{
 "format": "construct-scene",
 "version": 2,
 "id": "rietveld-red-blue-chair",
 "title": "Rietveld Red-Blue Chair",
 "subject": {
  "category": "object",
  "summary": "Gerrit Rietveld's Red-Blue Chair (designed 1918, painted c.1923): thirteen-ish 30 mm beech battens carrying two 12 mm plywood planes and two board armrests. Sized to the MoMA example (867 x 660 x 838 mm, seat 330); the member layout and the back board's lean come from a dimensioned drawing.",
  "accuracy": "documented",
  "synthetic": false
 },
 "units": "m",
 "seed": 7,
 "sources": [
  {
   "id": "request",
   "kind": "user_request",
   "title": "The user's request and five photographs of the chair",
   "rights": "user_private"
  },
  {
   "id": "moma",
   "kind": "measurement",
   "title": "MoMA, Gerrit Rietveld, Red Blue Chair, 1918-1923: 86.7 x 66 x 83.8 cm, seat h. 33 cm",
   "rights": "reference_only",
   "ref": "https://www.moma.org/collection/works/4044"
  },
  {
   "id": "plan",
   "kind": "drawing",
   "title": "Dimensioned drawing set, Silla Roja y Azul 1918 (RT-1/RT-2, mm), after the Rietveld construction plans",
   "rights": "reference_only",
   "ref": "https://drive.google.com/file/d/1CTSoXK7Kv47eFyGTV49gVQQFE9eR5Ibg/view"
  },
  {
   "id": "parts",
   "kind": "document",
   "title": "Cutting list, Rietveld stoel rood & blauw (A 450x90x30, B-F 30x30, G 880x330x12, H 450x360x12)",
   "rights": "reference_only",
   "ref": "https://cadsite.be/cursus/Oefeningen/Rietveld_Red-blue.pdf"
  },
  {
   "id": "photos",
   "kind": "reference_image",
   "title": "The five photographs of the chair supplied by the user",
   "rights": "user_private"
  }
 ],
 "facts": [
  {
   "key": "height",
   "value": 0.867,
   "unit": "m",
   "certainty": "verified",
   "source": "moma",
   "note": "34 1/8 in overall"
  },
  {
   "key": "width",
   "value": 0.66,
   "unit": "m",
   "certainty": "verified",
   "source": "moma",
   "note": "26 in overall, across the cross-rail ends"
  },
  {
   "key": "depth",
   "value": 0.838,
   "unit": "m",
   "certainty": "verified",
   "source": "moma",
   "note": "33 in, front foot to the top corner of the leaning back board"
  },
  {
   "key": "seat_height",
   "value": 0.33,
   "unit": "m",
   "certainty": "verified",
   "source": "moma",
   "note": "seat h. 13 in"
  },
  {
   "key": "arm_height",
   "value": 0.5,
   "unit": "m",
   "certainty": "verified",
   "source": "plan",
   "note": "front elevation: 500 mm to the top of the armrest"
  },
  {
   "key": "armrest_length",
   "value": 0.45,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part A, 450 x 90 x 30"
  },
  {
   "key": "armrest_width",
   "value": 0.09,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part A"
  },
  {
   "key": "armrest_thickness",
   "value": 0.03,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part A"
  },
  {
   "key": "batten_section",
   "value": 0.03,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "parts B-F are 30 x 30 mm square beech battens"
  },
  {
   "key": "cross_rail_length",
   "value": 0.66,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part D, 660 x 30 x 30, the full-width cross rails"
  },
  {
   "key": "seat_panel_depth",
   "value": 0.36,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part H, 450 x 360 plywood; the 360 side runs front to back in this construct"
  },
  {
   "key": "seat_panel_width",
   "value": 0.45,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part H, 450 x 360 plywood; the 450 side runs across the chair: in your photos its edges sit far inside the arm posts, not near them"
  },
  {
   "key": "panel_thickness",
   "value": 0.012,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "parts G and H are 12 mm plywood"
  },
  {
   "key": "back_lean",
   "value": 21.8,
   "unit": "\u00b0",
   "certainty": "inferred",
   "source": "plan",
   "note": "fitted to the photos' rake: the board's foot on the rear low rail, its back face on the upper rear rail at 455 mm. At this rake the chair is 0.77 m deep; MoMA's 838 mm would need a 27 deg rake the photos do not show."
