{"params":{"colorway":{"type":"choice","default":"red-oxide","label":"Colorway","describe":"Curated scheme matching the kit's track colourways, so the bridge joins the plain track the buyer laid. red-oxide (default, the kit concept's line): a tan ballast bed under grey sleepers, on warm light stone abutments with pale dressed copings. grey-ballast: grey running-line ballast under dark brown sleepers on the same stone. harvest: buff ballast under dark brown sleepers on light grey stone. limestone: pale limestone ballast and grey sleepers on light stone with off-white copings. cinder: brown cinder ballast and near-black creosoted sleepers on tan sandstone. taupe-stone: the Stone Viaduct Span's default, so a girder span set into a viaduct run matches it: grey-taupe walling under buff copings, a brown bed, dark sleepers, dark rails and trough ledges. Every scheme name shared with the viaduct gives the same walling and copings. The girder paint is the separate Paint knob; rails, rust and primer are the same in all five.","options":["red-oxide","grey-ballast","harvest","limestone","cinder","taupe-stone"]},"paint":{"type":"choice","default":"red-oxide","label":"Paint","describe":"Which coat the steelwork wears: red-oxide (default, the kit concept's red-brown oxide), grey (a dark charcoal grey) or dark-green (a deep olive company green). Changes the colour of the girders, stiffeners, gussets and cross girders only; the primer flakes, rust, grey trough ledges, stone and track are the same under all three.","options":["grey","dark-green","red-oxide"]},"length":{"type":"range","default":12,"label":"Length","describe":"Length of the piece along +z in metres: 8, 12 or 16 (other values snap), whole 4 m modules from z = 0. Rebuilds the span: the girder section, abutments and track section stay fixed while the stiffener panels repeat (6, 8 or 10 per girder at about 1.2-1.5 m), cross girders follow every other stiffener, sleepers repeat at the kit's 0.8 m pitch and the open span between the abutments grows from about 5.6 to 13.6 m.","affects":"geometry","min":8,"max":16,"step":4},"height":{"type":"range","default":4,"label":"Height","describe":"How far the ground the bridge spans lies below the track formation, in metres: 4, 8, 12 or 16 (other values snap). The stone abutments reach down to y = -height on a footing course; their battered gap faces lean out further the taller they are (a wider foot), while the girders, copings, bed courses and track stay put. 4 m clears a lane or a brook, 8 m a deep valley; 8, 12 and 16 m are the Stone Viaduct Span's heights, so a girder span drops into a viaduct run between its arches (the girder ends over the abutment meet the viaduct's half pier on the joint plane).","affects":"geometry","min":4,"max":16,"step":4},"wear":{"type":"range","default":0.3,"label":"Wear","describe":"0 freshly painted and new, 1 old and weathered: faded paint, dirt, rust and small chips; the object itself never changes.","affects":"geometry","min":0,"max":1,"step":0.1},"oxide":{"type":"color","default":"#774034","label":"Red-oxide paint","describe":"Albedo of all the painted steelwork when Paint is red-oxide: girder webs, flanges, flange angles, stiffener ribs, end posts, knee gussets and cross girders. Fades toward a chalky warm grey above wear 0.3."},"grey":{"type":"color","default":"#3f4140","label":"Grey paint","describe":"Albedo of the same painted steelwork when Paint is grey. Fades toward a chalky warm grey above wear 0.3."},"green":{"type":"color","default":"#63662c","label":"Green paint","describe":"Albedo of the same painted steelwork when Paint is dark-green. Fades toward a weathered grey-green above wear 0.3."},"undercoat":{"type":"color","default":"#a6714a","label":"Primer (flakes)","describe":"Albedo of the orange red-lead primer that shows where the top coat has flaked off the girder webs, in ragged patches lifting from a stiffener edge: one on each girder from wear 0.1, a second from 0.6. None at wear 0."},"rust":{"type":"color","default":"#896038","label":"Rust","describe":"Albedo of rusted steel: streaks hanging from the top rivet line (from wear 0.2) and patches rising from the girder foot (from 0.45) cut into the webs, then the girder bottoms (bottom flanges and bottom flange angles) from 0.5, cross girders and trough underside from 0.6 and the top rivet lines from 0.85. The colour old rail sides and ledges brown toward."},"stone":{"type":"color","default":"#ae9f8a","label":"Walling stone","describe":"Albedo of the abutment walling: the joint faces round the girder ends (the backwall under the trough and the fillers beside the girders), the wing walls and the battered gap face. Dirties a little toward brown above wear 0.3."