Playground

asset ferris_wheel "Moonlight wheel" complexity=9
// the carnival's big wheel: a striped boarding deck, two splayed A-frames carrying a brass hub, a
// double rim of girders with glowing bulbs down every spoke and round the rims, and twelve
// bell-roofed gondolas that hang level while the wheel turns. A star tops the frame.
let R = 5.8..6.2
let H = R + 2.4
let frameC = white:3|cream|sky
let rimC = cherry:3|cobalt|grape|teal
let hubC = brass:3|copper
let deckC = navy:2|plum|bottle
let bulbA = glow:3|sunflower
let bulbB = pink:2|cherry|tangerine
let gA = cobalt:2|navy|grape
let gB = pink:2|tangerine|mint
 
// the boarding deck and steps
cyl deck h=.4 r=3.1 sq=6 depth=.62 round=.08 bands=[.55:deckC] color=frameC segs=28
box step on=deck at=(0, 0, 2.0) size=(2.2, .2, .7) round=.05 color=frameC
 
// two A-frames, front and back, meeting at the hub
rod leg x2 on=deck row=(0, 0, 2.5) at=(3.4, .12, 0) mirror to=(-3.4, H-.07, 0) r=(.17, .11) sides=8 bands=[.06:hubC .1:frameC] color=frameC
rod brace x2 on=deck row=(0, 0, 2.5) at=(-2.2, H*.35, 0) to=(4.4, 0, 0) r=.08 sides=6 color=frameC
cyl foot x2 on=deck row=(0, 0, 2.5) at=(3.4, 0, 0) mirror h=.3 r=.26 round=.06 color=hubC segs=10
cyl axle on=deck at=(0, H, -1.55) rot=(90, 0, 0) h=3.1 r=.2 round=.05 color=hubC segs=12
 
// the wheel: the turning bone, turned so its Y runs along the axle (y 0 = back, 1.7 = front)
cyl wheel on=deck at=(0, H, -.85) rot=(90, 0, 0) h=1.7 r=.62 round=.12 bands=[.2:hubC .8:rimC] color=hubC segs=20 joint
torus rim x2 on=wheel row=(0, 1.5, 0) at=(0, .85, 0) R=R r=.12 color=rimC segs=72 sides=8
torus inner x2 on=wheel row=(0, 1.38, 0) at=(0, .85, 0) R=R*.62 r=.075 color=frameC segs=48 sides=6
rod spoke x12 on=wheel ring at=(.55, .1, 0) to=(R-.55, 0, 0) r=(.09, .06) sides=6 color=frameC
rod spoke2 x12 on=wheel ring at=(.55, 1.6, 0) to=(R-.55, 0, 0) r=(.09, .06) sides=6 color=frameC
rod tie x12 on=wheel ring ring0=15 at=(R*.62, .2, 0) to=(0, 1.3, 0) r=.05 sides=5 color=frameC
ball bulb x3 on=spoke at=(R*.3-.55, -.1, 0) row=(R*.24, 0, 0) r=.14 color=sel(i, bulbA, bulbB, bulbA) ink=glow segs=8 rings=5
ball bulb2 x3 on=spoke2 at=(R*.3-.55, .1, 0) row=(R*.24, 0, 0) r=.14 color=sel(i, bulbB, bulbA, bulbB) ink=glow segs=8 rings=5
ball rimbulb x24 on=wheel ring ring0=7.5 at=(R, 1.76, 0) r=.15 color=sel(i - 2*floor(i/2), bulbA, bulbB) ink=glow segs=8 rings=5
ball rimbulb2 x24 on=wheel ring ring0=7.5 at=(R, -.06, 0) r=.15 color=sel(i - 2*floor(i/2), bulbB, bulbA) ink=glow segs=8 rings=5
 
// the hub face: a cap with a star burst
cyl cap on=wheel at=(0, 1.66, 0) h=.12 r=.95 round=.04 color=rimC segs=24
ball star x8 on=cap ring at=(.64, .12, 0) r=(.2, .07, .08) color=sunflower ink=glow segs=8 rings=4
ball boss on=cap at=(0, .1, 0) r=(.36, .22, .36) color=hubC segs=16 rings=8
 
// gondolas: a pin at the rim (pointing back) that counter-turns, a hanger and a bell-roofed car that stays level
cyl pin x12 on=wheel ring ring0=15 at=(R, 1.55, 0) rot=(180, -(15 + 360*i/n), 0) h=1.4 r=.07 color=sel(i - 6*floor(i/6), gA, gB, cherry, teal, sunflower, grape) segs=8 joint
rod hang on=pin at=(0, .7, 0) rot=(90, 0, 0) to=(0, -.75, 0) r=.05 sides=6 color=parent.color
lathe car on=pin at=(0, .7, -1.75) rot=(90, 0, 0) h=1.05 r=.62 depth=.75 prof=[0:.55 .12:.9 .5:1 .82:.98 1:.9] sq=3 bands=[.42:frameC .52:sel(parent.i - 6*floor(parent.i/6), gA, gB, cherry, teal, sunflower, grape)] color=sel(parent.i - 6*floor(parent.i/6), gA, gB, cherry, teal, sunflower, grape) segs=16 rings=6
cone roof on=pin at=(0, .7, -.9) rot=(90, 0, 0) h=.5 r=.72 r2=.08 depth=.8 stripes=[frameC sel(parent.i - 6*floor(parent.i/6), gA, gB, cherry, teal, sunflower, grape)] panels=8 scallop=.03 color=sel(parent.i - 6*floor(parent.i/6), gA, gB, cherry, teal, sunflower, grape) segs=16
ball knob on=roof at=(0, .52, 0) r=.09 color=hubC segs=8 rings=5
 
 
anim wheel ry spin hz=.035
// the pins point back along the axle, so the same spin turns them the other way: the cars stay level
anim pin ry spin hz=.035