topic Re: How do I model this U-stair? in Modeling

How do I model this U-stair?

Mats_Knutsson — Tue, 22 Jul 2025 10:15:38 GMT

Hi,
Preferably in one object and it needs to align to the figure. The middle "landing" part is causing me problems I cant solve.
Br,
Mats

Re: How do I model this U-stair?

Hmooslechner — Wed, 23 Dec 2020 06:50:34 GMT

I can't - do it in one part. Its possible in 2 parts, but not in one single part. Doing in 2 parts is still very difficult.

Can You?

Graphisoft !! - make such things possible in an easy way without the need of workarounds! There are many posts at this topic - think about it to make it really easy to construct every stair the easiest way possible for the user! Its much too time-consuming now. The stair-Tool is realy just "a baby" of the real needed stair-tool it could be! Develop it to "grown up" status!

Re: How do I model this U-stair?

Dontknow — Wed, 23 Dec 2020 10:44:14 GMT

Do you mean in exactly the same shape as you drawn it, with the big stair step in the middle?

Re: How do I model this U-stair?

Mats_Knutsson — Sat, 26 Dec 2020 14:14:53 GMT

Dontknow wrote:
Do you mean in exactly the same shape as you drawn it, with the big stair step in the middle?

yep.
The 2D is from a web service provided by the stair manufacturer.

Re: How do I model this U-stair?

Dontknow — Sat, 26 Dec 2020 18:14:59 GMT

The stairshape is no problem for ArchiCad but the big stair step is the problem.

In this case I would model the stair myself.
Using walls, slabs, columns and morphs.

I once made my own spiral stair excisting out of columns, slabs, morphs and a spiral from the library:

And a stair for a perfect 3D impression:

Re: How do I model this U-stair?

Emre Senoglu — Sat, 26 Dec 2020 18:43:58 GMT

hey so i've managed to do this - it's a pretty lame method of doing it, but it is possible. don't want to sound vain, but i am pretty proud about this achievement, seeing as even heimo hasn't found a way

basically, you hide risers and adjust the treads to the thickness of the riser height. you can then manually adjust the shape of the treads. the versions i made are a bit crude, but with a bit of fine tuning i'm sure you can make it look nicer. i have to agree with heimo though - this is a very strange way of doing it, and there should be a simpler way.

here a video showing how: https://www.loom.com/share/c8e177d007f74c9583612e4823454cf2
let me know if there are any unclear parts!

Re: How do I model this U-stair?

Laszlo Nagy — Sun, 27 Dec 2020 14:20:42 GMT

Imre, yes, this is possible to do, the reason I did not suggest this solution myself earlier is that in this case, you can only adjust the geometry of the Treads and Risers, but not the STRUCTURE of the Stair itself. So, if you cut a section through the middle landing and the modified winder Treads, you will see that the structure was not modified. And that is a problem. In some cases, it causes the Structure to protrude from below the modified Tread/Riser geometry.

I am starting to think the solution here would be for the Stair Tool to let you actually customize your stair winders like the old Stair Tool did, letting you define the location of the points where the winders converged and stuff like that. Or, let you draw the exact desired floor plan layout of the Treads/Risers and generate the Stair geometry based on that (there used to be a separate command for that).
You know, some solution that would enable you to achieve any winder geometry for both Treads/Risers and Structure you wish to achieve.

Re: How do I model this U-stair?

runxel — Mon, 28 Dec 2020 17:17:32 GMT

The best I could do rn.

Not that great, tbh.
The main problem is of course that we can't alter landings and going directly and intuitively.
Also the stair tool is way to picky and as soon something is just tiny bit different then the boring default stair, you run into troubles. Also it always falls to back to "same angles" as winding method. Urgh.

Re: How do I model this U-stair?

Hmooslechner — Fri, 01 Jan 2021 11:05:18 GMT

It is - of course - always possible to make such a stair with the morph-Tool from scratch. Its just real work and time-consuming. But whats about the stair-tool, which cant make this really (should be-) easy-task without big efforts?
Shall i make a morph-construction-Video for this stair?

Re: How do I model this U-stair?

Mats_Knutsson — Fri, 01 Jan 2021 20:05:47 GMT

Hmooslechner wrote:
It is - of course - always possible to make such a stair with the morph-Tool from scratch. Its just real work and time-consuming. But whats about the stair-tool, which cant make this really (should be-) easy-task without big efforts?
Shall i make a morph-construction-Video for this stair?

It would be interesting to see how you solve the underside with a morph. I guess a couple of SEO's!? Anyway it's kind of embarrasing that the stair can do loads of stairs that I can't use.

Re: How do I model this U-stair?

Hmooslechner — Sat, 02 Jan 2021 20:06:23 GMT

something like this: Huge amount of mouse-clicks but doable..

On my old macbookpro, filming something like this is very near the performance-limit and therefore its possible to make some mis-mouse-clicks and so there seems to be some minimal uncorrect points that caused the end-problem, but the way would be possible.

later i found the glitch:

Re: How do I model this U-stair?

Hmooslechner — Thu, 07 Jan 2021 05:41:42 GMT

I really do like solving questions like this, its my "hobby" to look for solutions in dead-ends, kind of crossword-puzzle-feeling but with the benefit to other people and for raising my own knowledge.. Thanks for such questions.

It should be clear, that graphisoft has to work on better solutions here with its Stairtool. It was a really good BEGINNING, but it has to be made much better! Not dead ends! Something like a dialoguebox with the message - there is no solution for this geometry - should never appear on the eyes of the user.

Now - this tool is just the half way..

Re: How do I model this U-stair?

Hmooslechner — Thu, 07 Jan 2021 16:32:56 GMT

another Workflow:

Re: How do I model this U-stair?

Mats_Knutsson — Fri, 08 Jan 2021 07:53:56 GMT

Hmooslechner wrote:
another Workflow:

You've got the stair craze . Nice work. I figure the negative volume ca be done by using the terrain tool. I haven't had time to even open the project yet but hopefully next week.