AC26 missing cut fill issue in section views

[Algimantas Kuprenas]

Hello Beta Testers,

In AC26 INT 4019 and 5002 build having same issue in section views in random places.

Mesh and slab behaves strange and cut fills are missing for slab element. Made video about this issue, looks very weird behaviour while in one part of drawings it's showing cut fill but on another its missing. There are no other elements placed in that space that could cut out, when I remove mesh its looks all right.
This started to happen only in AC26 from first release. Does anyone else having similar issues with missing cut fills in section views in AC26 ? 

When I place Elevation views and use them as section then there are no issues regarding cut fills.

Video below explaining how it looks:
https://youtu.be/nM-QG8z-cEI

[Laszlo Nagy]

You should perform a Subtract SEO with the Mesh as Target and the Slab as Operator.

Slabs and Meshes do not automatically intersect based on their Building Material's Intersection Priority like many other element type combinations do (e.g., Walls and Slabs). I think this is why which one is in front of the other in Section is up to chance as you noticed.

[Algimantas Kuprenas]

Hi again,

Made another video comparing AC25 and AC26 and strange behaviour of mesh in section views. You telling that mesh is not interacting with slab elements, but it looks in section views that MESH in AC26 starts to interact with all 3D elements. Changing material priority or assigning to another layer group does not help either. Its happening not only with Mesh but also with slabs and beams in random way. Feeling like BETA tester sitting making videos and explaining bugs 😞 of course without any salary for the job.

VIDEO:
https://youtu.be/Y6KN3ofsJgc

[Laszlo Nagy]

Thanks for the video, I understand the exact nature of the issue better now.

Yes, it seems like something has changed from Ac25 to Ac26. I don't know what it was, so I cannot be of much more help here.

I still maintain that, AFAIK, these connections between Mesh and other element types are not calculated in Sections, so I would say any result you got or are getting is random, and not based on any rule, including the Bring to Front/Send to Back behavior.

Over the years, I was faced with the same issue, which I usually solved by using Lines and Fills to achieve the exact graphical representation for the Mesh in Sections. Very unBIM, but that was my workaround.

I will forward this issue to Graphisoft for investigation.

[Space_Agency]

I am seeing this issue as well in sections. A beam (used as roof rafter framing) set within a composite pitched roof does not show its cut fill. Instead archicad shows the outline of the cut beam with a transparent background, i.e. the cut fill of the roof shows through the beam. The behavior is inconsistent (some items show up randomly with cut fills). I have double checked section settings, graphic overrides, building material strength, etc. and nothing has corrected this. It would be great if there was a setting I was missing, but this sure seems to be a bug. 

 

[Algimantas Kuprenas]

This bug is fixed in AC27. Over and out, happy Beta Testing for You 😉

[Space_Agency]

Wishing that were the true in my case. The video above is of a freshly installed AC 27 using the included GRAPHISOFT template file. Have made no customizations or changes to the file, view settings, section settings, etc. Still having the same issue in both AC26 and AC 27. Hoping it is something I am just missing or that someone has some idea as to why this is occurring and how to fix it. 

[Laszlo Nagy]

The intersections of Roofs and other element types do not clear based on Intersection Priority of the Building Materials by default:

https://help.graphisoft.com/AC/27/INT/index.htm#t=_AC27_Help%2F040_ElementsVB%2F040_ElementsVB-270.h...

Select the Beam and the Roof and use the Connect > Merge Elements command of the context menu. Then the priority-based intersection will be performed on them.

[Space_Agency]

Lazlo, thanks for your reply on this as well as the link. Much appreciated. I will give this a try and hope this solves the problem for now. I’m still confused as to why some of the roof joists show with cut fills in the section and others do not. I will double check these roof joists to see if they are already merged with the roof. 

All said though, that help article shows how complicated these intersections are for what should be a really straightforward action. It seems to be another example of Graphisoft over-complicating things in the software. I’m trying to imagine a scenario where just using building material priorities for beams and roofs would be problematic when it comes to these element types intersecting, and just can’t see one.   But again, thank you for the workaround.  Hopefully all will work out. 

[Space_Agency]

Thanks again for your input. The merge does in fact work to create the cuts properly which I suppose is a good enough workaround if we have our structural members modeled within the roof element (as they would be in real life) and want their cut to show properly in section.

However, the odd bit is that prior to merging the beams, when the beams intersect a roof element I am seeing some of these beams show up with their cut fill shown somewhat properly (certain lines of the roof still show inside the cut fill of the beam), while other beams show their cut fill as transparent, i.e. the roof cut fill shows through the cut of the beam. See attached screenshot showing the roof with none of the beams merged yet.  

I might be missing something, but I still see this as an odd behavior/a bug in the software. Maybe it's just a function of an older graphics card on my end. The only other post I have seen on this is here: https://community.graphisoft.com/t5/Modeling/Complex-profile-beam-cut-fill-showing-weird-in-AC26/m-p... . 

Wondering if someone at Graphisoft might have something to add?