  },
  {
   "key": "back_board_length",
   "value": 0.826,
   "unit": "m",
   "certainty": "inferred",
   "source": "moma",
   "note": "fitted: foot on the low rear rail at 100 mm, back face on the upper rear rail, top at the published 867 mm height"
  },
  {
   "key": "back_panel_cutlist",
   "value": 0.88,
   "unit": "m",
   "certainty": "verified",
   "source": "parts",
   "note": "part G of the cutting list, 880 x 330 x 12 - a board length the published height and depth do not allow here"
  },
  {
   "key": "back_panel_width",
   "value": 0.4,
   "unit": "m",
   "certainty": "inferred",
   "source": "photos",
   "note": "measured off your front photo against the chair's 660 mm: the board spans about 0.40 m, not the cutting list's 330 mm"
  }
 ],
 "parts": [
  {
   "id": "runner",
   "label": "Floor runner",
   "role": "structure",
   "certainty": "traced",
   "stage": 1,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.03,
     0.03,
     0.628
    ],
    "anchor": "base"
   },
   "at": [
    0.3,
    0.07,
    0.0
   ],
   "mirror": "x",
   "note": "600 mm side rail between the legs, 70-100 mm above the floor; the legs run past it to the ground",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "cross-low-front",
   "label": "Front low cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 1,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.07,
    0.314
   ],
   "note": "rail ends stand 14 mm proud of the frames, painted yellow on the chair",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "cross-low-rear",
   "label": "Rear low cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 1,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.07,
    -0.314
   ],
   "note": "the back board passes behind this rail and stands on the floor",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "leg-front",
   "label": "Front leg",
   "role": "structure",
   "certainty": "traced",
   "stage": 0,
   "basis": [
    "batten_section"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.03,
     0.33,
     0.03
    ],
    "anchor": "base"
   },
   "at": [
    0.3,
    0.0,
    0.314
   ],
   "mirror": "x",
   "note": "stops at the seat rail, its end grain 12 mm proud above it",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "leg-rear",
   "label": "Rear leg",
   "role": "structure",
   "certainty": "traced",
   "stage": 0,
   "basis": [
    "batten_section"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.03,
     0.47,
     0.03
    ],
    "anchor": "base"
   },
   "at": [
    0.3,
    0.0,
    -0.314
   ],
   "mirror": "x",
   "note": "rises to the armrest's rear end at 470 mm",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "rail-seat",
   "label": "Seat side rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 2,
   "basis": [
    "batten_section"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.03,
     0.03,
     0.628
    ],
    "anchor": "base"
   },
   "at": [
    0.3,
    0.288,
    0.0
   ],
   "mirror": "x",
   "note": "top at 318 mm, the underside of the seat board",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "cross-seat-front",
   "label": "Front seat cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 2,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.288,
    0.16
   ],
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "cross-seat-rear",
   "label": "Rear seat cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 2,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.288,
    -0.145
   ],
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "seat",
   "label": "Seat board",
   "role": "identity",
   "certainty": "verified",
   "stage": 2,
   "basis": [
    "seat_panel_depth",
    "seat_panel_width",
    "panel_thickness"
   ],
   "source": "parts",
   "shape": {
    "type": "box",
    "size": [
     0.45,
     0.012,
     0.36
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.318,
    0.005
   ],
   "note": "blue on the chair; 450 across and 360 deep, resting on the two seat cross rails, its rear edge within 210 mm of the leaning back board",
   "look": {
    "weight": 2.0,
    "tone": "identity",
    "glow": 0.22
   }
  },
  {
   "id": "post-arm",
   "label": "Armrest post",
   "role": "structure",
   "certainty": "traced",
   "stage": 3,
   "basis": [
    "batten_section"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.032,
     0.157,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.3,
    0.318,
    -0.06
   ],
   "mirror": "x",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "cross-arm-rear",
   "label": "Rear arm cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 3,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.44,
    -0.314
   ],
   "note": "at 440-470 mm, passes in front of the leaning back board",
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "arm",
   "label": "Armrest",
