topic Re: Intersection of different objects vs display order in Modeling

Intersection of different objects vs display order

Anonymous — Tue, 23 May 2023 14:14:51 GMT

Hi all,

I'm having trouble understanding the logic of Display Order in 2D plan view versus the intersection abilities of the Layer Intersection Group.

See attached example.

The two walls are on different layers, with their Layer Intersection numbers at 1, so they intersect. The wall going left right has a higher Building Material priority "strength" than the wall going up down (insulation), thus, in 3D, the concrete blockwall correctly goes through the Insulation wall.

HOWEVER, in 2D, by using the Display Order, I am able to override this, which seems counter-intuitive and dangerous.

Isn't this going against the purpose of this software? I.e. for 3D modelling to accurately represent itself automatically in 2D drawings...?

If anyone could shed some light about this phenomenon that would be appreciated.

Thanks,
Ben

Re: Intersection of different objects vs display order

Barry Kelly — Thu, 22 Jun 2017 06:38:03 GMT

benjamin_chan wrote:
HOWEVER, in 2D, by using the Display Order, I am able to override this, which seems counter-intuitive and dangerous.

Isn't this going against the purpose of this software? I.e. for 3D modelling to accurately represent itself automatically in 2D drawings...?

If anyone could shed some light about this phenomenon that would be appreciated.

It is automatic.
You are manually adjusting the 2D display.
You would only do this if you had a reason to do so.

Barry.

Re: Intersection of different objects vs display order

Anonymous — Thu, 22 Jun 2017 06:45:07 GMT

It is automatic.
You are manually adjusting the 2D display.
You would only do this if you had a reason to do so.

Barry.

Yes, I understand that. I guess my question is why would ARCHICAD give you the ability to manually adjust something that would inaccurately reflect what is happening in 3D.

Re: Intersection of different objects vs display order

Barry Kelly — Thu, 22 Jun 2017 07:10:40 GMT

The 2D plan view is just a symbolic representation of the 3D top view.
I guess Archicad is letting you choose how you want that representation to behave.

Having said that I was just experimenting and I can not bring the display of a weaker BM wall in front of a stronger one.
Unless I turn the 'Clean Wall & Beam Intersections' option off in the on screen display options.
Which is not something you would not want to do as your corner wall intersections will not trim properly.

Barry.

Re: Intersection of different objects vs display order

Anonymous — Thu, 22 Jun 2017 07:18:32 GMT

Barry wrote:
The 2D plan view is just a symbolic representation of the 3D top view.
I guess Archicad is letting you choose how you want that representation to behave.

Having said that I was just experimenting and I can not bring the display of a weaker BM wall in front of a stronger one.
Unless I turn the 'Clean Wall & Beam Intersections' option off in the on screen display options.
Which is not something you would not want to do as your corner wall intersections will not trim properly.

Barry.

That seems reasonable, thanks Barry.

Re: Intersection of different objects vs display order

Anonymous — Tue, 04 Jul 2017 01:05:27 GMT

Hi,

I have encountered another scenario which I find very puzzling. I have a conventional 3D model of a house where walls sit on top of the slab. However, in 2D, using the display order, I can very easily put the slab on top of the walls. But obviously the slab hasn't moved.

Why would this feature be available? I can't see a scenario in which in 2D you want to "cheat' the display order of how you have modelled it in 3D.

Re: Intersection of different objects vs display order

Barry Kelly — Tue, 04 Jul 2017 01:46:21 GMT

You probably wouldn't want to do that with a floor slab.
But maybe you have a bench top or shelf - add a cover fill and bring to front and it will hide what ever is below - if you want to do that.
Or you could add a 50% cover fill to your floor slab and bring that to the front to help show the extent of the slab.

Most of the time the default order is perfectly fine, but there will be occasions when you want to change it.

Fills for example will always default to the background - but there are times when you will want to pull these forward.

Basically if it looks good, leave it. But you have the option to change it if you want.

Barry.

Re: Intersection of different objects vs display order

Anonymous — Tue, 04 Jul 2017 01:47:50 GMT

Hmmm OK - thanks Barry. Will take time to get my head around it.

Re: Intersection of different objects vs display order

Bruce — Tue, 04 Jul 2017 08:02:32 GMT

benjamin_chan, if I had to guess, I would say you are coming over from Revit.

Revit will do a live model display, which prevents things like you mention, but also slows down your model.

ARCHICAD uses interpretive display, which makes for much faster refresh, but means the display order is up to the user.

Re: Intersection of different objects vs display order

Anonymous — Tue, 04 Jul 2017 08:20:44 GMT

Hi Bruce,
Interestingly no - I come from the land of Vectorworks & SketchUp, and the occasional AutoCAD.

