Fix(rebar): use shell geometry if rebars are not exported as SweptDiskSolids

[MiguelG97]

Fix #146

Description

This PR fixes how reinforcing rebars are loaded into fragments when they aren’t exported as SweptDiskSolid. if a rebar doesn’t have a valid directrix axis, it falls back to loadShellGeometry so it still shows up in the scene.

Additional context

Before, the code assumed all IFCREINFORCINGBAR geometries had a SweptDiskSolid with a directrix. But some IFC exports (like from Tekla) might be configured to export rebars as IfcFacetedBrep, which doesn’t have that data. That made loadCircleExtrusionGeometry fail and the rebars wouldn’t load.

rebars.not.rendering.mov

Now, this change checks if the sweep directrix exists and uses the shell loader if it doesn’t, so all rebars get parsed and rendered correctly.

rebars.rendering.mov

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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