We are building frontierfoundation models for 3D.Building frontierfoundation modelsfor 3D.

"""Fauteuil de bureau ergonomique, construit pièce par pièce.
blender -b -P chaise.py -- <sortie_dir> [vues...] [--samples N] [--res WxH]
Repère : X largeur, -Y avant, Z haut.
"""
import sys, os, math
sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), 'lib'))
import bpy
from mathutils import Vector
import studio as S
from studio import PI, M

S.reset()
P = S.palette()
mesh_fab = S.mat_mesh_fabric('Maille', (0.014, 0.015, 0.017), scale=32)
mesh_fab.node_tree.nodes['Principled BSDF'].inputs['Specular IOR Level'].default_value = 0.25
cushion_mat = S.mat('TissuRouge', (0.40, 0.012, 0.010), 0.0, 0.72, noise=0.06)
arm_pu = S.mat('PolyurethaneNoir', (0.014, 0.014, 0.016), 0.0, 0.55, noise=0.12)
cushion_mat.node_tree.nodes['Principled BSDF'].inputs['Specular IOR Level'].default_value = 0.22
S.add_weave_bump(cushion_mat, 420, 0.22)

# ---------------------------------------------------------------- piètement
HUB_Z = 0.125
LEG_R = 0.335
legs = []
for i in range(5):
    keys = []
    for k in range(7):
        t = k / 6
        x = 0.035 + t * (LEG_R - 0.035)
        z = HUB_Z + 0.008 - t * 0.032 + 0.012 * math.sin(t * PI)       # légère cambrure
        w = 0.030 - 0.011 * t
        h = 0.030 - 0.010 * t
        keys.append((x, 0, z, w, h, 3.2))
    me = S.loft('branche', S.smooth_sections(keys, 4), n=32)
    legs.append((me, M(rot=(0, 0, 2 * PI * i / 5 + PI / 2))))
hub = S.lathe('moyeu', [(0, HUB_Z - 0.035), (0.040, HUB_Z - 0.035), (0.048, HUB_Z - 0.01),
                        (0.048, HUB_Z + 0.025), (0.036, HUB_Z + 0.04), (0, HUB_Z + 0.04)], 64)
legs.append((hub, M()))
S.part('Piètement', S.join_meshes('pietement', legs), P['alu'], 'base',
       explode=(0, 0, -0.18), bevel=0.003, label='5-star base')

