Woodland spider

const meta={name:"Woodland spider"};

function shapeGeo(center,rings,n=7){
 const P=[],UV=[];const pts=rings.map((r,j)=>Array.from({length:n},(_,i)=>{const a=i*2*Math.PI/n;return [center[0]+(r[3]||0)+Math.cos(a)*r[1],center[1]+r[0],center[2]+Math.sin(a)*r[2]];}));
 function tri(a,b,c){P.push(...a,...b,...c);const normal=new THREE.Vector3(...b).sub(new THREE.Vector3(...a)).cross(new THREE.Vector3(...c).sub(new THREE.Vector3(...a)));const abs=[Math.abs(normal.x),Math.abs(normal.y),Math.abs(normal.z)],d=abs.indexOf(Math.max(...abs));for(const p of [a,b,c])UV.push(.5+p[(d+1)%3]-center[(d+1)%3],.5+p[(d+2)%3]-center[(d+2)%3]);}
 for(let j=0;j<rings.length-1;j++)for(let i=0;i<n;i++){const k=(i+1)%n;tri(pts[j][i],pts[j+1][i],pts[j+1][k]);tri(pts[j][i],pts[j+1][k],pts[j][k]);}
 const low=[center[0]+(rings[0][3]||0),center[1]+rings[0][0],center[2]],r=rings[rings.length-1],high=[center[0]+(r[3]||0),center[1]+r[0],center[2]];
 for(let i=0;i<n;i++){const k=(i+1)%n;tri(low,pts[0][i],pts[0][k]);tri(high,pts[pts.length-1][k],pts[pts.length-1][i]);}return meshGeo({positions:P,uvs:UV});
}
function skinChunk(name,geometry,material,region,bones,boneIndex,root){
 const g=remapUVToAtlas(geometry,material.map,region,{inputOrigin:'top-left',mode:'texel-center'}),indices=[],weights=[];
 for(let i=0;i<g.getAttribute('position').count;i++){indices.push(boneIndex,0,0,0);weights.push(1,0,0,0);}
 return createSkinnedPart(name,g,material,{parent:root,bones,indices,weights});
}
function limbGeo(a,b,r0,r1){const A=new THREE.Vector3(...a),B=new THREE.Vector3(...b),L=A.distanceTo(B),axis=B.clone().sub(A).normalize(),u=new THREE.Vector3(0,1,0).cross(axis).normalize(),v=axis.clone().cross(u).normalize(),P=[],UV=[],N=6;
 function at(t,ang,r){return A.clone().lerp(B,t).addScaledVector(u,Math.cos(ang)*r).addScaledVector(v,Math.sin(ang)*r);}
 function tri(p,q,r,uv){P.push(...p.toArray(),...q.toArray(),...r.toArray());UV.push(...uv);}
 for(let i=0;i<N;i++){const circumference=2*Math.PI*(r0+r1)/2,x=i/N*circumference,y=(i+1)/N*circumference,a=i*2*Math.PI/N,b=(i+1)*2*Math.PI/N,p=at(0,a,r0),q=at(0,b,r0),s=at(1,a,r1),t=at(1,b,r1);tri(p,q,t,[x,0,y,0,y,Math.min(L,.98)]);if(r1>0)tri(p,t,s,[x,0,y,Math.min(L,.98),x,Math.min(L,.98)]);tri(A,q,p,[.5,.5,.5+Math.cos(b)*r0,.5+Math.sin(b)*r0,.5+Math.cos(a)*r0,.5+Math.sin(a)*r0]);if(r1>0)tri(B,s,t,[.5,.5,.5+Math.cos(a)*r1,.5+Math.sin(a)*r1,.5+Math.cos(b)*r1,.5+Math.sin(b)*r1]);}return meshGeo({positions:P,uvs:UV});}
