Rolling boulder

1asset rolling_boulder "Rolling boulder" complexity=3
2// the idol's curse: a two-metre ball of carved temple stone with a grinning face cut into it, its eye
3// pits and a ring of runes smouldering with trapped fire. Bones and a snapped spear from earlier thieves
4// are stuck in its crust, moss grows in the cracks. On roll it tumbles forward along +z, spitting gravel.
5let R = .95..1.05
6let stoneC = rockGrey:2|greystone|sandstone|rockCool
7let runeC = tomato:2|marigold|lime
8let mossC = moss:2|hedge
9 
10// the ball and its lumps
11ball core at=(0, R+.04, 0) r=R color=stoneC noise=.035 segs=24 rings=15 joint
12ball lump x7 on=core surf=(i*51+20, -50+i*17) lift=-.06 r=(.32, .2, .3) color=stoneC*.92 noise=.06 segs=8 rings=5
13puff moss x3 on=core surf=(i*120+70, 35-i*25) lift=-.05 r=.26 color=mossC segs=7 rings=5
14 
15// two smouldering rune bands either side of the face
16torus band x2 on=core at=(0, 0, 0) row=(1.04, 0, 0) rot=(0, 0, 90) R=R*.86 r=.05 color=runeC ink=glow segs=34 sides=6
17 
18// the grinning face on the front
19ball brow on=core at=(0, .4, .82)*R rot=(-25, 0, 0) r=(.48, .13, .18) color=stoneC*1.08 segs=14 rings=7
20ball eyePit on=core at=(.28, .2, .9)*R mirror r=(.17, .14, .12) color=inkDark segs=10 rings=6
21ball ember on=eyePit at=(0, 0, .1) r=(.08, .07, .05) color=runeC ink=glow segs=8 rings=5
22ball nose on=core at=(0, -.02, 1.0)*R r=(.12, .16, .1) color=stoneC*.95 segs=8 rings=6
23torus grin on=core at=(0, .05, .97)*R rot=(80, 0, 0) R=.34 r=.06 arc=150 color=inkDark segs=16 sides=5
24cone tooth x5 on=core at=(0, -.23, .96)*R row=(.12, 0, 0) rot=(160, 0, 0) h=.14 r=.05 color=cream segs=5
25 
26// trophies of earlier thieves: a snapped spear, a skull, a rib
27rod spear on=core at=(-.55, .55, -.55)*R to=(-.5, .7, -.45) r=.035 sides=6 color=walnut
28ball skull on=core surf=(250, 10) lift=-.05 r=(.17, .16, .17) color=cream segs=12 rings=8
29ball skullEye on=skull at=(.06, .02, .14) mirror r=(.04, .045, .03) color=inkDark segs=6 rings=4
30tube rib on=core at=(.85, -.2, -.45)*R pts=[0, 0, 0  .14, .2, .02  .1, .44, .04] r=.035 smooth sides=6 color=cream
31 
32// gravel spat out behind it
33ball pebble x3 at=(0, .07, -1.1) row=(.45, 0, -.12) r=(.1, .07, .09) color=stoneC*.9 noise=.1 segs=6 rings=4
34fx roll: puff on=pebble at=(0, .1, 0) n=4 spread=.3 hz=1.4
35 
36// at rest it creaks and shifts; on roll it tumbles forward
37anim core rx sin amp=2 hz=.25
38anim roll: core rx spin hz=.24
39