# embouts sous les branches + roulettes jumelées
W_R, W_T = 0.034, 0.017                   # rayon et largeur d'une roue
caster_hub = S.mat('MoyeuGris', (0.10, 0.105, 0.11), 0.0, 0.35, coat=0.4)
for i in range(5):
    a = 2 * PI * i / 5 + PI / 2
    tip = Vector((math.cos(a) * (LEG_R - 0.012), math.sin(a) * (LEG_R - 0.012), 0))
    out = Vector((math.cos(a), math.sin(a), 0))
    side = out.cross(Vector((0, 0, 1)))       # axe des roues, perpendiculaire à la branche
    S.part(f'Embout{i}', S.lathe('embout', [(0, 0), (0.017, 0), (0.019, 0.004), (0.019, 0.028), (0, 0.028)], 32),
           P['black'], 'base', loc=tip + Vector((0, 0, HUB_Z - 0.05)), explode=(0, 0, -0.18), bevel=0.002)
    ex = out * 0.10 + Vector((0, 0, -0.30))
    axle = tip + out * 0.024 + Vector((0, 0, W_R))
    wrot = (PI / 2, 0, a)                     # Z local -> axe des roues ; Y local -> haut ; X local -> extérieur
    GAP = 0.020                               # largeur du corps central entre les deux roues
    # corps central (moyeu) + carénage supérieur qui mord sur le haut des roues
    S.part(f'Corps{i}', S.lathe('corps', [(0, -GAP / 2), (W_R - 0.010, -GAP / 2), (W_R - 0.007, -GAP / 2 + 0.003),
                                           (W_R - 0.007, GAP / 2 - 0.003), (W_R - 0.010, GAP / 2), (0, GAP / 2)], 48),
           P['black_gloss'], 'roulettes', loc=axle, rot=wrot, explode=ex + Vector((0, 0, 0.04)),
           label='Twin-wheel casters · 25 parts')
    half = GAP / 2 + W_T * 0.72
    fair = [(W_R - 0.006, -half), (W_R + 0.004, -half), (W_R + 0.0065, -half + 0.004), (W_R + 0.0075, -GAP / 2),
            (W_R + 0.008, 0.0), (W_R + 0.0075, GAP / 2), (W_R + 0.0065, half - 0.004), (W_R + 0.004, half),
            (W_R - 0.006, half)]
    o = S.part(f'Carénage{i}', S.lathe('carenage', fair, 48, angle=PI * 0.92, start=PI * 0.04), P['black_gloss'],
               'roulettes', loc=axle, rot=wrot, explode=ex + Vector((0, 0, 0.04)))
    sol = o.modifiers.new('ep', 'SOLIDIFY'); sol.thickness = 0.0022; sol.offset = 1
    # col : pivot vertical posé sur le carénage
    S.part(f'Col{i}', S.lathe('col', [(0, 0), (0.0115, 0), (0.0125, 0.004), (0.0095, 0.016), (0.0085, 0.022), (0, 0.022)], 32),
           P['black_gloss'], 'roulettes', loc=axle + Vector((0, 0, W_R + 0.004)) - out * 0.010,
           explode=ex + Vector((0, 0, 0.04)), bevel=0.001)
    S.part(f'Pivot{i}', S.cyl('pivot', 0.0055, 0.030), P['chrome'], 'roulettes',
           loc=axle + Vector((0, 0, W_R + 0.034)) - out * 0.010, explode=ex + Vector((0, 0, 0.08)))
    for sgn in (-1, 1):
        wc = axle + side * (sgn * (GAP / 2 + W_T / 2 + 0.001))
        tire = [(W_R - 0.008, -W_T / 2), (W_R - 0.003, -W_T / 2), (W_R - 0.0008, -W_T / 2 + 0.003),
                (W_R, -W_T / 2 + 0.006), (W_R, W_T / 2 - 0.006), (W_R - 0.0008, W_T / 2 - 0.003),
                (W_R - 0.003, W_T / 2), (W_R - 0.008, W_T / 2), (W_R - 0.008, -W_T / 2)]
        S.part(f'Bandage{i}{sgn}', S.lathe('bandage', tire, 64), P['rubber'], 'roulettes', loc=wc, rot=wrot,
               explode=ex + side * sgn * 0.05)
        hub = [(0.004, -W_T / 2 + 0.001), (W_R - 0.008, -W_T / 2 + 0.001), (W_R - 0.008, W_T / 2 - 0.001),
               (0.020, W_T / 2 - 0.001), (0.017, W_T / 2 - 0.003), (0.004, W_T / 2 - 0.003)]
        if sgn < 0:                                # face creusée toujours vers l'extérieur
            hub = [(r, -z) for r, z in hub]
        S.part(f'Jante roulette{i}{sgn}', S.lathe('jr', hub, 64), caster_hub, 'roulettes', loc=wc, rot=wrot,
               explode=ex + side * sgn * 0.05, bevel=0.0008, segs=2)
        S.part(f'Enjoliveur{i}{sgn}', S.lathe('enj', [(0, 0), (0.0145, 0), (0.0155, 0.0012), (0.013, 0.003), (0, 0.0035)], 48),
               P['chrome'], 'roulettes', loc=wc + side * (sgn * (W_T / 2 - 0.0032)), rot=(sgn * PI / 2, 0, a),
               explode=ex + side * sgn * 0.08)

# ---------------------------------------------------------------- vérin
S.part('Fourreau', S.lathe('fourreau', [(0, 0.06), (0.036, 0.06), (0.036, 0.165), (0.033, 0.17),
                                        (0.033, 0.215), (0.030, 0.22), (0.030, 0.27), (0.027, 0.275), (0, 0.275)], 64),
       P['black_gloss'], 'verin', explode=(0, 0, -0.08), bevel=0.002, label='Gas lift · 3 parts')
S.part('Piston', S.lathe('piston', [(0, 0.27), (0.0215, 0.27), (0.0215, 0.385), (0.025, 0.39),
                                     (0.025, 0.405), (0, 0.405)], 64),
       P['chrome'], 'verin', explode=(0, 0, 0.0))
S.part('Bague', S.tube_ring('bague', 0.03, 0.0215, 0.012), P['alu'], 'verin',
       loc=(0, 0, 0.283), explode=(0, 0, -0.04), bevel=0.002)

