{
 "id": "28-blind-pocket-fillets",
 "name": "Blind pocket with filleted corners",
 "description": "80x60x20 block; 50x30 rectangle on top face cut 8 mm deep (blind); 4 vertical pocket corner edges filleted R5, then pocket floor edges R2.",
 "exercises": [
  "extrude_cut",
  "blind",
  "fillet",
  "concave_fillet"
 ],
 "units": {
  "length": "mm",
  "angle": "deg",
  "area": "mm2",
  "volume": "mm3"
 },
 "conventions": {
  "world": "right-handed; Z up. XY/XZ/YZ are the origin planes.",
  "sketch_frame": "sketch-local 2D coords; world = plane.origin + x*plane.x_dir + y*plane.y_dir (origin in mm). Profile 'loops' list sketch entity ids.",
  "point_refs": "'<id>.start' / '<id>.end' / '<id>.center' reuse (share) that existing sketch point; 'at' is its position when referenced.",
  "extrude_direction": "positive = along sketch plane normal unless stated",
  "selections": "selected faces/edges carry 'point': a world-space point on the face / the edge's parametric midpoint; pick the nearest face/edge to it."
 },
 "parameters": [],
 "features": [
  {
   "op": "sketch",
   "name": "Block_sketch",
   "plane": {
    "ref": "XY",
    "origin": [
     0.0,
     0.0,
     0.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     1.0,
     0.0
    ],
    "normal": [
     0.0,
     0.0,
     1.0
    ]
   },
   "entities": [
    {
     "type": "line",
     "start": {
      "at": [
       0,
       0
      ]
     },
     "end": {
      "at": [
       80,
       0
      ]
     },
     "id": "l1"
    },
    {
     "type": "line",
     "start": {
      "ref": "l1.end",
      "at": [
       80.0,
       0.0
      ]
     },
     "end": {
      "at": [
       80,
       60
      ]
     },
     "id": "l2"
    },
    {
     "type": "line",
     "start": {
      "ref": "l2.end",
      "at": [
       80.0,
       60.0
      ]
     },
     "end": {
      "at": [
       0,
       60
      ]
     },
     "id": "l3"
    },
    {
     "type": "line",
     "start": {
      "ref": "l3.end",
      "at": [
       0.0,
       60.0
      ]
     },
     "end": {
      "ref": "l1.start",
      "at": [
       0.0,
       0.0
      ]
     },
     "id": "l4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Block",
   "operation": "new",
   "profiles": [
    {
     "sketch": "Block_sketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "l1",
        "l2",
        "l3",
        "l4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 20,
    "direction": "positive"
   },
   "result_bodies": [
    "Block"
   ]
  },
  {
   "op": "sketch",
   "name": "PocketSketch",
   "plane": {
    "ref": "face: top of Block (z=20)",
    "origin": [
     0.0,
     0.0,
     20.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     1.0,
     0.0
    ],
    "normal": [
     0.0,
     0.0,
     1.0
    ],
    "face": {
     "type": "plane",
     "normal_at_point_on_face": [
      0.0,
      0.0,
      1.0
     ],
     "plane_normal_outward": [
      0.0,
      0.0,
      1.0
     ],
     "point": [
      40.0,
      30.0,
      20.0
     ]
    }
   },
   "entities": [
    {
     "type": "line",
     "start": {
      "at": [
       15.0,
       15.0
      ]
     },
     "end": {
      "at": [
       65.0,
       15.0
      ]
     },
     "id": "l1"
    },
    {
     "type": "line",
     "start": {
      "ref": "l1.end",
      "at": [
       65.0,
       15.0
      ]
     },
     "end": {
      "at": [
       65.0,
       45.0
      ]
     },
     "id": "l2"
    },
    {
     "type": "line",
     "start": {
      "ref": "l2.end",
      "at": [
       65.0,
       45.0
      ]
     },
     "end": {
      "at": [
       15.0,
       45.0
      ]
     },
     "id": "l3"
    },
    {
     "type": "line",
     "start": {
      "ref": "l3.end",
      "at": [
       15.0,
       45.0
      ]
     },
     "end": {
      "ref": "l1.start",
      "at": [
       15.0,
