Barrel Vault SEO-no go

[Tom Krowka]

Have two barrel vaults intersecting. They are made from beam profiles, which is quick and easy. However, can't seem to get the SEO intersection quite right. Have attached a snapshot of the closest I can come; done with a substraction with downwards extrusion. Have tried every other operation, nothing seems to mitre the common angles as one would expect. The vaults are four inches thick, they have trim attached at the bottom as part of the profile.
Any comments?

[Erika Epstein]

Tom,
You threw out a challenge! Don't forget archicad is today's Lincoln Logs, Erector set etc. It was fun. Who knows, now we all might start doing barrel vaults.

You might also look at Ralph Wessel's Objective . It's only a couple of hundred dollars. If they have it you would also end up with a parametric object, easily edited as the design develops.

here

[rocorona]

Barry wrote:
It is in the standard library that came with the Australian flavour.
There is a section in the library called "Vaults 12".

I'm not sure if this is in the other national libraries.

We too, in Italy, have them. They are in the standard Graphisoft library, not in the extra one added from Cigraph (the local distributor)... I wonder if it can be freely posted here.

[Tom Krowka]

Can't find it in the US library......

[Ralph Wessel]

Tom wrote:
Have two barrel vaults intersecting. They are made from beam profiles, which is quick and easy. However, can't seem to get the SEO intersection quite right.

OBJECTiVE has been suggested as a possible solution (thanks Erika!) and I thought a few images might help illustrate how that works. Referring to the attached image:

• 1) Draw the required cross-section - OBJECTiVE will create a profiled object from this
  2) The profiled object can be cut up using OBJECTiVE's Split tool. Like ArchiCAD's Split, you simply trace a line where the object should be cut. The difference is that this will cut objects up in 3D.
  3) The offcut(s) can be dragged away or deleted as required.
  4) Repeatedly cutting the object (possibly from different orientations) can result in quite complex shapes. The profile can also be bent to a curve (horizontal or vertical).
  5) An example of the barrel vault you are trying to produce.

Look here for more information.

[Erika Epstein]

Tom,
In the AC8.1 subset library there is a cross vault.
HTH

[Erika Epstein]

Oh Ralph, how ill-timed my finding the 8.1 vault. I didn't see your post before I made mine.
Your solution though is excellent as always. Parametric, easy to edit and evolve with the design.

[Anonymous]

BTW: Here's a shot of one I did with profiled walls when this same question came up about a year and a half ago. The vaults are assembled with two halves meeting at the top. I'm pretty sure I used walls but beams should work as well.

[Ralph Wessel]

Erika wrote:
Oh Ralph, how ill-timed my finding the 8.1 vault. I didn't see your post before I made mine.
Your solution though is excellent as always. Parametric, easy to edit and evolve with the design.

No worries - if your post solves the problem, then it's the right answer. It comes down to the required level of detailing and complexity. The 8.1 vault (and many other objects) don't provide a lot of flexibility, but will be fine in simple cases.

[Karl Ottenstein]

The first method that I saw years ago for creating this type of cross vault was by David Nicholson-Cole as an object-making example (still in his Intro to Object Making book PDF - pages 30-31), requiring no GDL.

Basically, the concept is/was similar to those that Ralph uses with Objective, but the cutting is done with the polygonal marquee tool. The marquee-cut vault is viewed in 3D from the top, then save-as a new object which is then brought back in and multiplied around.

The nice advantage of Objective is that the cutting is live, with no extra object saving/etc, you have editable profiles, and many other options for shaping the result. Just slice and dice, as he illustrates.

Cheers,
Karl

PS Pages from Intro to Object Making attached, including copyright notice.... the entire PDF is available for download at various places, so I do not think this is a copyright violation...

[Tom Krowka]

Ralph:

Regarding your product and cutting tool in reference to the intersection of the two vaults: I think that would be the hardest part of the process. How would I be able to tell, in 3d, with a split tool, where the two vaults would intersect. It seems it would difficult to trace that line.

Am going to experiment some this afternoon.....