const legSpecs=[{"id": "L0", "hip": [0.26, 0.37, -0.17], "knee": [0.54, 0.57, -0.48], "foot": [0.69, 0, -0.84], "upperLength": 0.4631414470763764, "lowerLength": 0.6906518659932802, "bones": ["Spider_L0_Hip", "Spider_L0_Knee", "Spider_L0_Foot"], "contact": "Spider_L0_Contact", "restPlaneNormal": [-0.7835321761633123, 0.17107276705133856, -0.5973369545659992]}, {"id": "L1", "hip": [0.11, 0.37, -0.17], "knee": [0.24000000000000005, 0.57, -0.515], "foot": [0.31, 0, -0.88], "upperLength": 0.41943414262551393, "lowerLength": 0.6804594036384536, "bones": ["Spider_L1_Hip", "Spider_L1_Knee", "Spider_L1_Foot"], "contact": "Spider_L1_Contact", "restPlaneNormal": [-0.9473621687633991, 0.08185996118000088, -0.3095219991398312]}, {"id": "L2", "hip": [-0.1, 0.37, -0.17], "knee": [-0.11999999999999997, 0.57, -0.48], "foot": [-0.13000000000000003, 0, -0.84], "upperLength": 0.36945906403822326, "lowerLength": 0.6742403132415029, "bones": ["Spider_L2_Hip", "Spider_L2_Knee", "Spider_L2_Foot"], "contact": "Spider_L2_Contact", "restPlaneNormal": [-0.9984163436010449, -0.016459618048911346, 0.05379484923302773]}, {"id": "L3", "hip": [-0.27, 0.37, -0.17], "knee": [-0.43999999999999995, 0.57, -0.515], "foot": [-0.53, 0, -0.88], "upperLength": 0.43350317184537407, "lowerLength": 0.6828067076413353, "bones": ["Spider_L3_Hip", "Spider_L3_Knee", "Spider_L3_Foot"], "contact": "Spider_L3_Contact", "restPlaneNormal": [-0.9148611472882211, -0.10517595240472766, 0.38982957842913624]}, {"id": "R0", "hip": [0.26, 0.37, 0.17], "knee": [0.54, 0.57, 0.48], "foot": [0.69, 0, 0.84], "upperLength": 0.4631414470763764, "lowerLength": 0.6906518659932802, "bones": ["Spider_R0_Hip", "Spider_R0_Knee", "Spider_R0_Foot"], "contact": "Spider_R0_Contact", "restPlaneNormal": [0.7835321761633123, -0.17107276705133856, -0.5973369545659992]}, {"id": "R1", "hip": [0.11, 0.37, 0.17], "knee": [0.24000000000000005, 0.57, 0.515], "foot": [0.31, 0, 0.88], "upperLength": 0.41943414262551393, "lowerLength": 0.6804594036384536, "bones": ["Spider_R1_Hip", "Spider_R1_Knee", "Spider_R1_Foot"], "contact": "Spider_R1_Contact", "restPlaneNormal": [0.9473621687633991, -0.08185996118000088, -0.3095219991398312]}, {"id": "R2", "hip": [-0.1, 0.37, 0.17], "knee": [-0.11999999999999997, 0.57, 0.48], "foot": [-0.13000000000000003, 0, 0.84], "upperLength": 0.36945906403822326, "lowerLength": 0.6742403132415029, "bones": ["Spider_R2_Hip", "Spider_R2_Knee", "Spider_R2_Foot"], "contact": "Spider_R2_Contact", "restPlaneNormal": [0.9984163436010449, 0.016459618048911346, 0.05379484923302773]}, {"id": "R3", "hip": [-0.27, 0.37, 0.17], "knee": [-0.43999999999999995, 0.57, 0.515], "foot": [-0.53, 0, 0.88], "upperLength": 0.43350317184537407, "lowerLength": 0.6828067076413353, "bones": ["Spider_R3_Hip", "Spider_R3_Knee", "Spider_R3_Foot"], "contact": "Spider_R3_Contact", "restPlaneNormal": [0.9148611472882211, 0.10517595240472766, 0.38982957842913624]}];
