Bent section cuts

[Anonymous]

Grrr. another problem with archicad - the more you find out the more you find out how much more there is to learn...

I've been trying to get the section cuts in AC10 to bend. I'm working on a large site with buildings at different orientations and need to be able to cut a site section to display the front elevations of each of the buildings. The difference between orientations is only 10 degrees.

Whilst I have managed now to get sections to bend by fiddling around a bit, I cannot find a way to get the bend to the correct angle. Also the method in which I’ve been using the section line does not yield consistent results.

Can anyone help??

[Anonymous]

Thanks for the comments - the bent section cut was for a presentation and was requested by someone more senior than me in the company and as I'm not much more than a CAD monkey I had to find out...

cheers!

[Anonymous]

um... just thought I should post a pic so people can see why a bent section might be useful... though I do agree that it's distorting the truth somewhat

See attached jpeg. (edited in paint )

[Bricklyne Clarence]

Philip wrote:

owen wrote:
... it would be very, very useful to be able to create a curved/bent elevation.

Such as drawing flattened/unrolled elevations of a curved curtain wall....

Yes it would be a nice feature in theory BUT I cannot see it being practical for two reasons.

1. I get enough stupid questions from contractors without giving them "false" elevations to try and work with!

2. Unless the SE has a zero horizontal extent or at least a very very small one, then mathematically, it would be impossible because parts of the model would have to converge or diverge in some way.

It's fine to draw a schematic type elevation in 2D like this but it cannot work in true 3D

This isn't entirely true. In fact most other NURBS-based design programs (Rhino, Studiotools, CATIA etc) have an "unfold" function which essentially calculates and creates orthogonal unfurled single views of curved surfaces, which are necessary for CAD/CAM machining in engineering, parts manufacture, automotive and nautical design. The application of the function is obviously different, but the principle of how it works and the essential result is basically the same with the primary difference being that in those programs the algorithms that create those views are NURBS-based allowing for greater accuracy.

In Architecture, usually such functions are not necessary or available( since we don't usually design a great deal of curved and curvilinear surfaces to warrant the further development of such functions in our CAD programs) but given the relative difference in scale, of the difficulty involved and accuracy needed, there's no reason to suggest why a script function, in ArchiCAD for example, can't be written that would create, align and combine multiple section cut-lines along the desired path or curve and then to recombine all the views into one S/E window complete with lines demarcating where the single flat view folds at the various points or ends of each mini-Section cut-line to the next. It obviously sounds more complicated than it really is when you consider the fact that you can easily do it manually by creating all the necessary Sections/Elevations, aligning them as desired, creating the various views, delinking them and then copy-pasting the resulting 2D-views into one view or window. I seriously don't believe that creating such a script function is beyond the capabilities of Graphisoft developers.

The tricky part in application, obviously would be maintaining a live combined view which updates all related sections along with the model each time a change is made or the window is regenerated. We all know how (slow) AC can be with updating Sections and elevations, so now we would be talking of doing many at once. ( Here is where a desperately needed overhaul of the AC engine would come into play - and which is probably why we don't have such a function yet in ArchiCAD - because it just can't handle it at the moment.). The other caveat obviously is the fact that it would most likely be limited to a Zero-depth elevation (i.e. no background behind each mini-section), since a background in such a scenario is pointless and would needlessy make the PC choke on calulating those elements as well.

But it definitely can be done.....

[Bricklyne Clarence]

Mark wrote:
um... just thought I should post a pic so people can see why a bent section might be useful... though I do agree that it's distorting the truth somewhat

See attached jpeg. (edited in paint )

I don't see why you can't manually do that in ArchiCAD using the method I described before.

If it's just for presentation, then all you need is three separate (but end-to-end) section views as per the straight portions of your view described below, and then generate the three views, delink them (if you wish) and then copy-paste and re-combine them into one new view, marking where each separate view starts and ends with a line.

We do that all the time in our office with angular or obtusely-aligned building facades and elevations.

As has already been pointed out, there is no automated function to do all this yet in ArchiCAD; hopefully in future versions (looks like a simple Macro-script to me; but then, so do Curved profiles in plan, so what do I know).

But then again, you'll be hard pressed to find any BIM or AEC CAD program that can do bent or curved section/elevation views.