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Tessellation + Opening

Hi all,
I have a question regarding geometry in IFC4:
Is it allowed to have a wall (for instance) with tessellated geometry AND a void element, connected to this Wall, with an opening represented by exact geometry (such as extruded area solid) ?
I had a look to the documentation but i didn’t find the answer.
Thank you.

Up,
Does someone has any idea ?

Hi,

In geometry/topology related areas I have few knowledge and experience, especially on IFC

But it seems that I can guess what are you talking about:

Have you faced this: You have a wall with a lot of layers and want have a void/boolean (with a customized shape) that effects on “ALL” layers?

I don’t see why not. I don’t think the void relationships cares about the geometric representation.

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Hi,

No, i’m talking about a more simpler model. Just a wall, with an opening. The geometry of the wall is defined with IfcTessellatedFaceSet. The geometry of the opening is defined as exact geometry, such as extruded area solid.
So we are processing a boolean operation between tessellated and exact geometry.
I’m wondering if it is correct.

Ok,
I’m asking this because the boolean operation will be done between a tessellated object and an exact one.

@TLiebich might be the best person to answer this, but I believe it depends on the MVD requirements.
@kevin.nahaboo For the RV1.2, see this:
https://standards.buildingsmart.org/MVD/RELEASE/IFC4/ADD2_TC1/RV1_2/HTML/
and look for this:

For a DTV, I assume it would require CSGs as Tesselation of Walls are not with scope.
This should answer your question?

8 posts were split to a new topic: Conversion between geometry type representations

I also don’t see why this should be not allowed, but obviously it does not conform to any of the two main MVDs and software certified against one of those may not be able to read it.

I would be curious to know in what scenario this case appears. Is it alteration of an existing building, where you plan an opening in a wall generated from a point cloud?

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