Shotgun shell pair

const meta={name:'Caretaker equipment',description:'Original low-poly rural equipment; shared weathered wood and iron plus original shell, brass, rubber and honed-edge pixel regions.'};
const ITEM='shells',WOOD_SPEC={"schemaVersion":3,"model":"pbrMetallicRoughness","name":"Fresh split wood","baseColor":16777215,"roughness":1,"metalness":0,"emissiveIntensity":1,"alphaMode":"opaque","alphaCutoff":0.5,"doubleSided":false,"textures":{"baseColor":{"kind":"resource","resourceId":"kiln.library.dec8945f78a3dca6d5031b36094a0583f02b39b0e3978ed2c34418010f14fbd5.base-color","sampler":{"minFilter":"nearest-mipmap-linear","magFilter":"nearest","wrapS":"repeat","wrapT":"repeat"}}}},IRON_SPEC={"schemaVersion":3,"model":"pbrMetallicRoughness","name":"Worn iron","baseColor":16777215,"roughness":0.85,"metalness":0.25,"emissiveIntensity":1,"alphaMode":"opaque","alphaCutoff":0.5,"doubleSided":false,"textures":{"baseColor":{"kind":"resource","resourceId":"kiln.library.1870a95ffec8e00bc9daac56a32bc537547e002305e373c4ff7a97f098119fbe.base-color","sampler":{"minFilter":"nearest-mipmap-linear","magFilter":"nearest","wrapS":"repeat","wrapT":"repeat"}}}},DETAIL_SPEC={"schemaVersion":3,"model":"pbrMetallicRoughness","name":"Original tool edge, shell and brass detail pixels","roughness":0.7,"metalness":0,"emissiveIntensity":1,"alphaMode":"opaque","alphaCutoff":0.5,"doubleSided":false,"textures":{"baseColor":{"kind":"resource","resourceId":"kiln.library.3d181e24dfe2a2c6b475e9460dd1f32b0b31be32f0149f577ed4ad0679b8049f.base-color","sampler":{"minFilter":"nearest","magFilter":"nearest","wrapS":"clamp-to-edge","wrapT":"clamp-to-edge"}}}};
async function build(){
  const root=createRoot(ITEM==='axe'?'CaretakerAxe':ITEM==='shotgun'?'CaretakerShotgun':'TwoShellPickup');
  const wood=await compilePortableMaterialSpecV3(WOOD_SPEC),iron=await compilePortableMaterialSpecV3(IRON_SPEC),detail=await compilePortableMaterialSpecV3(DETAIL_SPEC),polished=detail.clone(),brass=detail.clone();polished.name='Honed steel edge';polished.metalness=.8;polished.roughness=.45;brass.name='Brass cartridge head';brass.metalness=.75;brass.roughness=.5;
  const anchors={};function anchor(name,position,parent=root){const node=new THREE.Object3D();node.name=name;node.position.fromArray(position);node.userData.nightmanAnchor={role:name,version:1,forward:'+X',up:'+Y'};parent.add(node);anchors[name]=node;return node;}
  function geom(p,uv,ix){let g=new THREE.BufferGeometry();g.setAttribute('position',new THREE.Float32BufferAttribute(p,3));g.setAttribute('uv',new THREE.Float32BufferAttribute(uv,2));g.setIndex(ix);g=g.toNonIndexed();g.computeVertexNormals();return g;}
  function loftX(stations,n=8){const p=[],uv=[],ix=[],stride=n+1;for(let j=0;j<stations.length;j++){const s=stations[j];for(let i=0;i<=n;i++){const a=i/n*Math.PI*2;p.push(s.x,s.y+s.ry*Math.cos(a),(s.z??0)+s.rz*Math.sin(a));uv.push(i/n,j/(stations.length-1));}}for(let j=0;j<stations.length-1;j++)for(let i=0;i<n;i++){const a=j*stride+i,b=a+stride;ix.push(a,a+1,b,a+1,b+1,b);}for(const [j,end]of[[0,false],[stations.length-1,true]]){const s=stations[j],c=p.length/3;p.push(s.x,s.y,s.z??0);uv.push(.5,.5);for(let i=0;i<n;i++){const a=j*stride+i;ix.push(c,end?a:a+1,end?a+1:a);}}return geom(p,uv,ix);}
  function loftY(stations,n=8){const p=[],uv=[],ix=[],stride=n+1;for(let j=0;j<stations.length;j++){const s=stations[j];for(let i=0;i<=n;i++){const a=i/n*Math.PI*2;p.push(s.x+s.rx*Math.cos(a),s.y,(s.z??0)+s.rz*Math.sin(a));uv.push(i/n,1-j/(stations.length-1));}}for(let j=0;j<stations.length-1;j++)for(let i=0;i<n;i++){const a=j*stride+i,b=a+stride;ix.push(a,b,a+1,a+1,b,b+1);}for(const [j,end]of[[0,false],[stations.length-1,true]]){const s=stations[j],c=p.length/3;p.push(s.x,s.y,s.z??0);uv.push(.5,.5);for(let i=0;i<n;i++){const a=j*stride+i;ix.push(c,end?a+1:a,end?a:a+1);}}return geom(p,uv,ix);}