Thanks for the explanation.
Ben

Re: Intersection of different objects vs display order

Anonymous — Tue, 04 Jul 2017 12:30:52 GMT

Barry wrote:
You probably wouldn't want to do that with a floor slab.
But maybe you have a bench top or shelf - add a cover fill and bring to front and it will hide what ever is below - if you want to do that.
Or you could add a 50% cover fill to your floor slab and bring that to the front to help show the extent of the slab.

Most of the time the default order is perfectly fine, but there will be occasions when you want to change it.

Fills for example will always default to the background - but there are times when you will want to pull these forward.

Basically if it looks good, leave it. But you have the option to change it if you want.

Barry.

Sorry to harp on about this but it's on my mind.....

The example you mentioned is a 2D element (fill) and a 3D object (bench top etc.). Wouldn't it make more sense if ARCHICAD forbids display order manipulation for 3D + 3D objects (like my example of the wall and slab conundrum) - but only permit display order manipulation to 2D + 2D objects or 2D + 3D objects (like your example of 2D fills with 3D objects)

Unless there's something I'm missing that makes sense for a user to be able to manipulate the display order of two overlapping 3D objects in a 2D view....

Re: Intersection of different objects vs display order

Erwin Edel — Tue, 04 Jul 2017 12:46:58 GMT

Floor plan is pretty much the only view that is not a true 3D projection. I find myself using drawing order (bring to front, send to back etc) the most in these views and yes this works with 3D elements. This also means you, for example, can bring to front a wall that would sit below a pitched roof, override the walls true 3D projection to a dashed line and create a 2D information that is understandable.

Some things are weird, but some other things can work nicely.

Display order works in elevations and sections too, even with 3D elements, which means you could partially hide added 2D elements with the 3D elements.

Re: Intersection of different objects vs display order

runxel — Wed, 05 Jul 2017 12:17:05 GMT

benjamin_chan wrote:
Wouldn't it make more sense if ARCHICAD forbids display order manipulation ?

Unless there's something I'm missing that makes sense for a user to be able to manipulate the display order of two overlapping 3D objects in a 2D view....

No, it wouldn't! Thankfully you can do this kind of trickery, sometimes it is even necessary.
(Elevations e.g.)

Sad thing is that it is often not predictable. (Like you hit the "down" button, nothing changes. And then suddenly it springs directly to the background.)

Re: Intersection of different objects vs display order

Anonymous — Thu, 06 Jul 2017 09:50:21 GMT

runxel wrote:
No, it wouldn't! Thankfully you can do this kind of trickery, sometimes it is even necessary.
(Elevations e.g.)

Sad thing is that it is often not predictable. (Like you hit the "down" button, nothing changes. And then suddenly it springs directly to the background.)

Not sure in what situation in a 2D elevation would you want to change the display order of 3D objects? (I am talking about the 3D object display order manipulation only). To your second point - yes - it is quite unpredictable....

Erwin wrote:
Floor plan is pretty much the only view that is not a true 3D projection. I find myself using drawing order (bring to front, send to back etc) the most in these views and yes this works with 3D elements. This also means you, for example, can bring to front a wall that would sit below a pitched roof, override the walls true 3D projection to a dashed line and create a 2D information that is understandable.

Hi Erwin, is there a screenshot I could see to see what you are doing. In my roof plans, I am able to do what you seem to be saying without having to resort to display order.

Roof plan view settings shows 1 story down.
Floor below (ground floor) has all its walls as "All Relevant Stories"
Graphic Override has a rule that says any 3D objects that has its home story on Ground Floor shows as dashed line.

Re: Intersection of different objects vs display order

Barry Kelly — Fri, 07 Jul 2017 01:02:09 GMT

benjamin_chan wrote:
In my roof plans, I am able to do what you seem to be saying without having to resort to display order.

Roof plan view settings shows 1 story down.
Floor below (ground floor) has all its walls as "All Relevant Stories"
Graphic Override has a rule that says any 3D objects that has its home story on Ground Floor shows as dashed line.

But remember that Graphic Overrides is new in version 20 - was not available in earlier versions.

Barry.

Re: Intersection of different objects vs display order

Anonymous — Fri, 07 Jul 2017 02:11:15 GMT

Ah of course...........got it
Thanks

Re: Intersection of different objects vs display order

Erwin Edel — Mon, 10 Jul 2017 11:21:01 GMT

Regardless of graphic overrides, I have coverfill on my roofs with a solid white background, so I don't think you will see those walls, unless you use the display order to bring them to front one or two steps.