{
 "id": "16-sweep",
 "name": "Sweep along path",
 "description": "d=6 circle on XY at origin swept along a path on XZ: line up 30, tangent R20 arc, line 30 along +X.",
 "exercises": [
  "sketch_xz",
  "sweep",
  "path_chain"
 ],
 "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": "Path",
   "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": "line",
     "start": {
      "at": [
       0.0,
       0.0
      ]
     },
     "end": {
      "at": [
       0.0,
       -30.0
      ]
     },
     "id": "l1"
    },
    {
     "type": "arc_three_point",
     "start": {
      "ref": "l1.end",
      "at": [
       0.0,
       -30.0
      ]
     },
     "mid": [
      5.857864376,
      -44.142135624
     ],
     "end": {
      "at": [
       20.0,
       -50.0
      ]
     },
     "id": "a1"
    },
    {
     "type": "line",
     "start": {
      "ref": "a1.end",
      "at": [
       20.0,
       -50.0
      ]
     },
     "end": {
      "at": [
       50.0,
       -50.0
      ]
     },
     "id": "l2"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "sketch",
   "name": "ProfileSketch",
   "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": "circle",
     "center": {
      "at": [
       0,
       0
      ]
     },
     "radius": 3,
     "id": "c1"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "sweep",
   "name": "Sweep1",
   "operation": "new",
   "profile": {
    "sketch": "ProfileSketch",
    "loops": [
     {
      "outer": true,
      "curves": [
       "c1"
      ]
     }
    ]
   },
   "path": {
    "sketch": "Path",
    "curves": [
     "l1",
     "a1",
     "l2"
    ],
    "chained": true
   },
   "orientation": "perpendicular",
   "result_bodies": [
    "Tube"
   ]
  }
 ]
}