async function build(){const root=createRoot('Spider');const material=await compilePortableMaterialSpecV3({"schemaVersion":3,"model":"pbrMetallicRoughness","name":"Forest spider-atlas","baseColor":16777215,"roughness":1,"metalness":0,"emissiveIntensity":1,"alphaMode":"opaque","alphaCutoff":0.5,"doubleSided":false,"textures":{"baseColor":{"kind":"resource","resourceId":"kiln.library.17bce067cd782389fdf4510d6d70cd0bedcd8b836bcae732c38c16f4cf6d4c92.base-color","sampler":{"minFilter":"nearest","magFilter":"nearest","wrapS":"clamp-to-edge","wrapT":"clamp-to-edge"}}}});const body=createBoneChain('SpiderBody',[{role:'body',offset:[0,.38,0]}],{parent:root});const all=[body.root],rigs=[];
 for(const l of legSpecs){const chain=createBoneChain('SpiderLeg_'+l.id,[{role:'leg.'+l.id.toLowerCase()+'.hip',offset:l.hip.map((v,i)=>v-[0,.38,0][i])},{role:'leg.'+l.id.toLowerCase()+'.knee',offset:l.knee.map((v,i)=>v-l.hip[i])},{role:'leg.'+l.id.toLowerCase()+'.foot',endEffector:true,contact:true,offset:l.foot.map((v,i)=>v-l.knee[i])}],{parent:body.root});all.push(...chain.nodes);rigs.push(chain);const a=createPivot(l.contact,[0,0,0],chain.end);a.name=l.contact;}
 body.root.name='Spider_Body';rigs.forEach((chain,j)=>chain.nodes.forEach((b,i)=>b.name=legSpecs[j].bones[i]));skinChunk('Abdomen',shapeGeo([-.24,.40,0],[[-.15,.20,.20],[0,.33,.27],[.18,.25,.22],[.23,.12,.14]],9),material,'body',all,0,root);skinChunk('Thorax',shapeGeo([.14,.36,0],[[-.13,.18,.16],[0,.24,.22],[.14,.19,.17]],8),material,'body',all,0,root);skinChunk('Head',shapeGeo([.34,.34,0],[[-.10,.13,.12],[.02,.17,.16],[.12,.11,.12]],7),material,'body',all,0,root);
 for(let i=0;i<legSpecs.length;i++){const l=legSpecs[i];skinChunk('Thigh_'+l.id,limbGeo(l.hip,l.knee,.052,.037),material,'legs',all,1+i*3,root);skinChunk('Shin_'+l.id,limbGeo(l.knee,l.foot,.037,0),material,'legs',all,2+i*3,root);}
 for(const z of [-.065,.065])skinChunk('Fang_'+(z<0?'L':'R'),limbGeo([.45,.30,z],[.52,.21,z*.7],.034,.007),material,'legs',all,0,root);
 const eye=gameMaterial(0x15211a,{roughness:.35});for(let i=0;i<4;i++)createPart('SpiderEye_'+i,shapeGeo([0,0,0],[[-.014,.013,.013],[.014,.016,.016]],5),eye,{position:[.474,.385+(i%2)*.038,-.066+i*.044],parent:root});
 return consolidateRenderParts(root);}
function animate(root){const tracks=[];for(let i=0;i<legSpecs.length;i++){const l=legSpecs[i],s=(i%2===0?1:-1),bendSign=l.id[0]==='L'?1:-1,lift=i%2===0?0:6,other=6-lift;tracks.push(rotationTrack(l.bones[0],[{time:0,rotation:[0,s*-10,0]},{time:.35,rotation:[0,s*10,0]},{time:.7,rotation:[0,s*-10,0]}]));tracks.push(rotationTrack(l.bones[1],[{time:0,rotation:[0,0,0]},{time:.175,rotation:[bendSign*(i%2===0?6:0),0,0]},{time:.35,rotation:[0,0,0]},{time:.525,rotation:[bendSign*(i%2===0?0:6),0,0]},{time:.7,rotation:[0,0,0]}]));}return [createClip('Scuttle',.7,tracks,{loop:true})];}
// Source-local consolidation only. It keeps the original procedural builders,
// triangle corners, material instances, rig and named rest frames editable.
