Curved + Diagonal Curtain System

[Grumple]

Hi all,

I am again playing with something far beyond my capabilities!

What I'm trying to do is...

Create an oval shaped building (The 'Gherkin' in London), which has a diagonal sweeping curtain system.

Basically, I've created a mass of the building shape...
I can get a curtain system on there no problem, but when it comes to slanting it at an angle, it just does nothing.

Normal procedure is to place the system, click the little window symbol and enter different alignment angles... This works fine when I create a system on a flat mass, but it just does nothing on my curved mass.


Might be interesting to see the different ways you Revit Gurus would do this : )

Any input much apreciated,
Cheers

[Grumple]

Someone has built a very good 3ds Max model of it:

http://www.exchange3d.com/cubecart/architecture/gherkin-building-london-uk-/prod_882.html

I'm not expecting to get anywhere near that quality, but it'd be good to know how to go about something like that in Revit.

[twiceroadsfool]

Your best bet would be to segment the mass, so that when you apply the curtain system to it, the boundary of piece edge of the system fell on the segment of a mass that represented those mullions. Otherwise im not sure youll be able to do it...

[mthurnauer]

I have a fiar amount of experience with doing this type of curtainwall. How you intend of having the curtainwall actually constructed with determine how to model it. I have attached two sketches that show how the geometry can be created. In both versions, it is important that you generate a clean layout for the curtainwall. You will want to make sure that the total perimeter length and the individual arc lengths of each radius are divisible by the same segment length. Each radius also needs to be co-tangent. Getting this worked out is critical to making a skin that is clean. Once you have established the work points, there are two ways to create the geometry. The first option which is the easier solution is that the geometry is facetted vertically at every work point. There is either a vertical mullion at the facets or a silicone butt joint (a mullion is preferred.) You then have diagonal mullions which receive an exterior snap cap with a profile of your choice. With a tinted glazing, the system will appear from the exterior to be all diagonal mullions, but from the interior it would have both vertical and diagonal mullions. The second option is that the geometry is facetted by connecting points on a diagonal, creating triangular flat planes. This is more challenging, but if you work out the initial geometry as I initially stated, you can do it either way. This option will be easier to model in another program and then import as a mass object. You can then create curtainwall from each face of the mass.When you apply the mullions to the perimeter of the triangular face, it will be difficult to get the mullion oriented properly. You will also have to look at the proper mullion type to handle the angle of the glazing to the mullion. Most curtainwall manufacturers will allow a 3 degree angle between the face of the glazing and the mullion before you will be required to use an adjustable splayed mullion. This is important because splayed mullions are more bulky and not as elegant.

[AP23]

Unfortunately, custom curtain panels in Revit can’t be applied on curved and skewed surfaces. In theory, you can do the two methods mentioned by mthurnauer and ad an angle parameter in elevation and in section. This enables the custom curtain panel to tilt and skew at the same time while the curtain wall/ system layout is orthogonal. I haven’t tried it out, but I can imagine it would be extremely cumbersome to figure all the angles for each panel out. So the only thing left to do is to create the whole curtain system including the mullions in any other software and import it in Revit.

Here is an example of a curtain system that was done in 3ds max and the rest in Revit. This firm won the Revit BIM Experience Awards.

http://www.bdcnetwork.com/article/CA6602566.html

[twiceroadsfool]

<paris> "Thats hawt." </paris>

[mthurnauer]

If you use method one, it is actually quite easy to construct. Attached are a few video tutorials. Sorry that there is no sound:

This first one shows making a custom curtainwall panel that has a mullion embeded in it for the diagonal. The panel will flex with changes in the curtainwall:

http://www.screencast.com/users/mthurnauer/folders/Default/media/f045ad93-1e4a-4b57-b1ae-a65e635c8eb2

This continues from the first showing the application of the curtainwall panel:

http://www.screencast.com/users/mthurnauer/folders/Jing/media/5ed7d76b-04e2-4182-9f99-c8b653c55695

[mthurnauer]

here is rendered image

[Grumple]

That makes it look much too easy mthurnauer! - I've had a look at doing it like this, and I can't see how this would be possible on 'slanted' glass...

I really want to learn how to use Max, but just don't have the time.. I wouldn't know where to start!

How do you 'segment' a mass? I was trying to work out how to just draw on it, but to no avail...

I've attached the mass shape of the building if anyone wants to have a play.