  function mapWorld(g,axis='X',density=2){const p=g.getAttribute('position'),uv=g.getAttribute('uv');for(let i=0;i<p.count;i++)uv.setXY(i,p.getZ(i)*density+.5,(axis==='X'?p.getX(i):p.getY(i))*density+.5);return g;}
  function part(name,g,m,parent=root,position){return createPart(name,g,m,{parent,position:position??[0,0,0]});}
  function atlas(name,g,region,m=detail,parent=root,position){return part(name,remapUVToAtlas(g,detail.map,region,{inputOrigin:'top-left',mode:'texel-center'}),m,parent,position);}
  function polygonPlate(points,thickness){const p=[],uv=[],ix=[];for(const z of [-thickness/2,thickness/2])for(const [x,y]of points){p.push(x,y,z);uv.push((x+.08)/.26,(y-.40)/.14);}const n=points.length;for(let i=1;i<n-1;i++)ix.push(0,i+1,i,n,n+i,n+i+1);for(let i=0;i<n;i++){const next=(i+1)%n;ix.push(i,next,n+i,next,n+next,n+i);}for(let i=0;i<ix.length;i+=3){const swap=ix[i+1];ix[i+1]=ix[i+2];ix[i+2]=swap;}return geom(p,uv,ix);}
  function ringX(x0,x1,y,z,outer,inner,n=10){const p=[],uv=[],ix=[];for(const x of[x0,x1])for(const r of[outer,inner])for(let i=0;i<=n;i++){const a=i/n*Math.PI*2;p.push(x,y+r*Math.cos(a),z+r*Math.sin(a));uv.push(i/n,x===x0?0:1);}const stride=n+1;for(let i=0;i<n;i++){const a=i,b=i+2*stride,c=i+stride,d=i+3*stride;ix.push(a,a+1,b,a+1,b+1,b,c,d,c+1,c+1,d,d+1,a,c,a+1,a+1,c,c+1,b,b+1,d,b+1,d+1,d);}return geom(p,uv,ix);}
  function shell(name,parent,position=[0,0,0]){const group=new THREE.Object3D();group.name=name;group.position.fromArray(position);parent.add(group);atlas(name+'Hull',loftX([{x:.009,y:0,ry:.0118,rz:.0118},{x:.063,y:0,ry:.0118,rz:.0118}],10),'shell',detail,group);atlas(name+'Head',loftX([{x:0,y:0,ry:.0128,rz:.0128},{x:.009,y:0,ry:.0128,rz:.0128}],10),'brass',brass,group);atlas(name+'Primer',loftX([{x:-.0008,y:0,ry:.0038,rz:.0038},{x:0,y:0,ry:.0038,rz:.0038}],8),'brass',brass,group);anchor(name+'_base',[0,0,0],group);return group;}
  if(ITEM==='axe'){
    part('AshHaft',mapWorld(loftY([{x:-.008,y:-.13,rx:.024,rz:.019},{x:-.003,y:-.09,rx:.023,rz:.018},{x:.006,y:.10,rx:.020,rz:.016},{x:.012,y:.28,rx:.019,rz:.014},{x:0,y:.49,rx:.017,rz:.013}]),'Y'),wood);
    const outline=[[-.058,.432],[-.078,.463],[-.057,.515],[.06,.532],[.135,.515],[.166,.467],[.137,.421],[.05,.415]];part('ForgedAxeHead',mapWorld(polygonPlate(outline,.035),'Y'),iron);
    const bevel=geom([.137,.422,-.018,.167,.467,-.004,.135,.515,-.018,.137,.422,.018,.167,.467,.004,.135,.515,.018,.167,.467,-.004,.167,.467,.004,.135,.515,.018,.135,.515,-.018,.137,.422,-.018,.137,.422,.018],[0,1,1,.5,0,0,0,1,1,.5,0,0,1,.5,1,.5,0,0,0,0,0,1,0,1],[0,1,2,3,5,4,6,8,7,6,9,8,10,11,7,10,7,6]);atlas('HonedBlade',bevel,'edge',polished);
    part('HeadEyeCollar',mapWorld(loftY([{x:0,y:.41,rx:.025,rz:.024},{x:0,y:.436,rx:.025,rz:.024}]),'Y'),iron);anchor('grip_dominant',[0,0,0]);anchor('grip_support',[.01,.16,0]);anchor('blade_contact',[.164,.467,0]);anchor('haft_end',[-.008,-.13,0]);root.userData.nightman={version:1,item:ITEM,axis:'+X edge-facing, +Y shaft',intendedLength:.662,contacts:{blade_contact:'Cut-plane center, not a damage or collision solver'}};
  }else if(ITEM==='shotgun'){
    part('WalnutStock',mapWorld(loftX([{x:-.305,y:-.02,ry:.072,rz:.035},{x:-.23,y:-.005,ry:.060,rz:.031},{x:-.15,y:.018,ry:.036,rz:.025},{x:-.08,y:.044,ry:.029,rz:.022},{x:-.02,y:.05,ry:.04,rz:.031}],8),'X'),wood);
    atlas('ButtPad',loftX([{x:-.318,y:-.02,ry:.073,rz:.037},{x:-.305,y:-.02,ry:.073,rz:.037}],8),'rubber');part('Receiver',mapWorld(loftX([{x:-.025,y:.069,ry:.038,rz:.037},{x:.115,y:.073,ry:.035,rz:.037}],4),'X'),iron);
    // A true open trigger guard, not a solid slab across the finger space.