# ---------------------------------------------------------------- mécanisme
MZ = 0.43
o = S.part('Mécanisme', S.shaped_box('meca', 0.20, 0.25, 0.045, 3,
                                     lambda q: Vector((q.x * (1 - 0.12 * max(0.0, -q.y / 0.125)), q.y, q.z))),
           P['alu_dark'], 'meca', loc=(0, 0.01, MZ), label='Synchro mechanism · 18 parts')
S.soften(o, 0.010, 2)
S.part('Platine', S.box('platine', 0.27, 0.30, 0.008), P['steel'], 'meca',
       loc=(0, 0, MZ + 0.027), explode=(0, 0, 0.05), bevel=0.003)
S.part('Bouton tension', S.lathe('bt', [(0, 0), (0.022, 0), (0.024, 0.004), (0.024, 0.026),
                                           (0.020, 0.03), (0, 0.03)], 24),
       P['black'], 'meca', loc=(0, -0.125, MZ - 0.012), rot=(PI / 2, 0, 0), explode=(0, -0.12, 0), bevel=0.002)
S.part('Tige tension', S.cyl('tt', 0.006, 0.04), P['chrome'], 'meca',
       loc=(0, -0.11, MZ - 0.012), rot=(PI / 2, 0, 0), explode=(0, -0.08, 0))
S.part('Levier', S.curve_tube('levier', [(0.10, -0.02, MZ - 0.005), (0.16, -0.03, MZ - 0.01),
                                          (0.19, -0.07, MZ - 0.02), (0.20, -0.12, MZ - 0.025)], 0.0045),
       P['chrome'], 'meca', explode=(0.12, 0, 0))
S.part('Poignée levier', S.loft('pl', S.smooth_sections([
    (0.0, 0, 0, 0.006, 0.006, 2), (0.02, 0, 0, 0.012, 0.009, 2.5), (0.045, 0, 0, 0.011, 0.008, 2.5),
    (0.05, 0, 0, 0.004, 0.004, 2)], 4), n=24),
       P['black'], 'meca', loc=(0.20, -0.115, MZ - 0.025), rot=(0, 0, -PI / 2), explode=(0.12, 0, 0))

# ---------------------------------------------------------------- assise
SZ = MZ + 0.04
SEAT_A, SEAT_B, SEAT_H = 0.250, 0.240, 0.075
o = S.part('Coque assise', S.cushion('coque', 0.246, 0.232, 0.024, 5.0, 0.008, 0.006, 0.0), P['black'], 'assise',
           loc=(0, -0.012, SZ + 0.010), explode=(0, 0, 0.14), label='Seat · shell + cushion')


def seat_shape(p):
    """Assise sculptée : bourrelets latéraux, creux fessier, bord avant en cascade, avant plus étroit."""
    x, y, z = p
    if z > 0:
        t = min(1.0, z / (SEAT_H / 2))                          # 0 au plan médian, 1 sur le dessus
        dz = 0.022 * (abs(x) / SEAT_A) ** 3                     # bourrelets
        dz -= 0.016 * math.exp(-((x / 0.13) ** 2 + ((y - 0.03) / 0.12) ** 2))   # creux
        dz -= 0.024 * max(0.0, (-y - 0.12) / 0.12) ** 2         # cascade avant
        dz += 0.005 * max(0.0, (y - 0.12) / 0.12)               # arrière relevé
        z += dz * t
    x *= 1.0 - 0.05 * max(0.0, -y / SEAT_B)
    return Vector((x, y, z))