},"dressings":{"type":"color","default":"#dfddd8","label":"Dressed stone","describe":"Albedo of the dressed stone: the bed course each girder end bears on, the sloping coping slabs on the wing walls and the footing course along each abutment foot. Dirties a little above wear 0.3."},"ballast":{"type":"color","default":"#af8361","label":"Ballast","describe":"Albedo of the ballast bed in the trough, laid to the kit track crest so plain track butts on. Darkens toward brown grime above wear 0.3."},"timber":{"type":"color","default":"#968d84","label":"Sleepers","describe":"Albedo of the timber sleepers. Greys toward silvered timber above wear 0.3."},"steel":{"type":"color","default":"#7c766b","label":"Rail and trough steel","describe":"Albedo of the unpainted steel: the rail head sides, webs, feet and cut ends, and the grey trough ledges with their lips along each girder. Above wear 0.3 it browns toward the rust colour, rail webs and feet hardest."},"bright":{"type":"color","default":"#ede9e0","label":"Running tops","describe":"Albedo of the polished running surface along the top of each rail. Wear never touches it."}},"presets":{"red-oxide":{"ballast":"#af8361","timber":"#968d84","stone":"#ae9f8a","dressings":"#dfddd8","oxide":"#774034","grey":"#3f4140","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#7c766b","bright":"#ede9e0"},"grey-ballast":{"ballast":"#968d84","timber":"#563e26","stone":"#ae9f8a","dressings":"#dfddd8","oxide":"#774034","grey":"#3f4140","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#7c766b","bright":"#ede9e0"},"harvest":{"ballast":"#ae9f8a","timber":"#563e26","stone":"#968d84","dressings":"#dfddd8","oxide":"#774034","grey":"#3f4140","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#7c766b","bright":"#ede9e0"},"limestone":{"ballast":"#dfddd8","timber":"#968d84","stone":"#ae9f8a","dressings":"#f2f2ec","oxide":"#774034","grey":"#3f4140","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#7c766b","bright":"#ede9e0"},"cinder":{"ballast":"#715f50","timber":"#2d2925","stone":"#af8361","dressings":"#ae9f8a","oxide":"#774034","grey":"#3f4140","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#7c766b","bright":"#ede9e0"},"taupe-stone":{"ballast":"#715f50","timber":"#563e26","stone":"#968d84","dressings":"#ae9f8a","oxide":"#774034","grey":"#7c766b","green":"#63662c","undercoat":"#a6714a","rust":"#896038","steel":"#3f4140","bright":"#ede9e0"}},"decals":[{"name":"girder-plate-right","size":[0.6,0.9],"at":[1.93,0.015,2.13],"normal":[1,0,0],"up":[0,1,0],"describe":"the second stiffener panel of the right-hand (+x) girder web from z = 0, clear of the wing wall, between the flange angles","albedo":"#774034","mode":"plate","relief_mm":0,"verified":true},{"name":"girder-plate-left","size":[0.6,0.9],"at":[-1.93,0.015,2.13],"normal":[-1,0,0],"up":[0,1,0],"describe":"the second stiffener panel of the left-hand (-x) girder web from z = 0, clear of the wing wall, between the flange angles","albedo":"#774034","mode":"plate","relief_mm":0,"verified":true}],"materials":{"oxide":{"kind":"paint","finish":"matte"},"grey":{"kind":"paint","finish":"matte"},"green":{"kind":"paint","finish":"matte"},"undercoat":{"kind":"paint","finish":"matte"},"rust":{"kind":"metal","finish":"rusted"},"stone":{"kind":"stone","finish":"rough"},"dressings":{"kind":"stone","finish":"rough"},"ballast":{"kind":"stone","finish":"rough"},"timber":{"kind":"wood","finish":"raw"},"steel":{"kind":"metal","finish":"satin"},"bright":{"kind":"metal","finish":"polished"}},"rev":1792605618,"materials_note":"what each colour zone is made of: `kind` and `finish` name a procedural PBR material in https://polyfork.dev/materials.mjs (dressByAlbedo finds a zone by its albedo in COLOR_0). A zone not listed has not been classified.","decals_note":"flat areas on the surface where you can print your own logo, sign or number. `at` is the centre in model space, `normal` points out of the surface, `size` is [width, height] in metres. Bake art with https://polyfork.dev/cdn/sdf.mjs and place it with https://polyfork.dev/cdn/decal.mjs, or use `at`/`normal`/`size` directly in any engine. `albedo` is the colour it prints on. mode `plate` means the face is flat and a quad is enough; `projected` means it is curved (`relief_mm` deep) and the mark has to be projected onto the geometry. Measured on the DEFAULT build: a geometry knob can move the surface a few centimetres; decal.mjs follows it, anywhere else re-measure or keep the defaults.","preview_v":1792606029,"mod_v":1792605618}