To cut a 3D model in a 3D workflow, use Boolean operations (e.g., subtract or split) in software like Blender or Fusion 360—select a "cutter" object (e.g., cube, plane) that intersects the target model, then apply the operation to remove or separate parts.
Boolean operations work by calculating overlapping geometry: "subtract" deletes the cutter’s area from the model, while "split" divides the model into pieces along the cutter’s path.
If the cut leaves jagged edges, use edge smoothing or simple retopology tools to clean the surface—this ensures the model is ready for downstream steps like 3D printing or rendering.