SEAT_C = Vector((0, -0.015, SZ + 0.055))
S.part('Coussin', S.cushion('coussin', SEAT_A, SEAT_B, SEAT_H, 4.2, 0.030, 0.010, 0.004, 128, seat_shape),
       cushion_mat, 'assise', loc=SEAT_C, explode=(0, 0, 0.30))
seam_m = S.mat('Couture', (0.16, 0.006, 0.005), 0.0, 0.8)
# passepoil sur l'arrondi supérieur
pp = S.cushion_ring(SEAT_A, SEAT_B, SEAT_H, 0.030, 4.2, 128, 0.62, seat_shape)
S.part('Passepoil', S.curve_tube('pp', [SEAT_C + q for q in pp], 0.0034, closed=True, res=2, bevel_res=3),
       cushion_mat, 'assise', explode=(0, 0, 0.30))
# piqûres : deux sillons longitudinaux + une traverse, posés dans la mousse
for xs in (-0.092, 0.092):
    pts = [SEAT_C + seat_shape(Vector((xs, -0.20 + 0.36 * k / 20, SEAT_H / 2))) - Vector((0, 0, 0.0015)) for k in range(21)]
    S.part(f'Couture{xs:+.2f}', S.curve_tube('cou', pts, 0.0026, res=4), seam_m, 'assise', explode=(0, 0, 0.30))
pts = [SEAT_C + seat_shape(Vector((-0.092 + 0.184 * k / 20, 0.16, SEAT_H / 2))) - Vector((0, 0, 0.0015)) for k in range(21)]
S.part('Couture arrière', S.curve_tube('cou', pts, 0.0026, res=4), seam_m, 'assise', explode=(0, 0, 0.30))

# ---------------------------------------------------------------- dossier
BY, BZ, BH = 0.24, SZ + 0.13, 0.56
REC = math.radians(14)


def back_surf(u, v, inset=0.0):
    """u ∈ [-1,1] largeur, v ∈ [0,1] hauteur ; renvoie un point du dossier galbé."""
    half = 0.215 + 0.035 * math.sin(v * PI) - 0.03 * v
    x = u * (half - inset)
    lumbar = 0.028 * math.exp(-((v - 0.22) / 0.16) ** 2)
    vv = v * (1 - 2 * inset / BH) + inset / BH
    y = BY + vv * BH * math.sin(REC) - lumbar - 0.06 * (u * (1 - inset)) ** 2
    z = BZ + vv * BH * math.cos(REC)
    return Vector((x, y, z))


