Dwight wrote: Link has already identified the "free line cut" method you ask for - as close as it can be in ArchiCAD:
ahem ... I still prefer spline magicwanded into marquee, and then, if needed, SEOs.
Volumetric = something that has volume.
Dwight wrote: You can also define your visualization area with a complex marquee, selecting only the storey you want to visualize.... and preserving the marquee path by using an outline on a special layer....
... not to mention the 3D view that should (have to try it properly!) preserve the marquee and the storey visibility
Now nobody mentioned GDL? 😉 Parametric cutplanes? Remember the building growing up? MUCH before SEOs, in Matthew's junior days 😉