Shell shaped skylight

[sbrown]

Ok, its now time to put the massing / curtain system tools to a real world test. I need to make this skylight. I know revit made a shell shape back in 7. this one is an ellipse base(created with 4 arcs instead of elipse tool. Any suggestions on creating this?

[sbrown]

Isn't anyone up for this challenge?

[robert.manna]

Because I think you actually deserve a reply...

My first thought is to model the "mass" in your 3D program of choice, Rhino, Sketch-up, Microstation, Max, whatever... Then import either the dwg or sat file into the family editor, create a mass, throw it into your Revit project, and go from there. I actually have no idea if this will work or not.... And my organic modeling skills would need to be dusted off in order to even attempt to do a proof of concept test...

Hopefully someone else with a littler more experience in this regard will reply.

-R

[Andre Baros]

I've got a deadline this morning but I'll give it a shot at the end of the day. Seams like you just need the right equation for your mass instance components. I'd ask for dimensions, but if it isn't parametric, than it isn't worth it.

[sbrown]

Here is the size of the skylight. As for the height it will need to be parametric so I can play with the proportions. Do you think sketchup can model this? I don't have the other software mentioned.

[robert.manna]

My general feeling is that because sketch-up is so basic when you get down to it, lines & polygons defined by lines. You should be able to model just about anything you want (triangulated of course) but the question is, would you.... :)

Not much help I know.

What I don't fully understand about the form, is your first sketch made it appear to me at least that the shape is kinda of like a sweep along a spiral path, where the shape gets smaller as it spirals. It may be that you could do it with blends, etc, but it seems like an awful lot of work compared to the modeling ability of any number of other products out there, the real catch is getting a dwg or sat file that Revit is going to like... Doesn't 9.1 support importing nurb surfaces... ? or am I speaking out of turn...

-R

[greg.mcdowell]

Are the areas between the spirals curved in section or flat?

If they're curved then I can't think of any ways to do it without using sweeps but if they're flat then I would think you'd be able to create a series of concentric arcs at varying heights and use a Curtain System based on these lines to create the surface.

[robert.manna]

Are the areas between the spirals curved in section or flat?

If they're curved then I can't think of any ways to do it without using sweeps but if they're flat then I would think you'd be able to create a series of concentric arcs at varying heights and use a Curtain System based on these lines to create the surface.
He said "shell" so to me that means the only flat surface on that thing is each pane of glass. I think what we need to see is a couple of cross sections through it. The key is to understand the form that is desired, and the two plan sketches don't really fully convey the form. Also, While the final height doesn't really matter, even to attempt to make it parametric, one needs to understand the proportional relationships or "rules" desired by the designer.

-R

[dbaldacchino]

I'd like to give it a shot, but I agree...I cannot make out what the form is. It looks like a plan view so really, we could be actually looking at a "spherical" elliptical volume and the spiral is just the configuration of the mullion system. Am I on the right track? It could also be as suggested earlier that it's like a sweep of some curved form following a spiral, but if that's the case, you have a water draining nightmare on your hands between the spiral edges!

If it is an elliptical "sphere", I would start by doing a solid revolve....take one half of the plan form (the long side) and specify a rotation axis in the centerline of the plan form and rotate it 180 degrees. It should costruct like a half egg shape. But I don't want to go too far just in case I'm totally wrong on the form.

[sbrown]

The way I see it, the skylight is like a dome but it is rising / spiralling up to the center form. I see the "bands" as curved. I will try to draw a section.

I appreciate all the efforts.

[dbaldacchino]

Ok, so the half egg form is just an approximation. I'll have to think about this a bit because the sweep tool alone won't get you there since the path cannot curve up. And you cannot change the profile as you sweep it (that's what a loft tool does, right?) How about tricking the stair tool and use some custom railing profile to get the desired shape? I read somewhere on Augi about exporting the stair and re-importing into a massing family and then using the curtain system by face tool for some other modeling problem.