outline = []
for k in range(72):
    t = 2 * PI * k / 72
    u, v = S.superellipse(t, 1.0, 0.5, 5)
    outline.append(back_surf(u, v + 0.5))
# cadre sculpté : profil ovale aplati, plus épais sur les flancs (là où passe l'effort), affiné en haut et en bas
outline = []
for k in range(160):
    t = 2 * PI * k / 160
    u, v = S.superellipse(t, 1.0, 0.5, 5)
    outline.append(back_surf(u, v + 0.5))
frame_taper = lambda i, m: 0.78 + 0.30 * abs(math.cos(2 * PI * i / m))
S.part('Cadre dossier', S.sweep('cadre', outline, 0.020, 0.014, 2.6, up=(0, math.cos(REC), -math.sin(REC)),
                                closed=True, n=28, taper=frame_taper),
       P['black_gloss'], 'dossier', explode=(0, 0.30, 0.18), label='Backrest · frame + mesh')
NU, NV = 40, 40
vs, fs = [], []
for j in range(NV + 1):
    for i in range(NU + 1):
        u = -1 + 2 * i / NU
        v = j / NV
        uu, vv = u, v - 0.5
        # rétrécit la grille dans le contour superellipse
        lim = (1 - abs(2 * vv) ** 5) ** (1 / 5) if abs(2 * vv) < 1 else 0
        vs.append(back_surf(uu * lim * 0.985, 0.5 + vv * 0.985))
for j in range(NV):
    for i in range(NU):
        a = j * (NU + 1) + i
        fs.append((a, a + 1, a + NU + 2, a + NU + 1))
mm = S.mesh_from('maille', vs, fs)
uvl = mm.uv_layers.new()
for poly in mm.polygons:
    for li in poly.loop_indices:
        vi = mm.loops[li].vertex_index
        uvl.data[li].uv = ((vi % (NU + 1)) / NU, (vi // (NU + 1)) / NV)
o = S.part('Maille', mm, mesh_fab, 'dossier', explode=(0, 0.30, 0.18))
sol = o.modifiers.new('Ep', 'SOLIDIFY'); sol.thickness = 0.002
# support lombaire : coussinet derrière la maille, glissières sur le cadre
lv = 0.24
lsec = []
for k in range(13):
    u = -0.80 + 1.60 * k / 12
    q = back_surf(u, lv) + Vector((0, 0.024, 0))
    lsec.append((q.x, q.y, q.z, 0.011, 0.042 * (1 - 0.35 * abs(u) ** 4), 3.0))
S.part('Lombaire', S.loft('lombaire', lsec, n=24), P['black'], 'dossier', explode=(0, 0.48, 0.14))
for sgn in (-1, 1):
    S.part(f'Curseur lombaire{sgn}', S.box('cl', 0.026, 0.03, 0.06), P['alu_dark'], 'dossier',
           loc=back_surf(sgn * 0.99, lv) + Vector((0, 0.012, 0)), rot=(REC, 0, 0),
           explode=(0, 0.48, 0.14), bevel=0.007)
# colonne : du mécanisme vers l'arrière du dossier, puis fourche (Y) jusqu'aux flancs du cadre
spine = [(0, 0.10, MZ - 0.005), (0, 0.20, MZ - 0.012), (0, 0.30, MZ + 0.03),
         tuple(back_surf(0, 0.02) + Vector((0, 0.075, 0.0))), tuple(back_surf(0, 0.12) + Vector((0, 0.07, 0)))]
S.part('Colonne', S.curve_tube('colonne', spine, 0.021, res=32), P['alu'], 'colonne',
       explode=(0, 0.20, -0.02), label='Back spine + yoke')
yoke_root = back_surf(0, 0.12) + Vector((0, 0.07, 0))
for sgn in (-1, 1):
    arm = [tuple(yoke_root), tuple(back_surf(sgn * 0.45, 0.22) + Vector((0, 0.065, 0))),
           tuple(back_surf(sgn * 0.88, 0.40) + Vector((0, 0.04, 0))),
           tuple(back_surf(sgn * 1.0, 0.50) + Vector((0, 0.012, 0)))]
    S.part(f'Fourche{sgn}', S.curve_tube('fourche', arm, 0.014, res=32), P['alu'], 'colonne',
           explode=(sgn * 0.06, 0.20, 0.0))
    S.part(f'Rotule{sgn}', S.lathe('rot', [(0, -0.018), (0.016, -0.018), (0.02, -0.006), (0.02, 0.006),
                                           (0.016, 0.018), (0, 0.018)], 32), P['alu_dark'], 'colonne',
           loc=back_surf(sgn * 1.0, 0.50) + Vector((0, 0.03, 0)), rot=(0, PI / 2, 0),
           explode=(sgn * 0.06, 0.20, 0.0), bevel=0.002)
S.part('Bride colonne', S.lathe('bride', [(0, -0.03), (0.032, -0.03), (0.036, -0.02), (0.036, 0.02),
                                          (0.032, 0.03), (0, 0.03)], 48), P['alu_dark'], 'colonne',
       loc=yoke_root, rot=(PI / 2 + REC, 0, 0), explode=(0, 0.20, 0.0), bevel=0.003)

