THREE JS computeVertexNormals（）性能

我有一個很大的緩衝區幾何圖形，大約有400萬個頂點，需要更新一個小區域的陰影。我目前隨機更新vertexNormals，但會導致延遲。我試圖使用幾何（How to quickly update a large BufferGeometry?）的updateRange.offset，但查看源代碼我不認爲這會影響vertexNormals（）函數。THREE JS computeVertexNormals（）性能

循環我1000次：

GRID.geometry.attributes.position.array[ (array_position + 2) ] = _position[2] - WEBGLzTranslate ; 
GRID.geometry.attributes.color.array[ (array_position) + 0 ] = color.r; 
GRID.geometry.attributes.color.array[ (array_position) + 1 ] = color.g; 
GRID.geometry.attributes.color.array[ (array_position) + 2 ] = color.b;

然後設置更新：

if(minArrayPosition < Infinity){ 
    GRID.geometry.attributes.position.updateRange = {}; 
    GRID.geometry.attributes.position.offset = minArrayPosition; 
    GRID.geometry.attributes.position.count = maxArrayPosition - minArrayPosition; 
    GRID.geometry.attributes.position.needsUpdate = true; 
    GRID.geometry.verticesNeedUpdate = true; 
} 

GRID.geometry.attributes.color.needsUpdate = true; 
GRID.material.needsUpdate = true; 
if(Math.random() > .99) 
{ 
    GRID.geometry.computeFaceNormals(); 
    GRID.geometry.computeVertexNormals(); 
    console.log('Updating Shadding'); 
}

理想我想有對vertexNormals範圍內的工作，我想。也許在這裏某處（BufferGeometry.js：657）：

if (attributes.position) { 

     var positions = attributes.position.array; 

     if (attributes.normal === undefined) { 

      this.addAttribute('normal', new BufferAttribute(new Float32Array(positions.length), 3)); 

     } else { 

      // reset existing normals to zero 

      var array = attributes.normal.array; 

      for (var i = 0, il = array.length; i < il; i ++) { 

       array[ i ] = 0; 

      } 

     } 

     var normals = attributes.normal.array; 

     var vA, vB, vC, 

     pA = new Vector3(), 
     pB = new Vector3(), 
     pC = new Vector3(), 

     cb = new Vector3(), 
     ab = new Vector3(); 

     // indexed elements 

     if (index) { 

      var indices = index.array; 

      if (groups.length === 0) { 

       this.addGroup(0, indices.length); 

      } 

      for (var j = 0, jl = groups.length; j < jl; ++ j) { 

       var group = groups[ j ]; 

       var start = group.start; 
       var count = group.count; 

       for (var i = start, il = start + count; i < il; i += 3) { 

        vA = indices[ i + 0 ] * 3; 
        vB = indices[ i + 1 ] * 3; 
        vC = indices[ i + 2 ] * 3; 

        pA.fromArray(positions, vA); 
        pB.fromArray(positions, vB); 
        pC.fromArray(positions, vC); 

        cb.subVectors(pC, pB); 
        ab.subVectors(pA, pB); 
        cb.cross(ab); 

        normals[ vA ] += cb.x; 
        normals[ vA + 1 ] += cb.y; 
        normals[ vA + 2 ] += cb.z; 

        normals[ vB ] += cb.x; 
        normals[ vB + 1 ] += cb.y; 
        normals[ vB + 2 ] += cb.z; 

        normals[ vC ] += cb.x; 
        normals[ vC + 1 ] += cb.y; 
        normals[ vC + 2 ] += cb.z; 

       } 

      }

我應該看看變形材料，而不是？謝謝

來源

2016-08-24 LrakWortep

聽起來像是你需要編寫自己的執行'computeVertexNormals（）'這不跟着你設置的限制。凍結是因爲在當前函數完成其處理或等待事件之前JavaScript不能執行任何其他操作。長的計算循環會在整個過程中「凍結」瀏覽器。 – Leeft

也許嘗試運行computeVertexNormals asynch在一個設置的時間間隔函數，運行一次後殺死自己？然後，我可以把它分開，但至少不會看到滯後？提交computeVertexNormals（{offset：Int，range：int}）作爲功能請求 – LrakWortep