Change origin of wall, to help in type changes?

theoryshaw

Is there an approach, whereby you can move the origin of a wall to the middle, such that, when you change the underlying wall type of an instance--that has a different width--that it changes the width from this centerpoint?

Nigel

@theoryshaw We see this in other BIMware and it is really useful

Coen

What about this very hacky solution?

Create an IfcWall with an ExtrudeProfile with an IfcRectulangurProfileDef, so this menu will appear:

But if would be nice if the origin point could be set for vertical and horizontal layers too. But how would it then deal with multiple IfcMaterialLayers in an IfcWall?

theoryshaw

There's this of course.
https://www.dropbox.com/scl/fi/f0yjbaxjz397jv989jc56/2023-07-21_13-25-24_Blender_blender.mp4?rlkey=5a1xuyvkd85o2s5t1mnk33o9u&dl=0

Perhaps, when changing the type behind an instance, it takes the percentage of this OffsetFromReferenceLine distance to inform the new OffsetFromReferenceLine of the instance with the new type.

Existing wall thickness = 0.1
OffsetFromReferenceLine = -0 .05
Percentage = -50%

wall thickness of new type = 0.2
OffsetFromReferenceLine of wall with new type = (0.2 * -50%) = -.1

Gorgious

Isn't OffsetFromReferenceLine defined at type level rather than instance level ? If so I think you'd have to define all your wall types to be centered around the axis.

brunopostle

@Gorgious it is the opposite, a IfcMaterialLayerSetUsage can only apply to an instance (this is an IFC annoyance)

theoryshaw

I think it's an instance attribute of IfcMaterialLayerSetUsage
The IfcMaterialLayerSetUsage is always assigned to an individual occurrence object

Seems to work that way in BB, as well.

theoryshaw

Also too, i think it would be great when you change the OffsetFromReferenceLine of a wall it only moves the origin, and not the wall.
Currently it keeps the origin in the same place, and moves the wall.

theoryshaw

related: https://github.com/IfcOpenShell/IfcOpenShell/issues/3915