Dissappearing objects in sections

[Anonymous]

Does anyone know why some objects seem to dissappear in section view? I'm using structural beams which appear OK in 3D and 3D marquee but when I cut a section through the beam - it dissappears. Any ideas?

[Richard Morrison]

One basic thing to check would be your section properties for the beam. If you've got it set to a white pen and also have a white display background, you won't see much. Also check that the section vertical range will include the height of the beam. Finally, check your "Elements to Show in 3D" dialog.

[Anonymous]

Richard,

thanks for your reply. I have checked the things you mention. One thing I didn't say was that the objects are visible if the section doesn't actually cut through them but looks at them. The same thing happens in the 3d window sometimes.

Interestingly, I have replaced the beam object with another from a different library which doesn't have this problem. All of this makes me think that it must be due to the actual object code itself. Not being proficient in GDL - I can't take it much further at this point.

[Djordje]

Ian wrote:
Does anyone know why some objects seem to dissappear in section view? I'm using structural beams which appear OK in 3D and 3D marquee but when I cut a section through the beam - it dissappears. Any ideas?

If it is not an irregular shape, why not use the beam tool?

Or is it a part of the wooden roof structure?

Also - which version of ArchiCAD and which library?

Use the signature ... one of the reasons it is there.

[Anonymous]

Djorde,

I wanted to use a specific structural section rather than just a rectangular object. The objects came from the ArchiCad 9 library "Steel Structure 9". The objects which were still visible when cut by the section come from Australian Essential Library - BHP Sections".

I have found a work-around however I'm interested to know why this happens in some cases and not in others.

[Ted Taylor]

Ian

Another thing to check to see if duplicate items are occupying the same spot. Sections cut through the objects will behave as you describe but will be visible in elevation if not cut through.

What was your work around?

[Djordje]

Ian wrote:
I wanted to use a specific structural section rather than just a rectangular object. The objects came from the ArchiCad 9 library "Steel Structure 9". The objects which were still visible when cut by the section come from Australian Essential Library - BHP Sections".

Oh, that is right then!

Ian wrote:
I have found a work-around however I'm interested to know why this happens in some cases and not in others.

As Ted noted, check the duplicates; if you do have duplicates, they will not show in S/E. Also, check whether the layer is not off in the layer combo - it is easy to put the objects on a wrong layer.

[Anonymous]

Thanks for the comments.

There are no duplicates and the objects are on the correct layer. The work-around I described is simply deleting the objects which don't appear and replacing them with the other ones which do.

It is similar to the problem with stairs where they will sometimes dissappear in marquee 3d view whilst being visible in full 3d view. The dissappearing beam objects will also dissappear in 3d if cut by a marquee but will be visible if the marquee does not cut them.

I have absolutely no idea why this happens but I would be interested to find out. It is an annoying bug.

[Laszlo Nagy]

A small ArchiCAD PLA zipped and posted containing the buggy part could help us find out the source of the problem.

[Aussie John]

I have noticed that too, and it is not duplicates. Try replacing the errant object with a new version. That sometimes fixes things.