stackwith.me — instancing reference excerpts
Source snapshot: 2026-10-28

These are excerpts from the local source used to prepare this edition.
They describe code, not a successful browser test or the state of a live service.
Line numbers refer to the original file. Full-file SHA-256 identifies that version.


File: src/assets/js/lab-ice.js
SHA-256: 4d27ceba0c7cd6ea78769efc97d65ff14838710ec3d04374f0ad7e39ff8b93f9
Lines 191–224

 191    own(chamberLight.shadow);
 192  
 193    const dummy=new THREE.Object3D();
 194    const batches=[];
 195    let iceTriangles=0;
 196    for(let variant=0;variant<variantCount;variant++) {
 197      const members=poses.filter(p=>p.family===variant);
 198      const geometry=sculpt(variant,divisions,variant<rows.length?rows[variant]:null,variant===vaultFamily),seeds=new Float32Array(members.length),energy=new Float32Array(members.length);
 199      const mesh=new THREE.InstancedMesh(geometry,material,members.length);
 200      mesh.name=`Sculpted frost course ${variant+1}`;
 201      mesh.castShadow=true;mesh.receiveShadow=true;mesh.frustumCulled=false;
 202      mesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
 203      members.forEach((p,i)=>{seeds[i]=p.seed;});
 204      geometry.setAttribute("aSeed",new THREE.InstancedBufferAttribute(seeds,1));
 205      geometry.setAttribute("aEnergy",new THREE.InstancedBufferAttribute(energy,1).setUsage(THREE.DynamicDrawUsage));
 206      iceTriangles+=geometry.index.count/3*members.length;
 207      group.add(mesh);batches.push({mesh,members,energy});
 208    }
 209  
 210    const debrisCount=phone?3:5;
 211    const debrisGeometry=sculpt(7,phone?8:14);
 212    const debris=new THREE.InstancedMesh(debrisGeometry,material,debrisCount);
 213    const debrisSeeds=new Float32Array(debrisCount);
 214    for(let i=0;i<debrisCount;i++) {
 215      const a=(i%2?1:-1)*(1.55+random()*.55),r=6.8+random()*4.3;
 216      const x=Math.sin(a)*r,z=Math.cos(a)*r;
 217      dummy.scale.set(.22+random()*.6,.14+random()*.24,.26+random()*.48);
 218      dummy.position.set(x,heightAt(x,z)+dummy.scale.y*.30,z);
 219      dummy.rotation.set(random()*.22,random()*6.28,random()*.16,"YXZ");
 220      dummy.updateMatrix();debris.setMatrixAt(i,dummy.matrix);debrisSeeds[i]=random();
 221    }
 222    debrisGeometry.setAttribute("aSeed",new THREE.InstancedBufferAttribute(debrisSeeds,1));
 223    debrisGeometry.setAttribute("aEnergy",new THREE.InstancedBufferAttribute(new Float32Array(debrisCount),1));
 224    debris.castShadow=true;debris.receiveShadow=true;debris.instanceMatrix.needsUpdate=true;


File: src/assets/js/lab-journey.js
SHA-256: 6c78ca4fb423ac4832c0f36ad1d00636f6ce836a3081db2a0ba600e6206068a5
Lines 186–233

 186    const particleMaterial = own(new THREE.ShaderMaterial({
 187      uniforms: particleU,
 188      vertexShader: `
 189        attribute float aSeed;attribute vec3 aOrigin,aSurfaceNormal;uniform float uTime,uCharge,uAssemble,uWave;
 190        varying vec3 vNormal,vMacroNormal,vView;varying float vLight;
 191        void main(){
 192          vec3 origin=aOrigin;float age=uTime-uWave;
 193          float wave=step(0.,age)*exp(-pow((length(origin)-age*7.)*1.3,2.))*exp(-age*1.2);
 194          vec3 drift=normalize(origin+vec3(.001))*(1.-uAssemble)*(1.2+aSeed*3.);
 195          drift+=normalize(origin+vec3(.001))*(uCharge*.11+wave*.65);
 196          drift+=sin(vec3(aSeed*47.,aSeed*71.,aSeed*29.)+uTime*.8)*(.007+uCharge*.016);
 197          vec4 p=instanceMatrix*vec4(position,1.);p.xyz+=drift;
 198          vNormal=normalize(mat3(modelMatrix)*mat3(instanceMatrix)*normal);
 199          vMacroNormal=normalize(mat3(modelMatrix)*aSurfaceNormal);
 200          vView=cameraPosition-(modelMatrix*p).xyz;
 201          vLight=aSeed*.09+uCharge*.20+wave*.65;
 202          gl_Position=projectionMatrix*modelViewMatrix*p;
 203        }`,
 204      fragmentShader: `
 205        varying vec3 vNormal,vMacroNormal,vView;varying float vLight;
 206        void main(){
 207          vec3 key=normalize(vec3(.54,.71,-.45));
 208          float mass=pow(max(dot(normalize(vMacroNormal),key),0.),.75);
 209          float facet=.74+.26*max(dot(normalize(vNormal),key),0.);
 210          float rim=pow(1.-max(dot(normalize(vMacroNormal),normalize(vView)),0.),3.);
 211          vec3 color=mix(vec3(.030,.043,.073),vec3(.36,.43,.53),mass)*facet;
 212          color+=vec3(.035,.055,.085)*rim+vec3(.24,.36,.50)*vLight;
 213          gl_FragColor=vec4(color,1.);
 214        }`,
 215    }));
 216    const grains = new THREE.InstancedMesh(particleGeometry, particleMaterial, particleCount);
 217    grains.name = "Source frost grains"; grains.frustumCulled = false;
 218    for (let i = 0; i < particleCount; i++) {
 219      sampler.sample(point, face);
 220      point.addScaledVector(face, (random() - .2) * .10);
 221      seeds[i] = random(); origins.set(point.toArray(), i * 3); surfaceNormals.set(face.toArray(), i * 3);
 222      dummy.position.copy(point);
 223      dummy.rotation.set(random() * 3, random() * 3, random() * 3);
 224      dummy.scale.setScalar(.65 + random() * .85); dummy.updateMatrix();
 225      grains.setMatrixAt(i, dummy.matrix);
 226    }
 227    particleGeometry.setAttribute("aSeed", new THREE.InstancedBufferAttribute(seeds, 1));
 228    particleGeometry.setAttribute("aOrigin", new THREE.InstancedBufferAttribute(origins, 3));
 229    particleGeometry.setAttribute("aSurfaceNormal", new THREE.InstancedBufferAttribute(surfaceNormals, 3));
 230    source.content.add(grains);
 231  
 232    const display = new THREE.Group();
 233    display.name = "Circular source display"; display.position.set(EXHIBIT_X[2], 6.80, 0);