It seems like that the partial structure display still doesn't apply to the stairs. Is there any development about it in the background? what is the best workaround for that in the meantime? I can only think of duplicating the stair and play with layer combinations.
Unfortunately, no development has been done in this area since.
The only solution I can think of would involve modification of the default Tread and Riser library parts that come with Archicad. But even that would be a solution only for 3D. Here is how and why:
One of the many so-called Global Variables available in GDL contains the state of the Partial Structure Display option. It is called GLOB_STRUCTURE_DISPLAY. Here is what I did: I have created a copy of the Tread 25 Library Part, opened the copy for editing, and I inserted the following script at the very beginning of its 3D Script:
IF GLOB_STRUCTURE_DISPLAY <> 0 THEN END ENDIF
The value of GLOB_STRUCTURE_DISPLAY is 0 when the Partial Structure Display setting is set to "Entire Model". So, if it is set to any other value we do not need to generate any 3D geometry for Stair Treads. And this is what the above script does: it checks the value of GLOB_STRUCTURE_DISPLAY and if it is not zero, then it immediately ends the 3D Script without generating any 3D geometry.
So, I saved this modified Library Part and set my Stair to use this Library Part for Treads instead of the default one.
You can do the same procedure with the Riser 25 Library Part to achieve the same result.
However, I looked into the 2D Script of Tread 25, and it is so complex that I do not really want to delve into. If no Treads or Risers are displayed in 3D, they should not be displayed in 2D either, but the Structure should be, and it should be displayed with solid line type instead of dashed. This is what we would need to achieve by modifying the 2D Script, but as I said, the Script is very complex and I do not have 8-10 hours to delve into it to try to understand it and modify it.
But I think it can be done, it just requires good GDL knowledge and time to do it.
If you need to hide Treads and Riser only in 3D, this is a quick and easy solution and you can use it also to export geometry to IFC without Stair Treads/Risers. But if you need to display 2D as well without Treads and Risers, then I guess creating 2 instances on different Layers is the way to go for now.
I have attached the two modified Library Parts for anyone interested. Only the 3D Script of each was modified by adding the above mentioned lines of code.
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