       15.0
      ]
     },
     "id": "l4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Pocket",
   "operation": "cut",
   "profiles": [
    {
     "sketch": "PocketSketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "l1",
        "l2",
        "l3",
        "l4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 8,
    "direction": "negative"
   },
   "result_bodies": [
    "Block"
   ]
  },
  {
   "op": "fillet",
   "name": "CornerFillet",
   "type": "constant_radius",
   "radius": 5,
   "tangent_chain": false,
   "edge_selection": "the 4 vertical pocket corner edges (z 12..20)",
   "edges": [
    {
     "type": "line",
     "start": [
      65.0,
      15.0,
      20.0
     ],
     "end": [
      65.0,
      15.0,
      12.0
     ],
     "point": [
      65.0,
      15.0,
      16.0
     ]
    },
    {
     "type": "line",
     "start": [
      15.0,
      15.0,
      20.0
     ],
     "end": [
      15.0,
      15.0,
      12.0
     ],
     "point": [
      15.0,
      15.0,
      16.0
     ]
    },
    {
     "type": "line",
     "start": [
      65.0,
      45.0,
      20.0
     ],
     "end": [
      65.0,
      45.0,
      12.0
     ],
     "point": [
      65.0,
      45.0,
      16.0
     ]
    },
    {
     "type": "line",
     "start": [
      15.0,
      45.0,
      20.0
     ],
     "end": [
      15.0,
      45.0,
      12.0
     ],
     "point": [
      15.0,
      45.0,
      16.0
     ]
    }
   ]
  },
  {
   "op": "fillet",
   "name": "FloorFillet",
   "type": "constant_radius",
   "radius": 2,
   "tangent_chain": false,
   "edge_selection": "all edges of the pocket floor (z=12) - 4 lines + 4 arcs",
   "edges": [
    {
     "type": "arc",
     "start": [
      20.0,
      45.0,
      12.0
     ],
     "end": [
      15.0,
      40.0,
      12.0
     ],
     "center": [
      20.0,
      40.0,
      12.0
     ],
     "axis": [
      0.0,
      -0.0,
      1.0
     ],
     "point": [
      16.464466094,
      43.535533906,
      12.0
     ]
    },
    {
     "type": "line",
     "start": [
      15.0,
      20.0,
      12.0
     ],
     "end": [
      15.0,
      40.0,
      12.0
     ],
     "point": [
      15.0,
      30.0,
      12.0
     ]
    },
    {
     "type": "arc",
     "start": [
      15.0,
      20.0,
      12.0
     ],
     "end": [
      20.0,
      15.0,
      12.0
     ],
     "center": [
      20.0,
      20.0,
      12.0
     ],
     "axis": [
      0.0,
      -0.0,
      1.0
     ],
     "point": [
      16.464466094,
      16.464466094,
      12.0
     ]
    },
    {
     "type": "line",
     "start": [
      60.0,
      15.0,
      12.0
     ],
     "end": [
      20.0,
      15.0,
      12.0
     ],
     "point": [
      40.0,
      15.0,
      12.0
     ]
    },
    {
     "type": "arc",
     "start": [
      60.0,
      15.0,
      12.0
     ],
     "end": [
      65.0,
      20.0,
      12.0
     ],
     "center": [
      60.0,
      20.0,
      12.0
     ],
     "axis": [
      -0.0,
      0.0,
      1.0
     ],
     "point": [
      63.535533906,
      16.464466094,
      12.0
     ]
    },
    {
     "type": "line",
     "start": [
      65.0,
      40.0,
      12.0
     ],
     "end": [
      65.0,
      20.0,
      12.0
     ],
     "point": [
      65.0,
      30.0,
      12.0
     ]
    },
    {
     "type": "arc",
     "start": [
      65.0,
      40.0,
      12.0
     ],
     "end": [
      60.0,
      45.0,
      12.0
     ],
     "center": [
      60.0,
      40.0,
      12.0
     ],
     "axis": [
      0.0,
      -0.0,
      1.0
     ],
     "point": [
      63.535533906,
      43.535533906,
      12.0
     ]
    },
    {
     "type": "line",
     "start": [
      20.0,
      45.0,
      12.0
     ],
     "end": [
      60.0,
      45.0,
      12.0
     ],
     "point": [
      40.0,
      45.0,
      12.0
     ]
    }
   ]
  }
 ]
}