[robert.manna]

I read somewhere on Augi about exporting the stair and re-importing into a massing family and then using the curtain system by face tool for some other modeling problem.
It was a plain wall not, a curtain system, but doesn't really matter.

http://forums.augi.com/showthread.php?t=46568

Based on Scott's description, it sounds like what I was thinking, a "round' shape spiralling up to the top in the center. I can see the section in my head. Will try to jot it down and scan it. I will edit this post if I do.

-R

[Zoltan]

Well, It's not parametric by any means, since I modeled it in Rhino.

I made the spiral flat. If you tell me the height and the radius of the bulge, I can redo it quickly. I would attach the rvt, but it's 14MB!! I've attached the SAT as a zip file (we should really be able to attach SAT files to the forums).

[dbaldacchino]

Yep, you do have a water drainage nightmare with that configuration (note: I work in Houston and we are very flood-aware!), solvable through a maze of internal gutters :)

[greg.mcdowell]

I was thinking the curve in section might be one that allowed an area from above to drain on the one below, each one being more like a quarter circle than a half. That would solve the drainage problems... though you'd need quite a few additional horizontal members to encourage that shape (without using curved glass $$$$$)

[robert.manna]

I keep thinking of the advertisement that I used to see in Arch record for the Grand Old Opre and its huge glass dome....

-R

[robert.manna]

Ok, so here is the section I saw in my head when I saw the plan.

[Andre Baros]

Here's my progress so far. Still a few glitches to work out. Probably going to need some in-place family masses to make the ends work out...

Generic Mass family w/ instance parameters with a curtain system. Flexes pretty well, but it ain't pretty.

grin... this would be MUCH easier with a loft... it's elipses now but to get the stepping right it's going to have to become a series of blends... but at least it's all Revit so you can adjusted all you want and use it to drive the structure too.

[Andre Baros]

Revit Family so far... in case I don't get back to this fast enough for you, you should be able to work with this.

The file itself is too big to post, but just insert this family into a file, copy it a few times in place and then change the step value for each instance. Add a curtain system or a few and viola, blah, blah.

[sbrown]

Ok, so here is the section I saw in my head when I saw the plan.


You got it, awsome work guys. I dont' know the height yet. I went to the aquarium yesterday took a photo of the shell that I will base it on. Basically it needs to be a rectangular shape with a curved top that spirals up and gets narrower as it goes up. I'll post the pic. monday.

[Andre Baros]

A rectangular shape with a curved top is exactly what the last one I posted uses, but I've got much better version in the works so just ignore it. The family above steps between each segment, so it only spirals in plan, not section, I think I've got that figured out... but need time to draw it up.

[SCShell]

Hey there,
I don't get it....none of these look anything like me!

(Monday morning humor.)
Steve

[Dimitri Harvalias]

I thought of that on Friday but refrained from commenting :lol: . Coming from you it sounds better anyway Steve.
When Scott needs a guitar shaped skylight I'm sure you'll be the first guy he'll call.

Nice work by everyone on the skylight BTW. I love the collective brain trust and willingness to pitch in here. :beer:

[sbrown]

I do appreciate all the help. I look forward to seeing Andre's final solution. What he did will work for concept but its not very smooth. I'm afraid its not possible to model correctly in revit, however at release 7 or 8 they showed a shell building made with a massing family so I think it must be possible.

[robert.manna]

I do appreciate all the help. I look forward to seeing Andre's final solution. What he did will work for concept but its not very smooth. I'm afraid its not possible to model correctly in revit, however at release 7 or 8 they showed a shell building made with a massing family so I think it must be possible.
The building model you're talking about was done with a mass and curtain system(s) with pre-defined mullion spacing. I think (really just taking a guess) that Phil Read was responsible for it. If you want me to try and find out more I can, but it might take a day or two. I still think your best bet is going to be to have the mass modeled in a different program, I however confess to being not nearly as talented as others at using formulae to create mass shapes (I wish I had take some advanced geometry & calc courses in college :) ).

-R

[Scott D Davis]

I think Matt Jezyk created the shell shape for the release of 7.0....

