topic Re: Brick catenary arches in Modeling

Brick catenary arches

Anonymous — Tue, 23 May 2023 14:31:29 GMT

Hi,

i've been reacquainting myself with Archicad after a few years of using other programs. After hearing about it's new shell and morph commands, i decided to give it another go. I'm currently doing my final year project where my structure basically consists of a series of large catenary arches, not too dissimilar from a brick viaduct. I would have normally modelled something like this on rhino/sketchup and the drafting in autocad but since time is tight, I thought I could kill two birds with one stone by using virtual building program such as Archicad. I was no expert using AC before so yet again I feel like a bit of a novice!

I have tried 2 different approaches to drawing the arches. The first was using the shell command and extruding a spline profile to form the arch, then lifting it upright and moving it into a straight brick wall of the same thickness. I then used the Trim Elements to Shell command to form the arch opening in the wall. http://postimg.org/image/tbbmjb8uf/
This seems relatively straightforward but my main problems is trying to align a brick texture to follow the line of the arch. I would maybe like to use the sketch renderer but cant get the proper textures on the arch.

The second approach was using the morph command. Again, I drew a spline, offset it, closed the profile and extruded it to form the arch morph object. I saved the morph in the library as a door but when applying it to a wall, the opening is the rectangular extent around the object and not the arch. Frustrating! The photo shows what i mean:

The morph allowed me to draw panels along the face of the arch, where I could apply textures individually and align them along the curve of the arch to some degree of accuracy. However, when trying a quick render, the textures were back at their default position as shown in the photos.

Sorry for the long message, I hope its clear what I am trying to achieve! Can anyone shed any light on this or maybe suggest a better way of drawing the arches? I also have Artlantis, is that a better way to apply textures? Any help would me much appreciated, I feel like i have wasted a lot time trying to get this and deadlines are fast approaching!
http://postimg.org/image/d61sa05mb/
http://postimg.org/image/vrkkl5a0h/

Re: Brick catenary arches

Dwight — Tue, 09 Apr 2013 21:31:37 GMT

You won't get precise texture mapping on shells, morphs or any distorted surfaces since Archicad is poor with UV challenges.

I suggest that you actually model your brickwork on the arch sides and use texture mapping only on walls above. Achieve this by making a complex profile fill of the individual tapered blocks arranged in the complex profile editing window. Use this fill to define a beam drawn across rather than along the span.

Re: Brick catenary arches

Hmooslechner — Wed, 10 Apr 2013 17:07:33 GMT

i recently programmed a window-library Part for arches - round and segment.

You can download it in Archicad by opening the window-tool - and left obove You type in: "Fensteröffnung Bogen 16 inkl Bogenmauerwerke" - and let it search in the Bim-Server.

Then You can put in this library-part in Your wall.
You can drag the startpoint of the Arch . the numbers of needet bricks ares calculatet.

little Video-Tut..

youtu.be/ILYAOOybUCc
(dont mention my "englisch to runaway" - i am still learning..for the rest of my live..)

Re: Brick catenary arches

Anonymous — Wed, 10 Apr 2013 18:56:21 GMT

Dwight wrote:
You won't get precise texture mapping on shells, morphs or any distorted surfaces since Archicad is poor with UV challenges.

I suggest that you actually model your brickwork on the arch sides and use texture mapping only on walls above. Achieve this by making a complex profile fill of the individual tapered blocks arranged in the complex profile editing window. Use this fill to define a beam drawn across rather than along the span.

Thanks for your help Dwight, that worked well! Do you have any suggestions on how I could possibly map a texture on the face of the arch? Would I better off using something like Artlantis?

Incidentally, when using Lightworks engine, the texture is aligned how I want it to be but that was by using the morph method to create the arch.

Re: Brick catenary arches

Anonymous — Wed, 10 Apr 2013 19:27:53 GMT

Danke Heimo!

That's a really great custom element. I just watched your video and will experiment a little!

Unfortunately i'm looking to do a catenary (Kettenlinie?) arch and I think yours is strictly semi-circular? Maybe I should change my design because yours works really well!

Re: Brick catenary arches

Hmooslechner — Wed, 10 Apr 2013 20:50:21 GMT

The matehmatics of an catenary (Kettenlinie?) is still too complicated for me ( i thoght about ropes - thats mathematicly just the other way round).

If it would be possible for me to calculate exact differences on a hyperbolic curve this would be nearest to it i think. But that takes till july and august, when i will have more Time.. Its just a hobby now..

Re: Brick catenary arches

Dwight — Wed, 10 Apr 2013 20:51:36 GMT

Artlantis does have more mapping options and easy visual adjustment for textures, but I am always nervous when it comes to mapping masonry.

BTW: For LightWorks rendering, you'll want to call up a special procedural surface, not the default brick. See attached for the path "Load from Archive" and then set the shader - it gives you choices as to the brick arrangement flawlessly.