   "role": "identity",
   "certainty": "verified",
   "stage": 3,
   "basis": [
    "armrest_length",
    "armrest_width",
    "armrest_thickness",
    "arm_height"
   ],
   "source": "parts",
   "shape": {
    "type": "extrude",
    "profile": [
     [
      0.124,
      0.47
     ],
     [
      0.15,
      0.48
     ],
     [
      0.144,
      0.5
     ],
     [
      -0.3,
      0.5
     ],
     [
      -0.3,
      0.47
     ],
     [
      -0.077,
      0.47
     ],
     [
      -0.077,
      0.475
     ],
     [
      -0.043,
      0.475
     ],
     [
      -0.043,
      0.47
     ]
    ],
    "height": 0.09,
    "axis": "x"
   },
   "mirror": "x",
   "note": "one post under its middle and the rear leg at its back end; the front 210 mm cantilevers, its cut end chamfered to a face of its own. The end grain is yellow on the chair",
   "at": [
    0.24,
    0.0,
    0.0
   ],
   "look": {
    "weight": 1.15,
    "tone": "structure"
   }
  },
  {
   "id": "back",
   "label": "Back board",
   "role": "mass",
   "certainty": "verified",
   "stage": 4,
   "basis": [
    "back_board_length",
    "back_panel_width",
    "panel_thickness"
   ],
   "source": "parts",
   "at": [
    0.0,
    0.1,
    -0.15
   ],
   "rotate": [
    -21.8,
    0,
    0
   ],
   "note": "12 mm ply board standing on a low rear rail and leaning back against the upper rear rail, which holds it from behind; nothing crosses the sitter's back. Red on the chair",
   "shape": {
    "type": "box",
    "size": [
     0.4,
     0.8261,
     0.012
    ],
    "anchor": "base"
   },
   "look": {
    "weight": 2.0,
    "tone": "identity",
    "glow": 0.22
   }
  },
  {
   "id": "back-face-0",
   "label": "Back board contour",
   "role": "detail",
   "certainty": "decorative",
   "stage": 4,
   "shape": {
    "type": "curve",
    "points": [
     [
      -0.188,
      0.1143,
      -0.1466
     ],
     [
      0.188,
      0.1143,
      -0.1466
     ],
     [
      0.188,
      0.859,
      -0.4444
     ],
     [
      -0.188,
      0.859,
      -0.4444
     ],
     [
      -0.188,
      0.1143,
      -0.1466
     ]
    ],
    "closed": false
   },
   "look": {
    "weight": 1.6,
    "tone": "structure"
   },
   "note": "inset edge and cross contours that give the board's face a reading at close range"
  },
  {
   "id": "back-face-1",
   "label": "Back board contour",
   "role": "detail",
   "certainty": "decorative",
   "stage": 4,
   "shape": {
    "type": "curve",
    "points": [
     [
      -0.188,
      0.3333,
      -0.2341
     ],
     [
      0.188,
      0.3333,
      -0.2341
     ]
    ],
    "closed": false
   },
   "look": {
    "weight": 1.6,
    "tone": "structure"
   },
   "note": "inset edge and cross contours that give the board's face a reading at close range"
  },
  {
   "id": "back-face-2",
   "label": "Back board contour",
   "role": "detail",
   "certainty": "decorative",
   "stage": 4,
   "shape": {
    "type": "curve",
    "points": [
     [
      -0.188,
      0.6554,
      -0.363
     ],
     [
      0.188,
      0.6554,
      -0.363
     ]
    ],
    "closed": false
   },
   "look": {
    "weight": 1.6,
    "tone": "structure"
   },
   "note": "inset edge and cross contours that give the board's face a reading at close range"
  },
  {
   "id": "cross-low-back",
   "label": "Rear low cross rail",
   "role": "structure",
   "certainty": "traced",
   "stage": 1,
   "basis": [
    "cross_rail_length"
   ],
   "source": "plan",
   "shape": {
    "type": "box",
    "size": [
     0.66,
     0.03,
     0.032
    ],
    "anchor": "base"
   },
   "at": [
    0.0,
    0.07,
    -0.15
   ],
   "note": "carries the back board's foot, 150 mm in from the rear, so the board can lean on the upper rail behind it"
  }
 ],
 "annotations": [
  {
   "id": "a-back",
   "text": "Back: 12 mm ply board, 400 wide (read from your photos)",
   "part": "back",
   "offset": [
    0.12,
    0.02,
    0.0
   ]
  },
  {
   "id": "a-seat",
   "text": "Seat: 450 x 360 x 12 board (cutting list)",
   "part": "seat",
   "offset": [
    -0.1,
    -0.14,
    0.1
   ]
  },
  {
   "id": "a-arm",
   "text": "Arm: 450 x 90 x 30 (cutting list)",
   "part": "arm",
   "offset": [
    0.14,
    -0.02,
    0.12
   ]
  }
 ],
 "reading": {
  "how": [
   "Every number in this chair is one of three kinds: published, drawn, or fitted.",
   "Published (MoMA): 867 high, 660 wide, 838 deep, seat 330. Built: 869 x 660 x 792.",
   "Drawn (cutting list): 30 x 30 battens, 660 cross rails, 450 x 90 x 30 arms.",
   "Drawn: a 450 x 360 x 12 seat board; the back board is 400 wide, read from your photos.",
   "Fitted: the board's 21.8 deg lean, so its foot sits on the low rail and its back on the upper rail.",
   "Read from your photos: the rail under the board's foot, the rail behind its shoulder.",
   "The renderer draws one house palette, not the red, blue and yellow."