# ---------------------------------------------------------------- accoudoirs
for sgn in (-1, 1):
    ex = (sgn * 0.22, 0, 0.05)
    bar = [(sgn * 0.09, 0.04, MZ - 0.005), (sgn * 0.20, 0.04, MZ - 0.008), (sgn * 0.27, 0.05, MZ + 0.01),
           (sgn * 0.285, 0.06, MZ + 0.06)]
    S.part(f'Bras support{sgn}', S.curve_tube('bras', bar, 0.013, res=24), P['alu'], 'accoudoirs',
           explode=ex, label='4D armrests · 10 parts')
    o = S.part(f'Fût{sgn}', S.shaped_box('fut', 0.032, 0.056, 0.20, 2), P['black'], 'accoudoirs',
               loc=(sgn * 0.285, 0.06, MZ + 0.15), explode=ex)
    S.soften(o, 0.009, 2)
    o = S.part(f'Fourreau accoudoir{sgn}', S.shaped_box('fa', 0.038, 0.062, 0.09, 2), P['black_gloss'], 'accoudoirs',
               loc=(sgn * 0.285, 0.06, MZ + 0.105), explode=ex)
    S.soften(o, 0.010, 2)
    S.part(f'Bouton hauteur{sgn}', S.box('bh', 0.012, 0.03, 0.04), P['alu_dark'], 'accoudoirs',
           loc=(sgn * 0.285, 0.029, MZ + 0.19), explode=(sgn * 0.22, -0.06, 0.05), bevel=0.004)
    o = S.part(f'Platine accoudoir{sgn}', S.shaped_box('pa', 0.056, 0.20, 0.012, 2), P['alu_dark'], 'accoudoirs',
               loc=(sgn * 0.285, 0.04, MZ + 0.255), explode=(sgn * 0.22, 0, 0.12))
    S.soften(o, 0.004, 2)
    arm_fn = lambda q: Vector((q.x, q.y, q.z + (0.004 * (1 - (q.x / 0.125) ** 2) if q.z > 0 else 0)))
    S.part(f'Manchette{sgn}', S.cushion('pad', 0.125, 0.040, 0.030, 3.6, 0.012, 0.005, 0.002, 96, arm_fn),
           arm_pu, 'accoudoirs', loc=(sgn * 0.285, 0.03, MZ + 0.277), rot=(0, 0, PI / 2), explode=(sgn * 0.22, 0, 0.20))

# ---------------------------------------------------------------- appui-tête
top = back_surf(0, 1.0)
S.part('Glissière appui-tête', S.box('gat', 0.05, 0.022, 0.16), P['alu_dark'], 'tete',
       loc=back_surf(0, 0.88) + Vector((0, 0.03, 0)), rot=(REC, 0, 0), explode=(0, 0.16, 0.22), bevel=0.006,
       label='Headrest · 3 parts')
stem = [tuple(back_surf(0, 0.86) + Vector((0, 0.04, 0))), tuple(top + Vector((0, 0.045, 0.02))),
        tuple(top + Vector((0, 0.02, 0.085)))]
stem = [back_surf(0, 0.84) + Vector((0, 0.042, 0)), back_surf(0, 0.97) + Vector((0, 0.05, 0.0)),
        top + Vector((0, 0.045, 0.05)), top + Vector((0, 0.025, 0.10))]
stem = [stem[0].lerp(stem[1], t / 6) if t <= 6 else None for t in range(7)][:-1] +        [stem[1].lerp(stem[2], t / 6) for t in range(6)] + [stem[2].lerp(stem[3], t / 6) for t in range(7)]
S.part('Lame appui-tête', S.sweep('lame', stem, 0.008, 0.026, 4.0, up=(0, 1, 0), n=24), P['alu'], 'tete',
       explode=(0, 0.16, 0.30))


def head_shape(p):
    """Repère local du coussin : x largeur, y hauteur, z épaisseur (+z = face avant une fois tourné)."""
    x, y, z = p
    z += 0.055 * (x / 0.15) ** 2                    # galbe enveloppant
    y *= 1.0 - 0.22 * (abs(x) / 0.15) ** 3          # oreilles affinées
    return Vector((x, y, z))


HEAD_C = top + Vector((0, 0.005, 0.135))
HEAD_R = (PI / 2 + REC * 0.6, 0, 0)
S.part('Appui-tête', S.cushion('appui', 0.150, 0.060, 0.052, 4.0, 0.020, 0.016, 0.003, 112, head_shape), cushion_mat,
       'tete', loc=HEAD_C, rot=HEAD_R, explode=(0, 0.16, 0.40))
ring = S.cushion_ring(0.150, 0.060, 0.052, 0.020, 4.0, 112, 0.62, head_shape)
o = S.part('Passepoil appui-tête', S.curve_tube('ppa', ring, 0.0030, closed=True, res=2, bevel_res=3), cushion_mat,
           'tete', loc=HEAD_C, rot=HEAD_R, explode=(0, 0.16, 0.40))

