Motion Sample: load the full-res mesh directly, drop progressive LOD

The low-poly first paint was visibly under-tessellated for the first few seconds, which
looked worse than simply waiting. meshes_lo.pack is gone; meshes.pack (698k tris, 4.44 MB
gzip) loads with a byte-progress readout instead.

motionSample/index.html

@@ -122,10 +122,10 @@ const fail=m=>{const e=document.getElementById('err');e.style.display='grid';e.t
 (async function(){
 try{
   const scene_=await (await fetch('scene.json')).json();
-  // 网格是最大的一块。渐进加载: 先取 meshes_lo.pack(1.0MB) 出画面, 首帧之后再后台
-  // 取 meshes.pack(4.4MB) 热替换。二者都是 gzip 预压缩 —— HF static Space 不给二进制
-  // 自动 gzip。扩展名不用 .gz: 那样有些服务器会加 Content-Encoding: gzip, 浏览器已经
-  // 解过一遍, 这里再解就双重解压; 所以还按 gzip magic (1f 8b) 兜底判断。
+  // 网格是最大的一块(未压缩 12.6MB), gzip 预压缩后 4.4MB —— HF static Space 不给二进制
+  // 自动 gzip, 所以自己压。扩展名不用 .gz: 那样有些服务器会加 Content-Encoding: gzip,
+  // 浏览器已经解过一遍, 这里再解就双重解压; 所以还按 gzip magic (1f 8b) 兜底判断。
+  // 曾经做过"先低模再后台换高模"的渐进加载, 但开头那几秒面数明显不足很难看, 已去掉。
   async function getPack(url, onProgress){
     const r=await fetch(url);
     if(!r.ok) throw new Error(url+' '+r.status);
@@ -145,8 +145,8 @@ try{
     const w=ds.writable.getWriter(); w.write(buf); w.close();
     return new Response(ds.readable).arrayBuffer();
   }
-  const mbuf=await getPack('meshes_lo.pack',(g,t)=>
-    load(`Loading… ${(g/1048576).toFixed(1)}${t?' / '+(t/1048576).toFixed(1):''} MB`));
+  const mbuf=await getPack('meshes.pack',(g,t)=>
+    load(`Loading mesh… ${(g/1048576).toFixed(1)}${t?' / '+(t/1048576).toFixed(1):''} MB`));
   load('Building geometry…');
   const abuf=await (await fetch('motion.bin')).arrayBuffer();
   const Q=32767;
@@ -185,7 +185,7 @@ try{
     }
     return out;
   }
-  const meshGeo=buildGeo(mbuf, scene_.meshes_lo||scene_.meshes);
+  const meshGeo=buildGeo(mbuf, scene_.meshes);
   const meshGroup=new THREE.Group(); scene.add(meshGroup);
 
   const objs={}, jointNodes={}, axesList=[], axesByJoint={};
@@ -219,7 +219,6 @@ try{
         new THREE.MeshStandardMaterial({
           color:new THREE.Color(rgba[0],rgba[1],rgba[2]),
           metalness:.25,roughness:.6}));
-      me.userData.mesh=m.mesh;
       me.position.set(...m.xyz); me.rotation.set(m.rpy[0],m.rpy[1],m.rpy[2],'XYZ');
       if(m.scale)me.scale.set(...m.scale);
       o.add(me);
@@ -454,22 +453,6 @@ try{
   document.getElementById('load').remove();
   window.__ready=true;
 
-  // ── 渐进升级: 首屏用低模(1.0MB), 之后后台换全精度(4.4MB) ─────────────
-  // 实测把最终面数降到 320k/180k 躯干会出现裂面, 所以质量不能省, 只能把等待挪到后台。
-  if(scene_.meshes_lo) (async()=>{
-    const tip=document.getElementById('tip'), base=tip?tip.textContent:'';
-    try{
-      const buf=await getPack('meshes.pack',(g,t)=>{
-        if(tip&&t)tip.textContent=base+`  ·  full-res mesh ${Math.round(g/t*100)}%`;});
-      const hi=buildGeo(buf, scene_.meshes);
-      meshGroup.traverse(o=>{
-        const n=o.userData&&o.userData.mesh;
-        if(n&&hi[n]){const old=o.geometry; o.geometry=hi[n]; if(old&&old.dispose)old.dispose();}
-      });
-      window.__hires=true;
-    }catch(e){ console.warn('full-res mesh upgrade failed:',e); }
-    if(tip)tip.textContent=base;
-  })();
 }catch(e){fail('load failed: '+(e&&e.stack||e));}
 })();
 </script>

motionSample/meshes_lo.pack

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:861f4738f7ed599dc0876dc7cea5cf285e467b12dde077965c7ce24380570c72
-size 1038163