IfcWallStandardCase versus IfcWall

[shorter]

Can anyone explain why a wall exports as 'IfcWallStandardCase' unless 'Export Walls/Slabs by Components' is ticked and it then exports as 'IfcWall'?

 

BuildingSmart suggests:

 

There are three entities for wall occurrences:

   

IfcWallStandardCase  used for all occurrences of walls, that have a non-changing thickness along the wall path and where the thickness parameter can be fully described by a material layer set. These walls are always represented geometrically by an 'Axis' and a 'SweptSolid' shape representation (or by a 'Clipping' geometry based on 'SweptSolid'), if a 3D geometric representation is assigned. In addition they have to have a corresponding IfcMaterialProfileSetUsage assigned.
   

IfcWallElementedCase used for occurrences of walls which are aggregated from subordinate elements, following specific decomposition rules expressed by the mandatory use of IfcRelAggregates relationship.
   

IfcWall  used for all other occurrences of wall, particularly for walls with changing thickness along the wall path (e.g. polygonal walls), or walls with a non-rectangular cross sections (e.g. L-shaped retaining walls), and walls having an extrusion axis that is unequal to the global Z axis of the project (i.e. non-vertical walls), or walls having only 'Brep', or 'SurfaceModel' geometry.

 

I do not see why a wall containing components, and that displays as IfcWallStandardCase in the OIP, should then export as IfcWall based on the above.

[zoomer]

Interesting question.

 

Not being a native speaker I get confused by the jargon already.

I often stumbled over imports not working for me as expected as

"this is an aggregated Wall" and such things ....

 

If someone could explain in simple words and step by step 🙂