The best way to cut a building’s 3D model depends on your goal: use **section planes** for non-destructive internal views (e.g., floor plans, structural details) or **boolean operations** for permanent geometry edits (e.g., openings, custom cuts)—common tools in SketchUp, Blender, or Revit.
Section planes let you visualize interiors without changing the original model, ideal for design reviews or client presentations. Boolean tools (subtract/intersect) permanently modify geometry, perfect for finalizing openings like windows or doors.
For beginners, start with SketchUp’s intuitive section planes. For permanent edits, use Blender’s free boolean modifiers (great for 3D modeling) or Revit’s split tools (optimized for BIM workflows).