從面陣列中刪除重複的面 - Three.js

Question

我想從面陣列中刪除重複的面 - 我已經嘗試了下面的一些代碼，但我不知道如何完成它。

首先我很驚訝地發現：

new THREE.Vector3(0,0,0) == new THREE.Vector3(0,0,0) 

產生false（我希望它產生真正的），此外，下面還代碼產生false（我再次希望它產生真正的）。

var triangleGeometry = new THREE.Geometry(); 
    triangleGeometry.vertices.push(new THREE.Vector3(0.0, 1.0, 0.0)); 
    triangleGeometry.vertices.push(new THREE.Vector3(-1.0, -1.0, 0.0)); 
    triangleGeometry.vertices.push(new THREE.Vector3(1.0, -1.0, 0.0)); 
    triangleGeometry.faces.push(new THREE.Face3(0, 1, 2)); 

    var triangleGeometry2 = new THREE.Geometry(); 
    triangleGeometry2.vertices.push(new THREE.Vector3(0.0, 1.0, 0.0)); 
    triangleGeometry2.vertices.push(new THREE.Vector3(-1.0, -1.0, 0.0)); 
    triangleGeometry2.vertices.push(new THREE.Vector3(1.0, -1.0, 0.0)); 
    triangleGeometry2.faces.push(new THREE.Face3(0, 1, 2)); 

    triangleGeometry2.faces[0] === triangleGeometry.faces[0] - yields false 

至於我的代碼，以確定面部是否已經在對面的數組我寫了下面的：

  function faceInArray(arrayOfFaces,face) 
      { // https://stackoverflow.com/questions/29759480/how-to-customize-object-equality-for-javascript-set 
       // Determine whether a face is in an array of faces 
       // The ES6 Set object does not have any compare methods or custom compare extensibility. 
       // For this reason this function will be called before adding an face to an array of faces 
       // to ensure that duplicate faces are not placed in an array 

       for(let i = 0; i < arrayOfFaces.length; i++) 
       { 
        vertexaFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].a] 
        vertexbFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].b] 
        vertexcFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].c] 

        vertexaFace = buildingGeometry.vertices[face.a] 
        vertexbFace = buildingGeometry.vertices[face.b] 
        vertexcFace = buildingGeometry.vertices[face.c] 

        // Compare the vertices in each face I'm not sure how to do this? 


       } 
      } 

現在我不知道該如何從這裏PROCEDE簡單地檢查vertex1 == vertex2不起作用，因爲我在第一個代碼塊中介紹了它。在比較它們時，我是否真的需要提取每張臉的x，y和z座標？此外頂點的順序是否重要？

Answer 1

這是行不通的原因：new THREE.Vector3(0,0,0) == new THREE.Vector3(0,0,0) 是否==在這種情況下檢查兩個值是否是對同一對象的引用。但是你的向量是碰巧對x，y和z具有相同值的不同對象。你應該three.js所equals函數，而不是使用上的Vector3：

new THREE.Vector3(0,0,0).equals(new THREE.Vector3(0,0,0)) 

所以你的函數能像這樣工作：

function faceInArray(arrayOfFaces, face) { 
    for(let i = 0; i < arrayOfFaces.length; i++) { 
     vertexaFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].a] 
     vertexbFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].b] 
     vertexcFaceFromArray = buildingGeometry.vertices[arrayOfFaces[i].c] 

     vertexaFace = buildingGeometry.vertices[face.a] 
     vertexbFace = buildingGeometry.vertices[face.b] 
     vertexcFace = buildingGeometry.vertices[face.c] 

     if (vertexaFaceFromArray.equals(vertexaFace) && 
      vertexbFaceFromArray.equals(vertexbFace) && 
      vertexcFaceFromArray.equals(vertexcFace)) { 
      return true; 
     } 
    } 
    return false; 
} 

但是，當然，這只是檢查各面在完全相同的頂點訂單作爲輸入面。這取決於你打算如何使用它，但原則上面（1,2,3）與面（2,3,1）和（3,1,2）相同。另外，如果你的面是雙面的，那麼它也與頂點的任何次序相同。即（3,2,1），（2,1,3）和（1,3,2）。所以你可能想擴展代碼來檢查這些情況。