Brick catenary arches

[Anonymous]

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/

[Dwight]

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.

[Hmooslechner]

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..)

[Anonymous]

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.

[Anonymous]

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!

[Hmooslechner]

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..

[Dwight]

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...

[Anonymous]

Interesting background there, Dwight.

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

[Aaron Bourgoin]

Gaudi told me he uses Autodesk Inventor and Revit.

[Dwight]

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