{
  "object_category": "fitness equipment (adjustable weight bench)",
  "granularity_level": "medium",
  "segmentation_principle": "Separate the primary adjustable seat and frame from the rigid base, as these are the main kinematic bodies with independent movement, while smaller adjustment parts are integrated into the frame.",
  "articulated_components": [
    "adjustable seat, backrest (if present), adjustment levers, foot rollers"
  ],
  "fixed_components": [
    "base frame, main support structure"
  ],
  "sam2_failure_modes": [
    "SAM2 may over-segment the small adjustment levers or merge the foot rollers with the frame, or under-segment the seat by splitting it into the cushion and metal parts."
  ]
}