# ---------------------------------------------------------------- détails mécaniques
hexb = lambda nm: S.lathe(nm, [(0, 0), (0.0085, 0), (0.0085, 0.006), (0.0055, 0.0075), (0, 0.0075)], 6)
for ix in (-1, 1):
    for iy in (-1, 1):
        S.part(f'Vis platine{ix}{iy}', hexb('vis'), P['chrome'], 'meca',
               loc=(ix * 0.115, iy * 0.13, MZ + 0.031), explode=(ix * 0.03, iy * 0.03, 0.22), smooth=False)
# glissières d'assise
for sgn in (-1, 1):
    S.part(f'Glissière{sgn}', S.box('gl', 0.022, 0.34, 0.012), P['alu'], 'meca',
           loc=(sgn * 0.10, -0.01, MZ + 0.037), explode=(sgn * 0.02, 0, 0.10), bevel=0.003)
# axe de bascule traversant + carter de ressort
S.part('Axe bascule', S.cyl('axe', 0.009, 0.25), P['chrome'], 'meca', loc=(0, -0.06, MZ - 0.005),
       rot=(0, PI / 2, 0), explode=(0.0, -0.04, -0.06))
S.part('Carter ressort', S.lathe('cr', [(0, -0.07), (0.022, -0.07), (0.026, -0.064), (0.026, 0.064),
                                         (0.022, 0.07), (0, 0.07)], 48), P['black_gloss'], 'meca',
       loc=(0, -0.06, MZ - 0.02), rot=(0, PI / 2, 0), explode=(0, -0.06, -0.10), bevel=0.002)
for k in range(9):
    S.part(f'Spire{k}', S.torus('sp', 0.0265, 0.0028, 48, 8), P['steel'], 'meca',
           loc=(-0.056 + k * 0.014, -0.06, MZ - 0.02), rot=(0, PI / 2, 0), explode=(0, -0.06, -0.10))
# second levier (hauteur), côté gauche
S.part('Levier hauteur', S.curve_tube('lh', [(-0.10, 0.02, MZ - 0.005), (-0.17, 0.0, MZ - 0.012),
                                              (-0.205, -0.05, MZ - 0.02), (-0.21, -0.10, MZ - 0.022)], 0.0045),
       P['chrome'], 'meca', explode=(-0.12, 0, 0))
S.part('Poignée hauteur', S.lathe('ph', [(0, 0), (0.008, 0), (0.011, 0.01), (0.011, 0.035), (0.008, 0.045), (0, 0.045)], 24),
       P['black'], 'meca', loc=(-0.21, -0.10, MZ - 0.022), rot=(PI / 2, 0, 0), explode=(-0.12, 0, 0))
# nervures sous la coque d'assise
for k in range(5):
    S.part(f'Nervure{k}', S.box('nv', 0.44, 0.008, 0.014), P['black'], 'assise',
           loc=(0, -0.20 + k * 0.095, SZ - 0.005), explode=(0, 0, 0.14), bevel=0.002)
# collier décoratif du moyeu
S.part('Collier moyeu', S.torus('cm', 0.049, 0.004, 64, 10), P['chrome'], 'base',
       loc=(0, 0, HUB_Z + 0.022), explode=(0, 0, -0.18))
# plaque signature sur la bride
S.part('Plaque', S.box('plq', 0.05, 0.004, 0.018), P['chrome'], 'colonne',
       loc=back_surf(0, 0.12) + Vector((0, 0.103, 0.0)), rot=(REC, 0, 0), explode=(0, 0.26, 0.0), bevel=0.002)

# ---------------------------------------------------------------- rendus
outdir, views, samples, res, tag = S.args('chaise')
WAVES = [['base'], ['roulettes'], ['verin'], ['meca'], ['assise'], ['colonne', 'dossier'], ['accoudoirs'], ['tete']]
WAVE_NAMES = ['Base', 'Casters', 'Gas lift', 'Mechanism', 'Seat', 'Backrest', 'Armrests', 'Headrest']
PENDING = {'dossier', 'tete', 'accoudoirs', 'assise', 'roulettes'}

