Twisted Blend Roof.

[Alek Sutulov]

I need to create a twisted roof surface like shown on "twisted" jpg. But none of the edges are paralel to each other as per frame axonometry on "frames" jpg (3 frames to the bottom right are typical condition).

[gregcashen]

You can do this with a blend. But it is not at all straightforward to explain. Try making blends with the start and end profiles shaped as your roof slab, but rotated to align to your beams at each end. the roof will bend as needed. Try it and let me know if you have problems...

[Alek Sutulov]

I tried by setting top blend plane along one frame but it seems imposible to set bottom plane along second frame which isn't paralel to frist. Looks like blendings planes are set appart by blend depth which means they have to be paralel.

[gregcashen]

Make it oversized and then use voids to cut the plan shape as you want it.

[Alek Sutulov]

It almost worked Greg. Thanks

[Scott D Davis]

Did you try a ruled curtain system? I'm not sure what material you are trying to make these, but the ruled surface may work. The panels can be anything you want. It's going to create a panalized system, which is probably closer to how you might actually build what you are attempting to model. Will your roofs actually be pefectly smooth double-compound curve "twisted" elements?

P.S. The more panels, the smoother the curve and panel joints will be.

http://www.zoogdesign.com/forums/phpBB2/download.php?id=1778

[Alek Sutulov]

Roof structure is metal roof deck spanning over steel frames sloping in oposite directions. There shall be rigid insulation over it covered with roofing membrane. So the look can't be panelized. But I'll try it tomorow.

All but 2 frames are paralel to each other and I have no problems with them. Problematic ones require ruled surface between 4 edges of a quadrangle with no paralel edges nor same direction.

Autocad has "edgesurf" or edgerule" tool which will do just that and might be my last facesaving resort. I hope to see improvments in this field soon.

[gregcashen]

Me too. :roll:

[Alek Sutulov]

I am puzzled why rulled surfaces are not available for roof structures if they are for curtain walls (haven't noticed the feature before Scott mentioned it). Seems to me,everything is in place programing wise .Someone forgot to turn the switch on?

[PeterJ]

BAM Construction used a similar roof in a house for Dennis Hopper sometime back in the early 90s. The house is in Venice Beach and the roof works nicely, it was done using a prefab rimber truss and clad in plywood which had enough twist to follow the curve.

No idea how they drew it mind....

[Alek Sutulov]

Here in Toronto, we have to factor for snow load and high winds. Also, in some areas there will be 9 feet overhang. No way to do it in wood.

[bclarch]

BAM Construction used a similar roof in a house for Dennis Hopper sometime back in the early 90s. The house is in Venice Beach and the roof works nicely, it was done using a prefab rimber truss and clad in plywood which had enough twist to follow the curve.

No idea how they drew it mind....

Check it out. Don't know if the diagonal boards visible in the ceiling photos are decorative or the actual structural decking. Decking would be my bet. Since the trusses are straight and appear to span from wall to wall, all that you would have to do is draw the profiles of the tops of the walls to get the undulations. Field supervision of the installation by the design architect strongly recommended. :shock: :D
http://www.bwk.tue.nl/fago/daylight/varbook/varianten_praktijk/S0main.html
http://www.arcspace.com/calif/buildoth/hopper.htm

[PeterJ]

That's the one alright. I remembered the boarding being ply, but clearly not. They are the deck I seem to remember that setting them on the diagonal gave a better drape. I think the roof is finished with a single ply membrane, presumably over insulation.

As to high levels of insulation, Brian Murphy the man behind BAM styles hmself an architect/builder so I suppose the two go hand in hand.

The project included a bath made of sheets of glass siliconed together which was rather fun, but better on his PII than mine.

[shaugh1784]

This might be an indication it's hard to build too. :wink: You better use multi layers of thin rigid insulation, because anything greater than 1" won't bend like that.

I wish you luck - do post pictures if it is built or modeled successfully.