{
 "id": "15-combine-intersect",
 "name": "Boolean intersect",
 "description": "Cube 40 centred at origin intersected with sphere r=25 at origin.",
 "exercises": [
  "extrude",
  "symmetric",
  "revolve",
  "combine_intersect"
 ],
 "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": "CubeSketch",
   "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": [
       -20,
       -20
      ]
     },
     "end": {
      "at": [
       20,
       -20
      ]
     },
     "id": "l1"
    },
    {
     "type": "line",
     "start": {
      "ref": "l1.end",
      "at": [
       20.0,
       -20.0
      ]
     },
     "end": {
      "at": [
       20,
       20
      ]
     },
     "id": "l2"
    },
    {
     "type": "line",
     "start": {
      "ref": "l2.end",
      "at": [
       20.0,
       20.0
      ]
     },
     "end": {
      "at": [
       -20,
       20
      ]
     },
     "id": "l3"
    },
    {
     "type": "line",
     "start": {
      "ref": "l3.end",
      "at": [
       -20.0,
       20.0
      ]
     },
     "end": {
      "ref": "l1.start",
      "at": [
       -20.0,
       -20.0
      ]
     },
     "id": "l4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "CubeA",
   "operation": "new",
   "profiles": [
    {
     "sketch": "CubeSketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "l1",
        "l2",
        "l3",
        "l4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "symmetric",
    "distance": 20,
    "is_full_length": false,
    "meaning": "distance on each side"
   },
   "result_bodies": [
    "A"
   ]
  },
  {
   "op": "sketch",
   "name": "SphereB_sketch",
   "plane": {
    "ref": "XZ",
    "origin": [
     0.0,
     0.0,
     0.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     0.0,
     -1.0
    ],
    "normal": [
     0.0,
     1.0,
     0.0
    ]
   },
   "entities": [
    {
     "type": "arc_three_point",
     "start": {
      "at": [
       0.0,
       25.0
      ]
     },
     "mid": [
      25.0,
      0.0
     ],
     "end": {
      "at": [
       0.0,
       -25.0
      ]
     },
     "id": "a1"
    },
    {
     "type": "line",
     "start": {
      "ref": "a1.end",
      "at": [
       0.0,
       -25.0
      ]
     },
     "end": {
      "ref": "a1.start",
      "at": [
       0.0,
       25.0
      ]
     },
     "id": "l1"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "revolve",
   "name": "SphereB",
   "operation": "new",
   "profile": {
    "sketch": "SphereB_sketch",
    "loops": [
     {
      "outer": true,
      "curves": [
       "a1",
       "l1"
      ]
     }
    ]
   },
   "axis": {
    "ref": "world Z axis",
    "origin": [
     0,
     0,
     0
    ],
    "dir": [
     0,
     0,
     1
    ]
   },
   "angle": 360,
   "result_bodies": [
    "B"
   ]
  },
  {
   "op": "combine",
   "name": "Combine1",
   "operation": "intersect",
   "target_body": "A",
   "tool_bodies": [
    "B"
   ],
   "keep_tools": false
  }
 ]
}