    const p=[],uv=[],ix=[],n=12;for(const z of[-.007,.007])for(const inner of[false,true])for(let i=0;i<n;i++){const a=i/n*Math.PI*2;p.push(.018+(inner?.027:.035)*Math.cos(a),.011+(inner?.025:.033)*Math.sin(a),z);uv.push(i/n,inner?1:0);}for(let i=0;i<n;i++){const a=i,b=(i+1)%n;ix.push(a,b,n+a,b,n+b,n+a,2*n+a,3*n+a,2*n+b,2*n+b,3*n+a,3*n+b,a,2*n+a,b,b,2*n+a,2*n+b,n+a,n+b,3*n+a,n+b,3*n+b,3*n+a);}part('TriggerGuard',mapWorld(geom(p,uv,ix),'X'),iron);part('Trigger',mapWorld(loftY([{x:.025,y:-.005,rx:.004,rz:.004},{x:.017,y:.027,rx:.004,rz:.004}],4),'Y'),iron);
    const breech=createPivot('Breech',[.095,.038,0],root);anchor('breech_hinge',[0,0,0],breech);
    for(const side of[-1,1]){const suffix=side<0?'left':'right';part('Barrel_'+suffix,mapWorld(ringX(.025,.595,.047,side*.016,.0145,.0095,10),'X'),iron,breech);anchor('chamber_'+suffix,[.025,.047,side*.016],breech);shell('LoadedShell_'+suffix,breech,[.027,.047,side*.016]);}
    part('ForeEnd',mapWorld(loftX([{x:.06,y:.010,ry:.025,rz:.040},{x:.17,y:.010,ry:.033,rz:.043},{x:.33,y:.014,ry:.028,rz:.040}],8),'X'),wood,breech);
    part('BarrelRib',mapWorld(loftX([{x:.028,y:.064,ry:.0025,rz:.007},{x:.585,y:.064,ry:.0025,rz:.007}],4),'X'),iron,breech);atlas('FrontSight',loftX([{x:.57,y:.07,ry:.004,rz:.003},{x:.58,y:.07,ry:.004,rz:.003}],4),'brass',brass,breech);
    anchor('grip_dominant',[0,0,0]);anchor('grip_support',[.28,.035,0]);anchor('muzzle',[.595,.047,0],breech);anchor('stock_contact',[-.31,-.02,0]);root.userData.nightman={version:1,item:ITEM,axes:'+X muzzle, +Y up',intendedLength:1.008,clipTargets:{breech:breech.name,leftShell:'LoadedShell_left',rightShell:'LoadedShell_right'},events:{Fire:[{phase:.05,event:'muzzle_flash'}],Reload:[{phase:.28,event:'extract_shells'},{phase:.68,event:'insert_shells'}]}};
  }else{for(const side of[-1,1]){const group=shell(side<0?'PickupShellLeft':'PickupShellRight',root,[side*.018,.0008,0]);group.rotation.z=Math.PI/2;}anchor('pickup_center',[0,.042,0]);root.userData.nightman={version:1,item:'two-shell-pickup',count:2,reuse:'Exact shotgun shell geometry and material family'};}
  return root;
}
function animate(root){if(ITEM!=='shotgun')return [];const targets=root.userData.nightman.clipTargets;
  return [createClip('Reload',2.4,[rotationTrack(targets.breech,[{time:0,rotation:[0,0,0]},{time:.55,rotation:[0,0,-32]},{time:1.85,rotation:[0,0,-32]},{time:2.4,rotation:[0,0,0]}],'EASE_IN_OUT'),positionTrack(targets.leftShell,[{time:0,position:[.027,.047,-.016]},{time:.8,position:[-.065,.047,-.016]},{time:1.15,position:[-.085,.047,-.016]},{time:1.65,position:[.027,.047,-.016]},{time:2.4,position:[.027,.047,-.016]}],'LINEAR'),positionTrack(targets.rightShell,[{time:0,position:[.027,.047,.016]},{time:.8,position:[-.065,.047,.016]},{time:1.15,position:[-.085,.047,.016]},{time:1.65,position:[.027,.047,.016]},{time:2.4,position:[.027,.047,.016]}],'LINEAR')],{loop:false})];
}