - hopefully that´ll give you an idea)

3dway
2008-10-09, 02:37 PM
Thanks.

The difference here is that the flare is curved.

I'm making some progress. I used an in place family for the curved flare. I suppose that I could have used masses and roof by face for this. In fact, in one place where the roof has to overrun the flare and the fascia dies into the flare, this is what I did.

I will post some progress.

BigBadBIM
2008-10-09, 05:51 PM
Had a couple of minutes to play with the idea...

Does it comes close to what you are looking for?

3dway
2008-10-09, 06:21 PM
Had a couple of minutes to play with the idea...

Does it comes close to what you are looking for?

Thank You, Very very close.

Mine is complicated in a couple of places though. The main hip in interrupted on one corner by the entry gables. Where the main roof is 10ft. the entry is 12ft. It's like a regular hip by footprint but on one corner the eave has to change to 12'.

Lewerim, what method did you use for this?

Thanks again.

mthurnauer
2008-10-09, 06:21 PM
Lewerim:
Did you sweep the curved portion around the perimeter? I was going to suggest that it makes more sense to build the roof and then swep the curved part because it would more accurately reflect how the roof needs to be built. The rafters of the hip roof need to sit on a top plate and then the sweep is framed out of rafter extensions/ and sleepers. I would model the roof with no overhang and then sweep the eave around the perimeter.

BigBadBIM
2008-10-09, 06:27 PM
Yep. I modeled the roof>by footprint.
Created an in-place family (category roof) Created a sweep that the path is the edge of the roof.
To get rid of the "join" line between the two roofs, I (hangs head) used the linework tool and invisible lines. I couldn't get the roofs to "join" though.

3dway
2008-10-09, 06:28 PM
Here's where I got to.

The curved flare is a sweep. It's an in place family now, and I need to be able to put a fascia on it, so I'm looking for a way to convert it to a roof. Afterall, it's the same solid modelling tools that make it. Should be possible right? I get "can't copy between family and project" If I try to paste it in as a mass. Must be another way.

BigBadBIM
2008-10-09, 07:21 PM
Here's where I got to.

The curved flare is a sweep. It's an in place family now, and I need to be able to put a fascia on it, so I'm looking for a way to convert it to a roof. Afterall, it's the same solid modelling tools that make it. Should be possible right? I get "can't copy between family and project" If I try to paste it in as a mass. Must be another way.


So, I selected the in-place family>clicked edit> selected the sweep and copied the sweep (not the inplace family, that wouldn't copy and paste between family and project, but the sweep would.)

Opened a new family <Mass> template and pasted it in. It didn't show up. By chance, I clicked <place mass> in the design bar and it said "no mass loaded. would you like to load"

What I noticed was that the sweep showed up then. So I clicked <No>

I don't know why it worked, but it did, and I was able to reproduce it. I loaded that into the project and then created a roof by face from it.

In the second picture below the RED arrow points to the new roof by face, the Blue to the Mass component family, and the black to the generic roof object.

I'm still playing with it though. This is a good one! :)

3dway
2008-10-09, 07:46 PM
The other problems I'm having is when trying to attached the gable/dormer parts, they won't join if they're flush fasia to fascia, or if a a roof plane is aligned; ie the same plane.

I'm still not getting a result that I can section neatly. Fascias stick though, there are parts of roof underneath that don't belong. I don't have any more time to waste modelling the roof on this one. I'm either going to have to draw over everything with lines in 2d or go out into autocad.

I want to believe in revit, but this roof is simple by our standards. The modelling tools are behind the current standard in the industry. Right now it feels like it's a struggle to do things that are not rectilinear with flat or simple roofs.

Another struggle with roofs is that we have stepped fascia details where the sheathing overhangs and is clad with a metal drip edge. It looks to me like in revit I need to be able to do two roofs (or is it rooves?). I want to show the top chord as part of the roof. I need the sheathing to overhang and I'll do the bottom chord as part of the ceiling I suppose. I'm having trouble with the location line for the roof too. I assume that if I modelled the roof from the face of a mass, that face is the location line. If I've done a roof by footprint, can I control if the roof goes up or down from the footprint? Rightnow my roofs are just sheathing located on the exterior face of sheathing. If I change them to a roof assembly thickness, they jump around and screw up the dormer openings.

I know one of the phases of Revit Userhood says, "you know what Revit likes and doesn't like" but I can't change designs because Revit doesn't like modelling that. The boss signs the paycheques and if he likes gables with flush fascias, I have to be able to do it, even if Revit doesn't like doing it. One of the dangers I've been warned about is a BIM tool beginning to dicate design. Sorry, nearing the seventh hour of fighting the software to get this roof done ....again.... and I'm going off on rants.

Thanks for the help. It is much appreciated.

BigBadBIM
2008-10-09, 08:09 PM
Well, I got this far (see pic)

Not sure about some of the problems your having. Roofs (and it IS roofs :) ), especially this kind of roof, are hard in Revit. But then this kind of roof is hard in AR (actual reality.) I started out swinging a hammer and this kind of roof is far more involved to build, so it stands to reason that it is more involved to model. That said, after you build a few of thsese (in either VR or AR) you get good at it and you can pull it off like it's no big deal. THAT's the secret of craftsmanship... Skill and knowledge are the sum of your experience and experince is the sum of your mistakes and struggles.... :lol:

That doesn't solve your problem, but don't get discouraged and throw in the Revit towel yet...

Have a cold one and come back to it later.:beer::beer:

BigBadBIM
2008-10-09, 08:10 PM
And since it was one more post the 100 club, I cpouldn't resist. :mrgreen:

BigBadBIM
2008-10-09, 08:51 PM
So, as often happens, you find the simplest way to skin the cat after you find the hardest.

Try this:
Roof by extrusion>Selct the roof>Click Cut Work Plan> Cut to 45 deg> Mirror using the 45 as the mirror line. Simple and sweet. :lol:

3dway
2008-10-09, 09:32 PM
Thanks for all of your effort on this one.

That cut work plan thing will come in handy, I'm sure. Though sweeping the flare along the path was simple and eliminates a step for each corner.

...time for a cold one indeed. I'm stuck at that in between where I can't reap the benefits of building this thing yet. All I have to go on is the modelling part of the software, and I can compare that to learning several other 3d packages. Once I get to the harvesting information and scheduling advantage, revit will be alone in it's class I'm sure.

Thanks again everyone.

3dway
2008-10-21, 12:28 PM
Please have a look in this thread that I replied to. My roof is inside out, I think. The texture is mapped correctly on the inside of the roof and my fascia goes on backwards. Though I can flip it, I think it's a symptom of a greater problem.

http://forums.augi.com/showthread.php?p=902081#post902081

3dway
2008-10-21, 12:38 PM
Ok, maybe it's just the lighting and the bump mapping.

It's still going to be a problem. The colour seems wrong on the outside and the bump mapping is either at just the right angle with the light that nothing shows, or something is wrong on that side. Even if the bump mapping isn't showing, shouldn't the diffuse map show the lines in the shingles?

I'll go look at the diffuse image to see if it has lines. It's a default.

anugouba
2013-08-04, 07:59 AM
You mean something like this? I am from South Africa, here we know it as Bali roof. It's quite simple, just create one roof above the other and give each a different slope from each other. Sorry I answered late, just joined. Hope this answer's your question?