function run(inputs, controls) { const trace = inputs?.capture ? [] : null; const path = []; const feet = [[-3,-3,0],[3,-3,0],[3,3,0],[-3,3,0]]; const clamp = (n, low, high) => Math.max(low, Math.min(high, n)); const mix = (a, b, t) => a + (b - a) * t; const add = (a, b) => a.map((v, i) => v + b[i]); const scale = (a, n) => a.map(v => v * n); const sub = (a, b) => add(a, scale(b, -1)); const dot = (a, b) => a.reduce((sum, v, i) => sum + v * b[i], 0); const length = v => Math.hypot(...v); const unit = a => scale(a, 1 / Math.max(1e-8,length(a))); const cross = ([a,b,c], [x,y,z]) => [b*z-c*y, c*x-a*z, a*y-b*x]; const lerp = (a,b,t) => add(a,scale(sub(b,a),t)); const smooth = t => { const p=clamp(t,0,1); return p*p*(3-2*p); }; const clip = ([x,y,z])=>[clamp(x,-3,3),clamp(y,-3,3),clamp(z,.14,4.8)]; // Keep the site and the four contacts fixed. Each rule supplies its own route. function append(route) { path.push(...route.slice(path.length ? 1 : 0)); } function round(route, amount, steps) { const points=[route[0]]; for(let i=1;i>> 0; return () => { state = (Math.imul(state, 1664525) + 1013904223) >>> 0; return state / 4294967296; }; } function checkedSeed(seed) { if (!Number.isInteger(seed) || seed < 1 || seed > 9999) throw new Error('Choose a seed from 1 to 9999.'); return randomFrom(seed); } const { seed } = controls; const random = checkedSeed(seed); const width=17, levels=13, step=.375; const id=(x,y,z)=>(x*width+y)*levels+z; const xyz=i=>[Math.floor(i/(width*levels)),Math.floor(i/levels)%width,i%levels]; const world=i=>xyz(i).map((n,k)=>n*step-(k<2?3:0)); const anchors=feet.map(([x,y])=>id(x<0?0:width-1,y<0?0:width-1,0)); const count=width*width*levels; const adjacent=Array.from({length:count},()=>[]); const unitSteps=[[1,0,0],[-1,0,0],[0,1,0],[0,-1,0],[0,0,1],[0,0,-1]]; for(let i=0;i=0 && x=0 && y0 && z{ const [x,y]=xyz(foot); const ports=[[x+(x===0?1:-1),y,n-1],[x,y+(y===0?1:-1),n]]; for(const [u,v,span] of ports){ const near=id(u,v,1); adjacent[foot].push(near); adjacent[near].push(foot); for(let z=1;zi%levels<=levels-3+span && (!reserved.has(i)||reserved.get(i)===span); const phase=Array.from({length:6},()=>2*Math.PI*random()); const field=Array.from({length:count},(_,i)=>{ const [x,y,z]=xyz(i); return Math.sin(.47*x+.24*y+.54*z+phase[0]) + .72*Math.sin(-.28*x+.61*y-.31*z+phase[1]) + .46*Math.cos(.37*x-.34*y+.44*z+phase[2]); }); const born=new Uint8Array(count); const distance=new Int16Array(count), queue=new Uint16Array(count); function reachable(goal,span){ distance.fill(-1); let size=1; queue[0]=goal; distance[goal]=0; for(let k=0;k=0 || born[j] || j%levels===0 || !available(j,span)) continue; distance[j]=distance[i]+1; queue[size++]=j; } } } for(let span=0;span<3;span++){ const start=anchors[span], goal=anchors[span+1], budget=86; const route=[world(start)], steps=[]; let tip=start, previous=-1; born[start]=1; for(let tick=0;tip!==goal;tick++){ reachable(goal,span); const rest=budget-tick; const p=xyz(tip), last=previous<0?[0,0,1]:sub(p,xyz(previous)); const [x,y,z]=p; const drift=[ Math.sin(.44*y+.22*z+phase[3]), Math.sin(.41*z-.28*x+phase[4]), Math.cos(.38*x+.33*y+phase[5]) ]; const options=[]; for(const next of adjacent[tip]){ if(born[next] || distance[next]<0 || distance[next]>=rest) continue; const q=xyz(next), heading=sub(q,p); const crowd=adjacent[next].reduce((sum,j)=>sum+Number(j!==tip && born[j]),0); const returnBias=.035+1.3*smooth((tick/budget-.58)/.42); const score=1.12*dot(heading,drift)+.60*dot(heading,last)+.97*field[next] + .16*q[2] + .32*random()-1.05*crowd-returnBias*distance[next] - (next===goal && tickb.score-a.score); if(!options.length) throw new Error(`No remaining connected route at span ${span+1}, tick ${tick}.`); previous=tip; tip=options[0].next; born[tip]=1; const q=world(tip); if(trace) steps.push({from:route.at(-1),chosen:q,candidates:options.map(({next})=>world(next)),index:tick+1}); route.push(q); } if(trace) trace.push({route,steps}); append(round(route,.36,2)); } // Give overlapping passes room for the tube, leaving the four contacts fixed. // The simulation decides the route. This step only moves near neighbours. const gap = 0.185; const fixed = path.map(p => p[2] === 0); const stations = [0]; for (let i=1; igap || Math.min(c[k],d[k])-Math.max(a[k],b[k])>gap) return false; } const u=sub(b,a), v=sub(d,c), r=sub(a,c); const uu=dot(u,u), vv=dot(v,v), uv=dot(u,v); const ru=dot(r,u), rv=dot(r,v), den=uu*vv-uv*uv; let s=den>1e-10 ? clamp((uv*rv-vv*ru)/den,0,1) : 0; let t=(uv*s+rv)/vv; if(t<0 || t>1){ t=clamp(t,0,1); s=clamp((uv*t-ru)/uu,0,1); } const delta=sub(add(r,scale(u,s)),scale(v,t)); const distance=Math.hypot(...delta); if(distance>=gap) return false; const direction=distance>1e-7 ? scale(delta,1/distance) : [1,0,0]; const weights=[1-s,s,t-1,-t].map((weight,k)=>fixed[[i,i+1,j,j+1][k]] ? 0 : weight); const total=dot(weights,weights); if(total<1e-8) return false; const shift=scale(direction,0.72*(gap-distance)/total); [i,i+1,j,j+1].forEach((k,n)=>{ if(fixed[k]) return; const [x,y,z]=add(path[k],scale(shift,weights[n])); path[k]=clip([x,y,z]); }); return true; } for(let iteration=0;iteration<32;iteration++){ let moved=false; for(let i=0;i.30 && separate(i,j)) moved=true; } } if(!moved) break; } const curve = path; // Sweep one circular section in a parallel-transport frame. const radius = 0.050; const sides = 10; const vertices = []; const faces = [Array.from({length:sides},(_,j)=>sides-1-j)]; let normal=[0,1,0]; for(let i=0;iNumber(v.toFixed(5)))); if(i){ const a=(i-1)*sides+j, b=(i-1)*sides+(j+1)%sides; faces.push([a,b,b+sides,a+sides]); } } } const last=vertices.length-sides; faces.push(Array.from({length:sides},(_,j)=>last+j)); return { version:2, units:'metres', objects:[{type:'MESH',name:'One continuous tube',color:'#3954b5',vertices,faces}] }; }