Differentiating IfcGrid


does anyone know if it is possible to have two different types of IfcGrid in IFC? Currently, all software export all grid elements under one entity, namely IfcGrid. I did not find a possibility to differentiate between two different types of grids. These two grid types in my project are all linear, but have different purposes. One is the used to define construction elements and the other to define room locations (based on the intersections of the linear grid).
It would be useful to have the possibility to turn On/Off these elements separately. When all grid elements are visible, it is very difficult to find the correct grid lines or intersections. It is a drawing full of lines :worried:

Which possibilities are there to apply this differentiation?

I don’t believe there are any restrictions on include more than one IfcGrid… in fact, I think we tested having multiple grids in one file for IFC2x3 and IFC4 certification.

They just need to be named uniquely, as well as being properly structured with multiple IfcGridAxis within the respective IfcGrid. Maybe it was a user error in creating them?

The only hint that I found in IFC4 specification for a differentiation of Axis are the Attributes Name and Description. I can confirm that the BIM authoring software exports these two grids with correct attributes.

There are different results while importing it in a viewer. At this step I get different results. Some don’t show at all the grid, and some are capable of presenting it in 3D and also in the IFC Structure. But that’s all. It is not possible to turn On/Off these two types of grid. This is the case of most of the viewer software.
Though in BlenderBIM I could confirm that it is possible to turn On/Off the visibility of the grid, meaning the IFC Structure is correct. Therefore, I can conclude that Software vendors did not implement this step correctly.
thank you for the explanation…

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