[Andre Baros]

How important are the 4 arcs instead of ellipses to drive the shape? It's a lot harder to control the math with arcs than ellipses, because the centers go all over the place. (of course if the whole thing was circular it would be easy)

[sbrown]

You can use an ellipse and then I can match the walls to it below.

[Andre Baros]

It's kind of ugly right now, but it's getting close.

[dbaldacchino]

Nice! How are you controlling the elevation change in the sweep? Or is this being done outside of Revit?

[Andre Baros]

All Revit right now. Each section is an instance of the same family, with an equation to step it down. It's just that Revit won't let me add voids to sweeps created using ellipses so I have to find another way to trim the curves to just the visible portion before applying the curtain system.

[dbaldacchino]

Are those just masses? I thought that sweeps can only be horizontal....unless maybe you're controlling the slope of the path using ref lines, but the path is still planar?

If you can add solids (not sure if you're actually building this inside a generic model family or what), why couldn't you add voids? That sounds odd....never came across any limitation with regards to elliptical sweeps (never used them).

[Andre Baros]

The path of each sweep is indeed an inclined ellipse, sitting on a ref line (so that it flexes). I can cut the voids out if the whole thing is flat, but then there is no way to get each loop to meet the next smoothly. It probably doesn't help that the void is an ellipse too.

Here's some more updates, as you can see there is some problems at the top with the curtain system (those panels are several hundred feet tall, but Revit said that it was an error which could probably be ignored so I'm ignoring it for now) and the seam where the two sides meet.

The family is also included if someone else wants to work with it, sorry about the cryptic names, it's just faster to work that way and I'll clean that up at the end.

[Andre Baros]

Gotta call it a night. Here's a quick test just to see if it resolves when it's not all on top of itself. You could send this one in to support and say that your water slide family isn't cleaning up correctly and see if they'll add the features for you.

PS... it takes a while to refresh when you change the curtain grid spacing on this one.

[sbrown]

So why do you think the joint half way doesn't behave?

[Andre Baros]

Each curtain system starts at the "top" and each side has a slightly different "top".

[Andre Baros]

Do you still need this? I've got a new method started using curves instead of ellipses which seams to clean up better but isn't as easy to adjust. Revit just can't handle voids with ellipse based forms.

I'll give it a shot over the weekend if you still need it.

[sbrown]

I'm not sure if I'll need it or not. We are currently in budget talks and this skylight is close to the top of the list. So my guess is it will be a simpler spiral up with a flat top, probable a bigger gesture than the tight spiral with curves which is very expensive. I'll keep you posted. But your efforts aren't for nothing. I think its very important to show this to adsk so they know we really need to make this type of shape available.

[Andre Baros]

We'll for what it's worth, I can send you the final file. I found a mistake in the ellipse version, fixed it, and it works much better now. I'll post the family file up so that everyone can see it and play around with it. I agree that the factory needs to make this easier, and a loft tool would do the trick...though it would need banking control.

I'm surprised more people didn't take a crack at this, it's a good exercise in learning to build components, and I've already taken something I learned here and used it in a real project... real being one of ours not yours.

Here's a few more shots of the almost finished version... cleaning up the seam would require rebuilding the whole thing using curves instead of ellipses and loosing control over the plan shape of the spiral. There is one section of curtain system which came in upside down which I'm not going to solve anymore.

[sbrown]

Please send me the file(family or rvt.) pm me with your email and i'll give you access to an ftp site if the file is too big. This is great work!!!

[Andre Baros]

http://www.wkarch.com/Schematic/Shells/Revit-Shells.htm

Here's the file for anyone who wants to play with it. Actually pretty simple in the end though it would take some work to clean it up for construction. All the complications come from the way that Revit handles ellipses and sweeps. I'm also amazed at the file size, it's nearly 20megs with everything purged out... and it's not just the curtain system, it's the 6 mass elements which are only 250k separately.

If anyone is able to use this file or something from it, please let me know. It's seams pretty academic but it's lessons are pretty useful in many places.

[sbrown]

Any chance you made any of this in 9.0?

[Andre Baros]

Sorry. All 9.1.