Help needed with circular beams and 'free-form' shape.

[Anonymous]

Hello,

So I'm trying to create a steel structure (concept) that can be bent on plan (so it's basically stretchable)

A precedent to what I'm trying to create can be found here: Image

I've used OBJECTiVE for a less complicated form but it needs developing. I can't seem to find a way of altering the shape in plan whilst also retaining it's vertical height etc.

I've attached what I have already achieved, by using the regular profile and OBJECTiVE, but all the arcs need to be joined together (and the from needs changing) (Also, my file is extremely slow since placing these arcs, is there a way to speed it up?)

As you can see from the attachment below, in plan the existing arcs are straight lines at various angles. I want to be able to bend the profile in plan. (the height of each curve can be determined in elevation).

[/img]Exsisting Plan


The beam and magic want do not work unfortunately. The profile needs to be able to "stretch"... I should also add that the total length of this singular piece of steel will be around 80 metres. (though I can cut it and join it together if there is a limit in terms of length.)


Image

Thank You very much, Hopefully such a task can be carried out... ArchiCAD 15 looks like it can do this but my deadline is next week!

[Anonymous]

Steve wrote:
Thanks for sharing your project. I think it's cool.
As for how to make those pipes. Hmm...
That will be a bit of a challenge. Especially if it needs to be dimensionable, manufacturable, and constructible. I hope you will post the solution.

I have in mind a few things I will try but I don't expect to be able to do it very well.

Have you tried using the Spiral object in the Basic Shapes library folder?

This was easy using complex profile and some spirals of same dia.

The image has changed!

How did you create that? Could I use the magic wand on a polyline for example? Is it editable in plan too?

Thank you

[NCornia]

Yes, Steve, please show that is very interesting and I have found that there is very little information about the Spiral object, especially as you have manipulated it.

[Steve Jepson]

Part of it is a round Complex Profile drawn as a wall using the magic wand on a spline.
I attached a few Spirals to it. Three I think. The Spiral object can be configured to rotate in any angel and the spiral can be any height or twist. Set the spiral to 600 or so and stretch it around in 3d to get what you want.

This was arranged some in 2d but mostly made in 3d. You can't manipulate it very well but I can get it to do approximately what I want.

It's not nearly as easy as Objective or the other Tube add-on. Those would be great to have. Too bad they don't come with ArchiCAD.
It cost me so much to keep upgrading for stuff I don't need that I can't afford to buy the add-ons I want. Oh well. I don't have much call for designing free form tubes or free form anything for that matter.
Just for fun.

It am confident that I could model the example if I were given some control points to work with. Height, diameter, length, number of twists.

If I were making it, it would be constructible with regular pipe fittings as far as possible and with dimensions for radius that can be located and are useable.
I don't mind things that look free-form, but I can't bring my self to make anything that has no control on fabrication.

[NCornia]

Thanks Steve. That is a good rundown.

I also wish that Objective were part of ArchiCAD. There are so many great add-ons, and so many moths flying out of the wallet. If Graphisoft were to integrate just a few of the great add-ons out there, they could call that a new release, and you would see people rushing to upgrade. It would be interesting to do the math and compare an add-on maker's revenue increase or decrease if they were to sell to Graphisoft. I imagine they have and don't see a benefit of doing so.

On the flip side ArchiCAD's openess and powerful GDL script allows for such innovation that might not come from the inside. This is a wonderful aspect of the software. But then there are those moths in the wallet again. Catch 22 anyone?

On your last point, I think one of the future promises of 3D software is that you wouldn't necessarily have to worry about constructability (except from a structural safety and load bearing pov) when designing in 3D. as machining equipment and technology advances you should be able to generate any reasonable geometry and a machine will fabricate it as created in the software. They are already doing this with 3D printers and some parts are even usable in cars, construction, etc.

Anyway, sorry for the rant. And I haven't even had any coffee in weeks. Maybe I need a fix now.

[Anonymous]

Olivier wrote:
You can try 3D Tubing object in the library below (Tubes folder).

Follow insrtructions, and you will be able to do any path for a tube, in 3D window.
Work in wireframe mode with the lowest resolution (4), and check 3D Axis On.
A resolution of 12 is good enough for a rendering and a decent Polycount.

How do I check 3D Axis on? I've searched for it (in Mac you can search for any tool etc. and it points you in the right direction), however never came up! Nor has the forum matched "3D Axis"

Thank You

... I'm experimenting with 3 different tools!

[Anonymous]

See attached screenshot.

3D Axes "On", and set 3D window in wireframe mode .
Colored arrows indicate the various functions of graphical hotspots.

This is not an add-on, just a free libray part.
Not so powerfull than Objective, but it can help to build twisted tubes.
There is another object for rectangular cross section.

[Steve Jepson]

Love it. What versions of ArchiCAD doses it work with ?

[Ralph Wessel]

NStocks wrote:
How did you get each piece to join up so neatly? Would it be just as easy to join a circular profile?
P.S How long is the continuos strip that was previously posted?

The model would work in exactly the same way irrespective of the profile shape. In this case, it was actually a custom profile (the underside is recessed for the fixing detail) and is about 7m long in total. This model was done to a very high level of accuracy because the components were manufactured directly from the model.

There are 2 important points to keep in mind if you want profiles to meet cleanly:

• 1. Ideally, try to ensure that transitions between curves meet at a tangent to both curves. At the very least, use the twisting parameters to ensure the profile ends are at the same orientation where they meet.
  
  2. If the profiles don't cleanly meet, extend their ends (using the start/end offset values in the OBJECTiVE tool settings) so they deliberately and completely overlap. Then use the tool OBJECTiVE > Tools > Split to cut the profiles at the junction point so they join cleanly.

[Anonymous]

Here's a 10 minute attempt at using OBJECTiVE and the 3D tube.

Both tools will do the job just fine which is what my main concern was. I will probably use OBJECTiVE because I find it to be more flexible. i.e the 3D tube has straight tubes that must remain straight on the Y xis.

It will take a while to execute accurately but I have patience at these sort of things!

The image below: The red tube is the 3D tube and the white tube is OBJECTiVE (though I haven't spent much time on it so it's not very neat yet).

Tubes

The 2nd image is what the 'outline' of the shape (though it won't be this thick) and it will have around 12 different points on the Y axis. this was created with a complex profile, a spline and wall tool.

http://dl.dropbox.com/u/1055166/outline.png

Thank you to all who has helped me out with this. As always I'm excited to see what the final outcome is

P.S I have a 'pattern' or strategy for this form, it's not simply random. (well perhaps one could say the spline is random but it's basically a stretched line...)

[Steve Jepson]

Have you tried the MEP Flexible Duct 14 ?