S.lights(center=(0, 0, 0.6), scale=1.0)
cam = S.camera((0, -3, 1), (0, 0, 0.5), lens=55)
objs = [p['obj'] for p in S.PARTS]
if views[0] == 'video':
    import assemble
    step = int(sys.argv[sys.argv.index('--step') + 1]) if '--step' in sys.argv else 1
    only = None if step == 1 else set(range(0, 100000, step))
    if '--range' in sys.argv:
        r0, r1 = map(int, sys.argv[sys.argv.index('--range') + 1].split('-'))
        only = set(range(r0, r1))
    assemble.render_video(os.path.join(outdir, 'video_' + tag), WAVES, WAVE_NAMES, (-1.0, -1.55, 0.42),
                          fill=0.82, samples=samples, res=res, only=only, total=770, exploded=1.0, ex_spin=False,
                          ex_focus=[dict(key='accoudoirs', match=r'-1$', yaw=-0.55, dist=1.2,
                                         title='4D armrests', sub='Height · width · depth · pivot'),
                                    dict(key='meca', dist=1.05,
                                         title='Synchro mechanism', sub='4-position tilt lock · tension knob'),
                                    dict(key='roulettes', yaw=-0.25, pitch=0.9, dist=0.62,
                                         match=r'^(Capot|Corps|Carénage|Col|Pivot|Bandage|Jante roulette|Enjoliveur)2(-1|1)?$',
                                         title='Twin-wheel casters', sub='Ø 68 mm · soft-floor PU tread')],
                          ex_close=1.05, ex_fstop=2.8, ex_wide=34, ex_snap=10, orbit=1, end_hold=0,
                          ex_labels={'base', 'assise', 'dossier', 'tete'},
                          # vue éclatée « logique » : pile verticale, dossier en arrière, accoudoirs sur les côtés
                          ex_groups={'base': (0, 0, -0.42), 'roulettes': (0, 0, -0.42), 'verin': (0, 0, -0.16),
                                     'meca': (0, 0, 0.0), 'assise': (0, 0, 0.24), 'colonne': (0, 0.20, 0.04),
                                     'dossier': (0, 0.38, 0.20), 'accoudoirs': (('side', 0.34), 0, 0.10),
                                     'tete': (0, 0.42, 0.55)})
    sys.exit(0)
a2 = 2 * PI * 2 / 5 + PI / 2
ZOOMS = {   # vues rapprochées fixes pour les planches avant | après
    'z_assise': (Vector((0.0, -0.08, SZ + 0.04)), Vector((-0.50, -0.80, 0.34)), 50),
    'z_roulette': (Vector((math.cos(a2) * LEG_R, math.sin(a2) * LEG_R, 0.05)), Vector((-0.20, -0.36, 0.12)), 60),
    'z_accoudoir': (Vector((-0.20, 0.02, MZ + 0.10)), Vector((-0.62, -0.78, 0.26)), 50),
    'z_dos': (Vector((0.0, 0.30, MZ + 0.30)), Vector((0.55, 0.95, 0.35)), 45),
}
for v in views:
    S.explode(0.0)
    cam.data.lens = 55
    if v in ZOOMS:
        tgt, off, lens = ZOOMS[v]
        cam.data.lens = lens
        cam.data.shift_x = cam.data.shift_y = 0
        cam.location = tgt + off
        S.look_at(cam, tgt)
    if v == 'hero':
        S.frame_camera(cam, objs, (-1.0, -1.55, 0.36), 0.86)
    elif v == 'side':
        S.frame_camera(cam, objs, (1.0, 0.05, 0.12), 0.84)
    elif v == 'back':
        S.frame_camera(cam, objs, (0.9, 1.3, 0.5), 0.84)
    elif v == 'explode':
        S.explode(1.0)
        S.frame_camera(cam, objs, (-1.0, -1.55, 0.55), 0.84)
    elif v == 'sketch':
        S.explode(0.7)
        S.frame_camera(cam, objs, (-1.0, -1.55, 0.55), 0.74)
        S.sketch_state(PENDING, 0.7)
    elif v == 'detail':
        cam.data.lens = 85
        cam.data.shift_x = cam.data.shift_y = 0
        tgt = back_surf(0.55, 0.12)
        cam.location = tgt + Vector((-0.55, -0.75, 0.22))
        S.look_at(cam, tgt)
    elif v == 'low':
        S.frame_camera(cam, objs, (-0.6, -1.6, -0.05), 0.84)
    S.render(os.path.join(outdir, f'{tag}_{v}.png'), samples, res)
    if v == 'sketch':
        S.export_labels(os.path.join(outdir, f'{tag}_{v}.json'))
        S.restore_materials()
S.explode(0.0)
S.save_blend(os.path.join(outdir, 'chaise.blend'))