function consolidateRenderParts(root){
 root.updateWorldMatrix(true,true);const rootInverse=root.matrixWorld.clone().invert(),groups=new Map(),parts=[];
 root.traverse(n=>{if(n.isMesh){if(Array.isArray(n.material))throw new Error('Consolidation requires one material per source part');parts.push(n);}});
 for(const n of parts){let g=groups.get(n.material);if(!g){g={material:n.material,parts:[],skin:!!n.isSkinnedMesh};groups.set(n.material,g);}if(g.skin!==!!n.isSkinnedMesh)throw new Error('Mixed skin/static material requires separate grouping');g.parts.push(n);}
 let groupIndex=0;
 for(const group of groups.values()){
  const positions=[],normals=[],uvs=[],indices=[],weights=[],ranges=[],first=group.parts[0],bones=group.skin?first.skeleton.bones:null;
  for(const n of group.parts){const geometry=n.geometry,p=geometry.getAttribute('position'),normal=geometry.getAttribute('normal'),uv=geometry.getAttribute('uv'),si=geometry.getAttribute('skinIndex'),sw=geometry.getAttribute('skinWeight'),matrix=rootInverse.clone().multiply(n.matrixWorld),normalMatrix=new THREE.Matrix3().getNormalMatrix(matrix),start=positions.length/9;
   if(group.skin&&(!n.bindMatrix.equals(first.bindMatrix)||n.skeleton.bones.length!==bones.length||n.skeleton.bones.some((b,i)=>b!==bones[i])||n.skeleton.boneInverses.some((m,i)=>!m.equals(first.skeleton.boneInverses[i]))))throw new Error('Source skin bind compatibility changed');
   for(let i=0;i<(geometry.index?.count??p.count);i++){const k=geometry.index?geometry.index.getX(i):i,P=new THREE.Vector3().fromBufferAttribute(p,k).applyMatrix4(matrix),N=new THREE.Vector3().fromBufferAttribute(normal,k).applyNormalMatrix(normalMatrix);positions.push(...P.toArray());normals.push(...N.toArray());uvs.push(uv.getX(k),uv.getY(k));if(group.skin){for(let j=0;j<4;j++){indices.push(si.getComponent(k,j));weights.push(sw.getComponent(k,j));}}}
   ranges.push({name:n.name,startTriangle:start,triangleCount:positions.length/9-start});
  }
  const geometry=new THREE.BufferGeometry();geometry.setAttribute('position',new THREE.Float32BufferAttribute(positions,3));geometry.setAttribute('normal',new THREE.Float32BufferAttribute(normals,3));geometry.setAttribute('uv',new THREE.Float32BufferAttribute(uvs,2));geometry.computeBoundingBox();geometry.computeBoundingSphere();
  // Combined body/leg atlas UVs are intentionally manual full-sheet coordinates.
  // No single named-region stamp is copied onto a mixed-region mesh. Exact source
  // mappings remain in the original builders and the editable triangle ranges.
  const name=group.skin?'SpiderSurface':group.material.alphaTest>0?'FoliageSurface':group.material.name==='Pine bark / broken plates'?'BarkSurface':group.material.name==='Cut endgrain'?'CutSurfaceCombined':'EyeSurface';
  const combined=group.skin?createSkinnedPart(name,geometry,group.material,{parent:root,bones,indices,weights}):createPart(name,geometry,group.material,{parent:root});combined.userData.consolidatedParts=ranges;if(group.material.alphaTest>0)markOpenShell(combined,'Original double-sided MASK foliage cards; intentional open sheets');
  for(const n of group.parts){const marker=new THREE.Object3D();marker.name=n.name;marker.position.copy(n.position);marker.quaternion.copy(n.quaternion);marker.scale.copy(n.scale);marker.userData.consolidatedTriangleRange=ranges.find(r=>r.name===n.name);const parent=n.parent;for(const child of [...n.children])marker.add(child);parent.add(marker);n.removeFromParent();}
  groupIndex++;
 }
 return root;
}