topic Re: Shell section in Modeling

Shell section

Anonymous — Tue, 23 May 2023 12:33:38 GMT

Hello,
I am working on a curved roof, and used an extruded shell to do it. Quite straight forward, drew the curved shape on plan extruded it with the shell tool, and then just positioned it on top of my building. But when I look at it in section (image attached) it is not a smooth curve as it should be but it appears faceted, composed of straight lines, which is also the way it appears in dwg once I save it for consultants that use AutoCAD, and, of course that is NOT the way it's supposed to be.
Is there any settings I'm missing, resolution of some sort?
Any suggestions highly appreciated, thank you.

Re: Shell section

Laszlo Nagy — Sun, 24 Nov 2013 22:21:03 GMT

Yes, the Shell is made up of segments.
I think the default segmentation setting is 36.
If you don't mind messing with the Registry you can change it.

I see you are on the Mac.
I can show you where to change it in Windows, and hopefully you will be able to figure out how to do it on the Mac.

In the Registry, go to the following place:

Computer\HKEY_CURRENT_USER\Software\GRAPHISOFT\ArchiCAD-64\ArchiCAD-64 17.0.0 INT R1\GSModeler.

Here change the value of ShellMaxSegmentationNumber from 36 to 72.
Also, change the value of ShellMinSegmentationNumber from 36 to 72.

Then Exit the Registry Editor.
Then exit ArchiCAD and restart it.
Go to your Section and regenerate it.
The Shell should now be generated with the newly specified segmentation, giving you a greater resolution.

Re: Shell section

Barry Kelly — Mon, 25 Nov 2013 00:34:39 GMT

But note this registry change will affect your machine only.
Anybody else opening the same file on another machine will have the shell revert back to what you originally had unless they make the registry change as well.
Barry.

Re: Shell section

Anonymous — Mon, 25 Nov 2013 21:18:28 GMT

Thank you for your replies.
I have to say that I think this is a MAJOR issue, a curved roof won't be represented as, well, curved. I honestly find it to be a huge, huge flaw. I guess I'll have to trace over the roof's cut section to be able to see it and print it the way it's meant to be.
I can already hear the client, "But, wasn't that supposed to be curved?, it looks awful this way!"
And me answering: "Yeah, no, well, the thing is, the software we use is not capable of showing the curved roof as a curve, but it will be curved in real life."

So professional.

Re: Shell section

Barry Kelly — Tue, 26 Nov 2013 01:21:39 GMT

Try using a complex profile wall or beam.
You will have much more control over the curve.
If you use a wall you wall have to be careful about what layer it is in, the layer priority and the strength (building material) of the complex profile because although you are using it as a roof it is really a wall and will interact (trim) with your other vertical walls.

Barry.

Re: Shell section

Anonymous — Thu, 28 Nov 2013 20:51:06 GMT

Barry, thank you.
Could you elaborate a bit on ur thoughts on how to accomplish this with complex profile wall? I want to give it a go...

Re: Shell section

Barry Kelly — Fri, 29 Nov 2013 03:21:47 GMT

Use you 'Profile Manager' to create a wall and/or beam profile using a fill with the desired shape and material.
Store it as a profile that you can use with the wall and/or beam tool.

Barry.

Re: Shell section

Barry Kelly — Fri, 29 Nov 2013 03:23:24 GMT

Then use Solid Element Operation to trim the walls below if need be.

Barry.

Re: Shell section

Anonymous — Fri, 29 Nov 2013 09:27:21 GMT

Just out of curiosity, isn't this setting also controlled by OPTIONS->MAGIC WAND SETTINGS and just adjust the segments settings accordingly?

Re: Shell section

Paul King — Mon, 16 Dec 2013 07:18:50 GMT

zeropointreference wrote:
Just out of curiosity, isn't this setting also controlled by OPTIONS->MAGIC WAND SETTINGS and just adjust the segments settings accordingly?

Doesn't make any difference for me....

Re: Shell section

Barry Kelly — Mon, 16 Dec 2013 07:28:12 GMT

The magic wand settings have no effect on the profile of a shell.
Barry.

Re: Shell section

DGSketcher — Tue, 18 Dec 2018 21:22:37 GMT

Thought I would update this as I am faced with the same issue as the OP.

It is possible to change the resolution for any shell arc to minimise the faceting, it will still be there but hopefully not so obvious that you have to explain the situation to the client. The solution is remarkably simple and as suggested earlier can be resolved with the Magic Wand settings. Simply draw the base line profile of your roof using lines, arcs, polylines. Change your Magic Wand settings as per the attached to provide enough faces to make the curve still look smooth on section. I have used 12 but you can use more or less to suit. Now select the shell tool with extrusion method and detailed input. Use spacebar + Rt-Click to trace the profile lines and specify the required extrusion length. You can then free rotate your roof into place and if required define the shell contour.

I am using AC22 but this should also work with earlier versions.

Re: Shell section

Lingwisyer — Wed, 19 Dec 2018 01:37:51 GMT

Does this actually increase the curve resolution of the arc, or convert the arc into straight segments? I have had times using other tools where the Magic Wand has broken up my single arc into smaller segments.

Ling.

Re: Shell section

DGSketcher — Wed, 19 Dec 2018 10:22:17 GMT

It does convert the arc into straight segments. So, as a consequence you loose the editable curve, but the appearance is as good as you would get if GS granted a resolution option in the tool. I do wish GS would update the shell tool so that we see smooth curves in sections etc, after all they do retain the original geometry which is displayed if you highlight the shell section, but for now it's a workaround that avoids the need to use elements with complex profiles or put up with crudely facetted arcs.

Re: Shell section

Erwin Edel — Wed, 19 Dec 2018 15:16:41 GMT

I suppose it depends on the radius of the arc, because 'traditional' round zinc dormers look fine when we draw the round part with shell tool. If I zoom in a lot (700%), I see the segments, sure, but when printed it looks fine.

Looks fine in artist impression too.

Re: Shell section

DGSketcher — Wed, 19 Dec 2018 16:12:40 GMT

I am looking at producing a curved roof. The attached shows how the default faceting manifests in a 120 degree arc with 3m radius above a 180 degree 600mm radius (dormer) at 1:20 at 100% zoom. Even at 1:50 it still looks like someone can't draw a smooth arc whereas the dormer looks a lot closer to what is expected.

Re: Shell section

runxel — Thu, 20 Dec 2018 17:12:43 GMT

This indeed a lack of Archicad.
The devs should look into it and convert this value from an absolute to an view relative one (if not abolishing it all).

If you make round profiles you have the same problem. It's not round at all!

Re: Shell section

Tim Ball — Thu, 20 Dec 2018 20:06:51 GMT

I also think this is controlled by magic wand settings, but you may have to remake the shell.

The complex profile is also a good idea if it works for you construction, but the nice thing about a shell is that you can pull and push the shape to amend as needed. Don’t forget you can apply a composite to a shell.

Re: Shell section

DGSketcher — Thu, 20 Dec 2018 22:38:54 GMT

Tim wrote:
I also think this is controlled by magic wand settings, but you may have to remake the shell.

The magic wand settings only apply when you click trace a 2D line profile on the floor plan. If you draw the profile directly as shown in the GS tutorial videos then arcs will default to the faceting shown in my image above.

Remaking the shell may be the biggest issue to using the magic wand method, particularly if your shell is full of holes & roof lights...