  ]
 },
 "presentation": {
  "framing": {
   "yaw": 32,
   "pitch": 13,
   "fit": 0.94
  },
  "views": [
   {
    "id": "arms",
    "label": "Armrest",
    "yaw": 62,
    "pitch": 20,
    "distance": 1.3,
    "target": "arm"
   },
   {
    "id": "backboard",
    "label": "Back board",
    "yaw": 168,
    "pitch": 12,
    "distance": 1.4,
    "target": "back"
   }
  ],
  "atmosphere": {
   "haze": 0.55,
   "scanlines": true,
   "vignette": true,
   "grid": true,
   "motes": 0.25
  },
  "occlusion": "xray",
  "background": "deep"
 },
 "animation": {
  "assembly": {
   "style": "ceremony",
   "seconds": 7.0,
   "interference": true
  },
  "idle": {
   "life": "alive",
   "events": [
    "scan",
    "sweep",
    "shimmer"
   ],
   "cadence": [
    6,
    12
   ],
   "strength": 0.55
  },
  "camera": {
   "drift": 5,
   "breathe": 0.03,
   "tour": [
    {
     "view": "arms",
     "at": 13,
     "fly": 3.0
    },
    {
     "view": "hero",
     "at": 21,
     "fly": 3.5
    }
   ]
  },
  "reduced_motion": "still"
 },
 "authoring": {
  "tier": "masterpiece",
  "research": "done",
  "sources": [
   "request",
   "moma",
   "plan",
   "parts",
   "photos"
  ],
  "review_rounds": 4,
  "outcome": "good",
  "identity": [
   {
    "feature": "the two leaning planes: a blue seat carried between the frames and a red back board standing behind it",
    "parts": [
     "seat",
     "back"
    ],
    "source": "photos"
   },
   {
    "feature": "a lattice of 30 x 30 battens whose cut ends stand proud and are painted yellow",
    "parts": [
     "leg-front",
     "leg-rear",
     "runner",
     "cross-low-front",
     "cross-arm-rear",
     "arm"
    ],
    "source": "photos"
   },
   {
    "feature": "armrests on boards that cantilever past their post and land on the rear legs",
    "parts": [
     "arm",
     "post-arm"
    ],
    "source": "parts"
   }
  ],
  "next": [
   "express the joints as laps and wooden pins, not butted boxes",
   "settle the seat-to-back gap against a measured side elevation",
   "try the cutting list's 330 mm board against this 400 mm one from a rear view"
  ],
  "provenance_note": "Overall size and seat height are MoMA's measured figures; member sections and the 450 x 360 seat come from the cutting list; the member layout is traced from the dimensioned drawing; the back board's width and its foot position are read from the user's photographs; the board's rake is fitted so the published height and depth hold together.",
  "critic": {
   "scene_sha256": "0e40a7696268e8f2ec3c294b9785dd85e2ef8c2541a4348a2799aff04a05a4f4",
   "verdict": "good",
   "scores": {
    "silhouette": 2,
    "proportions": 2,
    "identity": 2,
    "depth": 2,
    "composition": 3,
    "assembly": 3,
    "motion": 2,
    "density": 2,
    "honesty": 3
   },
   "round": 6,
   "defects": 10
  },
  "rounds": [
   {
    "round": 1,
    "result": "baseline",
    "minutes": 0.5,
    "changes": [],
    "summary": "The seat board is rotated 90 deg in plan. It is built 360 mm across the chair and 460 mm deep; the cutting list's 450 mm side belongs across"
   },
   {
    "round": 2,
    "result": "kept",
    "minutes": 1.6,
    "changes": [
     "D1",
     "D3",
     "D5",
     "D6"
    ],
    "summary": "No joint is expressed as a joint. The arm's front end is a plain square-cut box (hero, view-arms) where the Montreal close-up shows a face o"
   },
   {
    "round": 3,
    "result": "kept",
    "minutes": 2.3,
    "changes": [
     "D3",
     "D5",
     "D8",
     "D9"
    ],
    "summary": "The back board is 880 mm long on an 838/867 mm chair. In still-side its lower edge descends past the low rear rail and converges on the rear"
   },
   {
    "round": 4,
    "result": "kept",
    "minutes": 2.3,
    "changes": [
     "D12",
     "D13",
     "D14",
     "D16"
    ],
    "summary": "The slot between the seat and the armrest is too small. In still-front the arm's top edge is 136 px above the seat's top edge in a 628 px hi"
   },
   {
    "round": 5,
    "result": "kept",
    "minutes": 0.4,
    "changes": [
     "D17",
     "D3"
    ],
    "summary": "The seat plane is too shallow for the frame it sits in. In still-side the seat's rear edge ends at x=696 while the back board's face is at x"
   },
   {
    "round": 6,
    "result": "kept",
    "minutes": 0.6,
    "changes": [
     "D18"
    ],
    "summary": "The seat plane rides too high in the frame. In still-front the arm's top edge is 102 px above the seat's top edge in a 577 px chair - 0.177 "
   }
  ]
 }
}