Thanks for all the input, very interesting as always : )

[mthurnauer]

What I mean by segmented is that it would be better if the geometry were not smooth. For example, your shape is a true circle in plan, a segmented shape (or properly named facetted) as a 2d element is made up of a series of segments or a series of faces as 3d solid. You could make this in Revit. If you draw the profile in section as a series of segments along the profile and then extrude it in lieu of revolving it, you will get what you need to generate your curtainwall. This would still be easier done in other applications though.

[mthurnauer]

I will take a stab at showing you how to do it. I am going to make the assumption that the building will be facetted vertically at each floor line. What would be the floor to floor?

[Grumple]

I see what you mean about it being smooth... I was just getting the basic shape down before I let revit work the rest out!

The building is 180m tall and floor to ceiling height is 2.75m with 150mm floor thickness

So floor to floor would be about 2.9m

Thanks for all your input : )

[mthurnauer]

I managed to figure out how to do this purely inside revit and I will tell you that it was tricky, but fun. I made a mass family that is a blend and the top and bottom shapes are a polygons with the top shape rotated so that its vertexes align with the midpoints of the bottom. I established shared parameters for the top radius and bottom radius. I loaded the mass into your project and then created a mass schedule. In the schedule, you can input the radius at each floor level which I obtained by measuring your mass.

[mthurnauer]

Here is a rendering of the model

[cipa11]

yes, the 3ds model is made by arched segments (spiral sweeps) expensier...and yours can be pre-cut with easy in factory; so cheaper. Congrats! One thing maybe.... the original has 2 slices every floor...so, you have to rotate the second and ch. parameters in schedule. not a big deal.

[Grumple]

Awesome job! : )

I just have a few questions...

What shared parameters did you make for the top and bottom of the blended mass? Because they're polygons I can't use a radius dimension...

How did you achieve the diamond pattern of glass??? Was your mass made of 2 floor height blends - 1 going clockwise and 1 anti-clockwise?

Great job, I just need to learn how to do it now!

[mthurnauer]

Jay,
I made a mass family and used a polygon shape for the top and bottom. You can set the number of sides and draw these to a specific radius, but unfortunately once you have drawn the shape, it is just a series of individual segments and the radius of the shape is not parametric. To solve this, you have to put a dimension from the center to each and every segment and then make a parameter for the radius. I did this for the top and made a Top radius and made a incident parameter for it. I then copied the sketch and dimensions and then edited the bottom and pasted it in. I selected all of the dimensions and made a new parameter for the bottom radius. I then rotated the sketch of the bottom so that the vertexes of one sketch align with the midpoints of the other sketch. You then have to edit the vertex connections to triangulate the mass properly. Next, I made an incident parameter for the height. I loaded the mass family into the project and placed it on level 0. I then copied the mass to every floor. It is important that you make the radius and height parameters of the mass family shared parameters and add them to your project parameters. I then made a mass schedule and then modified the top and bottom radius at each floor; the top radius of one level matches the bottom radius of the floor above. To make the model truly a diagrid, you need to select the mass on every other floor and rotate it so that the vertex aligns with the midpoint of the level below. This gives you the final mass for the building. I then generated a curtainwall from the exterior faces of the mass on every floor. I realize now that it would have been better to do that step before copying the mass to every level.

Doing this exercise highlighted something that I think should be a new feature that I will add to my wish list. It would be a great improvement to be able to draw any curved shape, be it a circle, ellipse, or arc, and set it to be segmented by either a max. segment length or number of segments and yet remain parametric as a curve. One of the limitations I encountered was that there is a limitation to the number of sides you can have for a polygon shape (3 to 36). If I needed to exceed 36 sides, I would have had to spend much more time working out the geometry by doing a radial array for mt initial shape.

[Grumple]

Hi,

Thanks for explaining all that!

It makes a lot more sense now - I've had a good play but for some reason it won't allow the radius parameters to be changed/flexed...

I create the bottom polygon and dimension from each face to the intersection of the reference lines in the ref level plan view of generic mass template - then add the shared parameter 'Bottom radius'

When I try to test this and change the parameter value in 'Family types' it won't allow it because it breaks constraints. I think the constraints are of the dimensions to the reference lines used to make them (not entirely sure because it won't find a view to show me properly)...

I also tried this using 'Bottom diameter' instead (taking out the reference lines and dimensioning across from face to face) - but it still won't allow the parameter to be changed...

