Tensile Roof Structures

[Steve_Stafford]

I'm curious what technique if any, folks have used to accomplish this type of roof. I've got a project that seems to want such a roof and I'm interested in ideas. I've attempted a couple with revolves, sweeps and blends. While close it's not very satisfying yet. It needs to "look" convincing from a 3d perspective and elevations and probably rendered.

I'm also considering an AutoCAD surface model and imported...

This roof will have four quadrants, a rectangular "base" with a central pole in quadrant. Each will/should be modeled separately?...

Ideas?

[Allen Lacy]

It's a wild idea and I haven't tried it, but could you use a topo surface?

[beegee]

Steve,

This topic (www.zoogdesign.com/forums/phpBB2/viewtopic.php?t=948&highlight=roof#top) may help.

[gregcashen]

Having played with that method, I can assure you it opens Revit's modelling capabilities up in a huge way. It will not allow all fabric type structures, but it will allow for many shell type structures.

[Alek Sutulov]

I've gone through that exercise last winter and suggest you wait and see if 6.0 will have better ways. It could be done to some extent using topo tools with a lot of manual calculations

[Steve_Stafford]

Greg...check these out, I think I'll be able to fake it with some variation of these. Just sweeps along a square base with voids to put the curve in the edges. A little tweaking and a little rotating to "tip" them a bit should be "good enough" for now. Just conceptual anywho...

Oh, Allen, I tried a topo surface first, but it is just too erratic to layout. I suppose I could layout grid to place points "accurately" to represent it but the sweeps etc are more polished looking so far.

[beegee]

Rather large columns to hold up those teensy tents Steve.

Maybe Greg will design some nice thin elegant ones for you ? :lol:

Nice work though, and applies the famous KISS principle very nicely.

[Steve_Stafford]

Why....they're large because there is a lot of wind of course, yeah that's it...teeny to you, but to those ants they look positively huge!

[beegee]

Steve,

Check this out.

[Steve_Stafford]

I see yours and I raise you one amphitheater... courtesy of www.birdair.com

[beegee]

Yes, but mine trumps yours, cos mine's lightweight n'elegant.
8)

[Steve_Stafford]

I was working toward a "fullhouse" hehe

You mispelled your description...you meant lightweight and inelegant right?

[beegee]

Fullhouse or outhouse ?

[gregcashen]

Dr. Nurb, huh? I was going to suggest In-place Idiot, but it seemed a bit inappropriate, as I can be an idiot all over the place.

As for the roof...I am playing with something that might work out...it takes a while to set up, and I am not sure it is going to look quite right, but I should have it for you at AU...unless it sucks.

By the way, do you want to have the roof the way you modelled it or the way it is in the birdair picture (upside down)??

I think that the best tool for this sort of thing would basically be similar to the topo tool in the sense that you would basically place your corners at a preset elevation and then you could place internal points and pull them up, down, left, right...instead of simply interpolating the intermediate contours, it should act like the spline tool, i.e. it would stretch the "fabric" based on the location of the "grips". Anyway, we can mention it to David at the family editing session, I guess...

[Steve_Stafford]

I agree your description of a roof surface tool would be cool.

As for the BirdAir roof, there is another picture somewhere on their site that shows it from the front "elevation". The roof is pretty tricky. It rises to points and falls to points as well. It appears the the spouts empty into columns and probably handle drainage as well, while the peaks are supported by an interior truss and "derrick crane" structure (sort of) with liberal amounts of guy wire stays.

Pretty neat really. I put in a call to BirdAir to see what they'd propose.

Thanks for your effort...glad you are having fun experimenting.

[Steve_Stafford]

Back from AU...charged up...letting out some steam so here's "some" progress on the woofs...still need some tweaking but it's getting close enough for this phase.

[gregcashen]

Alright! That looks great. Not a bad approximation given the lack of any method to create the double curvature with the limited tools we have for this kind of stuff. One thing that may give it a more "tensile" look is to cut the edge at the chamfered corner with a more rounded void so that it looks like it is being "pulled" more. But all in all, it looks better than any of the approximations I was able to come up with using blends and voids.

:wink: