nat88:
A crude solution is to make a copy of the library part and add one line to the 3D Script:
1.
Open Object... Corrugated Sheet Vert 15
2. Save As... this object to a loaded library folder or the Embedded Library with a different name
3. Go to the 3D Script of the new object and add
RotY -90 near the top (see illustration)
4. Save the new altered object
This change will rotate the panel in 3D. It does not correct the 2D Symbol or the parameters, but the hotspots in the 3D Window work, so if this is just for 3D should be ok.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David