Am I missing something?

[mthurnauer]

The best I can explain the problem is that if all you have are the original two reference planes, their 'gravity' throws things off. You need to have a reference plane that intersects the midpoint of each segment, then dimension from the segment to the center and it should work. I attached the family I made. Note that these are shared parameters which you will need to add to your parameter file and also load into your project under masses.

[Calvn_Swing]

I believe we have another Phil Read in the house... Anyone else want to call it?

Fantastic job! We're about to undergo a kooky project of our own. I may be PMing you a bit. Very nicely done.

(Edit: Yikes, talk about a case of mistaken identity - or exhausted brain fart... No offense to Paul Aubin, but he wasn't who I intended to reference. Thanks to Steve for catching me on that one... can we say embarrassing?)

[twiceroadsfool]

Beautifully done!

Kelly, what kind of Kooky? Im a little bored at home, hahahaha.... :-)

[Grumple]

That worked : )

Thought it must be those pesky origional ref planes...

One thing I can't work out though - Why is your mass's face segmented (faceted?) into triangles??? = /\/\/\/\/\/\/\

Mine has just angled the vertical lines slightly = \ \ \ \ \ \ \ \ \


Thanks for all your help, it's given me a good idea of how problems can be worked out.

[scj.schulz]

Don`t know anything about REVIT, but in full blown AutoCAD free-formed surfaces can be made and developed using the programs from
www.ant-ares.de
Regards
Jochen

[mthurnauer]

Jay,
To get it to triangulate depends on how you connect the vertexes. Take a look at the vertex connection in family I posted. The upper shape is rotated from the bottom and then only one of the two vertex handles per node is connected. I figured it out by trial and error. It did not work as I anticipated.

[Grumple]

The upper shape is rotated from the bottom and then only one of the two vertex handles per node is connected.

At the risk of sounding even more retarded...

Vertex handles per node? : |

I'm not sure how to explore your family this in depth... In family editor I can either see it complete with 2 handles to move it up or down, or edit top/bottom to see the polygons. In a project it is just 1 complete mass object that highlights as 1 unit...


Thanks for all the input : )

[Andre Carvalho]

At the risk of sounding even more retarded...

Vertex handles per node? : |

I'm not sure how to explore your family this in depth... In family editor I can either see it complete with 2 handles to move it up or down, or edit top/bottom to see the polygons. In a project it is just 1 complete mass object that highlights as 1 unit...


Thanks for all the input : )

In the family editor, when you select the geometry and edit it, you will notice an option (at the left) to change the way vertex are connected. Revit will show the vertex and lines with blue dots or empty dots to show the options to connect the vertex.

Andre Carvalho

[mthurnauer]

This question challenged me to see if I could create a diagrid that we did on a past project that is probably one of the most complex precast concrete buildings in the US. The skin is made up of about 500 precast pieces of over 140 different shapes. I originally modeled it with another application and the form manufacturer used the 3d model to make the forms. Unfortunately, the model I created was not parametric so if any dimensions changed to the exterior, I had to scrap a lot of pieces and start from scratch. I tried to see if I could create these panels in Revit and make them fully parametric. I am pretty close; it works for tighter radius panels, but when they become almost flat I get an error. My OCD is keeping me from quitting on this problem. Attached is the finished building and a snapshot of the model at the nose of the building.

[Grumple]

Thanks for that Andre... I wan't aware of that tool

Nice building mthurnauer - Let us know when you manage to Revit it : )


My own 'Gherkin' (oo er) is on hold atm... I've realised a way of complicating it even more that I just don't have the time to attack yet

[AP23]

This question challenged me to see if I could create a diagrid that we did on a past project that is probably one of the most complex precast concrete buildings in the US. The skin is made up of about 500 precast pieces of over 140 different shapes. I originally modeled it with another application and the form manufacturer used the 3d model to make the forms. Unfortunately, the model I created was not parametric so if any dimensions changed to the exterior, I had to scrap a lot of pieces and start from scratch. I tried to see if I could create these panels in Revit and make them fully parametric. I am pretty close; it works for tighter radius panels, but when they become almost flat I get an error. My OCD is keeping me from quitting on this problem. Attached is the finished building and a snapshot of the model at the nose of the building.

Are you using generic model family for precast concrete pieces? And how do you get them in place?