Modeling
About Archicad's design tools, element connections, modeling concepts, etc.

roof bug AC11? 1200 and previous

Eduardo Rolon
Moderator
I don't know if this was posted before, happens in Mac intels and PPC and it is not fixed in todays update.

Create a roof specify the angle and thickness…
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

20 REPLIES 20
Eduardo Rolon
Moderator
After drawing the roof, change the angle if you tab to the thickness you'll see that AC has decided that the roof thickness cannot stay as was specified and it will make it thicker.

If you don't press Tab and just hit ok then you will find the new thickness when you do a section thru the roof or open that roof settings again
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

Eduardo Rolon
Moderator
Update:

It only happens when you increase the angle.
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

Anonymous
Not applicable
It happens because AC keeps the perpendicular thickness constant regardless of the angle. When you change the angle, the vertical thickness will (and has to) change to suit. I presume it is related to when using a composite structure fill where the perp thickness has to be constant.

As far as I know it has always been like that. At least it is consistent!

The logical solution would be to have way of 'locking' either of the thicknesses, when using a non-composite, so as to indicate which was the important one for the roof.

Perhaps start a wish for it if there isn't one already. I'd vote!
Eduardo Rolon
Moderator
The problem is that I am not selecting the perpendicular thickness of the roof but the "Y" coordinate.

Anyway that doesn't answer why it changes when you increase the angle and not when you decrease it. If it was consistent it would change for both.

The wish might sound a little absurd.

"I wish that AC does not automatically change the thickness of a roof when I increase its angle and leave it as I already specified…"


Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

Laura Yanoviak
Advocate
It's basic geometry. If the thickness of the slab is constant, and the angle changes, the "y value" must change. It's always been this way... You can always change the "y value" of a (non-composite) roof, but then the thickness of the slab will change.
MacBook Pro Apple M2 Max, 96 GB of RAM
AC26 US (5002) on Mac OS Ventura 13.5
Eduardo Rolon
Moderator
Ok, MY mistake was assuming that it was an arbitrary change. It is not. The specified thickness will stay for that particular angle, once you change it to a different angle the roof tool will recalculate the geometry.

I was thinking that changing the angle worked as if you were rotating the roof in the section/elevation, which would let the thickness stay the same and which is common in other 3D modeling programs.

Therefore Peter's suggestion about the wish for being able to lock the thickness of the roof is ok,
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

Anonymous
Not applicable
Wish made!
here.
Eduardo Rolon
Moderator
Voted and commented.

Thanks Peter.
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08

Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
another Moderator

Rick Thompson
Expert
Another good reason to use composites. I can't think of any reason not to.
Picture 1.png
Rick Thompson
Mac Sonoma AC 26
http://www.thompsonplans.com
Mac M2 studio w/ display