(Camera > Parallel Projection) and use a standard view (Top, Front, etc.) for the most accurate straight cuts. Section Cuts : Place a Section Plane, right-click it, and select " Slice Model at Section " to delete everything behind that plane. Compatibility & Installation for SketchUp 2021
Why this "ancient" split-tool remains the king of non-destructive cutting for legacy users.
: A great alternative for those who manage extensions via the SketchUcation toolset.
Unlike older versions, SketchUp 2021 is aggressive about hiding incompatible toolbars. Manually load the script: Window > Ruby Console > Type load "zorro2/zorro_loader.rb" > Press Enter.
: One of its most powerful functions is the "Slice Model at Section" feature. By right-clicking a standard SketchUp section plane, you can permanently delete all geometry behind it.