But why not model each brick?

Then you have perfect control. [You array brick-shaped fills on the elevation of your arch and copy the fills to the complex profile windo...

Re: Brick catenary arches

Anonymous — Wed, 10 Apr 2013 20:57:16 GMT

Interesting background there, Dwight.

Edit: comment now irrelevant. Let's just say Dwight beat the censor

Re: Brick catenary arches

Aaron Bourgoin — Wed, 10 Apr 2013 21:47:53 GMT

Gaudi told me he uses Autodesk Inventor and Revit.

Re: Brick catenary arches

Dwight — Wed, 10 Apr 2013 22:11:10 GMT

And here is the little-leather-sag-bag method for catenary generation from Gaudi's Sagrada Familia exhibition.

Re: Brick catenary arches

Anonymous — Thu, 11 Apr 2013 00:03:59 GMT

Thanks Dwight,

it took me a while to model the arch as you described but it looks well. The only problem now is a noticeable drain on my memory and processor when placing them due to their size and complexity. Considering i'm using dozens of these in my building i might be selective and only use them in my renders and use the plain flat edged arches everywhere else.

Hmooslechner wrote:
The matehmatics of an catenary (Kettenlinie?) is still too complicated for me ( i thoght about ropes - thats mathematicly just the other way round).

If it would be possible for me to calculate exact differences on a hyperbolic curve this would be nearest to it i think. But that takes till july and august, when i will have more Time.. Its just a hobby now..

No problem Heino, i wasn't expecting you to draw up a catenary straightaway! thanks

Re: Brick catenary arches

Dwight — Thu, 11 Apr 2013 00:20:40 GMT

You've modeled the individual brick units, now go back and model the grout as a simple, single block. Put the brick arches in a special layer toggled as needed, swapping the basic form defined by the grout blob for routine views.

You can also render the flat face of the arch and use that as your hi-res texture map. Use the 3D Align tool to make it fit.

As to math, the catenary is defined by: y = (cosh(1) - 1) x 2 + 1 so Mooseman should have no problem fitting that into a twelve line GDL script. [joke].

Re: Brick catenary arches

Anonymous — Sun, 14 Apr 2013 13:05:55 GMT

Dwight wrote:

You can also render the flat face of the arch and use that as your hi-res texture map. Use the 3D Align tool to make it fit.

This seems like a good solution as it wouldn't drain my resources. I've rendered the face of the arch. How do i apply the custom texture to the arch? I've looked around a bit but can't find a solution. Do I customise the GDL scripting? (I wouldn't be too comfortable doing that!)

Re: Brick catenary arches

Dwight — Sun, 14 Apr 2013 17:17:46 GMT

Use the image as a material texture. Apply the material. Align it using the 3D Align tool. Viola!

Re: Brick catenary arches

Anonymous — Sun, 14 Apr 2013 21:21:30 GMT

I've applied the material but for some reason can't align the texture.

Am I right in selecting the element then Design>Align 3D Texture>Set Direction? When I do this, it asks me to click on the main surface of the selected element, which I do and then nothing happens.

Sorry if i missed something really obvious!

Re: Brick catenary arches

Dwight — Sun, 14 Apr 2013 21:29:51 GMT

So you aren't left hanging on Sunday night, I'll investigate and post a reply soonest. You'l be helping me defer some difficult design decisions on another project so that I'll run out of time to dither around trying to make a better solution.

Re: Brick catenary arches

Anonymous — Sun, 14 Apr 2013 21:37:15 GMT

No worries Dwight, take your time! I can work away for the time being on the rest of the project, this is only for when I come to rendering it at some stage.

I appreciate your help!

Re: Brick catenary arches

Dwight — Sun, 14 Apr 2013 22:00:28 GMT

I've duplicated the condition and find no problem mapping or aligning to the side of a complex profile arch. So i think your mousecraft needs work. You've got to hit a place on the material surface - a node is best - to change the alignment. Also know your exact size since the mapping assumes 1.000.

Another way to do this is to make your object surface start at the origin - where all object mapping also originates.

Re: Brick catenary arches

David Maudlin — Mon, 15 Apr 2013 12:02:00 GMT

trunmaster wrote:
Am I right in selecting the element then Design>Align 3D Texture>Set Direction? When I do this, it asks me to click on the main surface of the selected element, which I do and then nothing happens.

I think you want to Set Origin, not Set Direction.

David

Re: Brick catenary arches

Anonymous — Mon, 15 Apr 2013 18:04:44 GMT

I have set the origin already. I think I have it now, I just cropped the rendered image of the arch to make sure the origin would begin right at the base of the arch. The new arch texture does not appear in the sketch renderer but I can render the previous custom arch with the individual bricks for that if I need.

Thank you all for your help!