Question

我正在尝试使用three.js手动构建一个立方体，通过声明它的向量和面;我可以使用下面的代码来完成它，但是，材料似乎没有按预期工作，而是立方体呈现为纯黑色。

var geom = new THREE.Geometry(); 
var v1 = new THREE.Vector3( -1,  1, 0.1 ),
    v2 = new THREE.Vector3(  1,  1, 0.1 ),
    v3 = new THREE.Vector3(  1, -1, 0.1 ),
    v4 = new THREE.Vector3( -1, -1, 0.1 ),
    v5 = new THREE.Vector3( -1,  1, 2   ),
    v6 = new THREE.Vector3(  1,  1, 2   ),
    v7 = new THREE.Vector3(  1, -1, 2   ),
    v8 = new THREE.Vector3( -1, -1, 2   );

geom.vertices.push(v1,v2,v3,v4,v5,v6,v7,v8);

geom.faces.push(
  new THREE.Face3(0,1,3),
  new THREE.Face3(1,2,3),
  new THREE.Face3(4,5,7),
  new THREE.Face3(5,6,7),
  new THREE.Face3(1,4,5),
  new THREE.Face3(0,1,4),
  new THREE.Face3(2,3,7),
  new THREE.Face3(2,6,7),
  new THREE.Face3(0,3,7),
  new THREE.Face3(0,4,7),
  new THREE.Face3(1,2,5),
  new THREE.Face3(2,5,6)  
);

var mat = new THREE.MeshNormalMaterial();
mat.side = THREE.DoubleSide;
var cube = new THREE.Mesh( geom, mat);
scene.add(cube);

如果我正常渲染立方体，使用下面的代码，立方体会按预期渲染。

cube = new THREE.Mesh(new THREE.CubeGeometry(2, 2, 2), new THREE.MeshNormalMaterial());
scene.add(cube);

Answer 1

您尚未指定顶点法线。对于快速的东西，计算面法线，如下：

geom.computeFaceNormals();

但您应该学习如何在自定义几何体中设置顶点法线。

另外，面对“缠绕顺序”应该是逆时针方向。你不是一直这样做的。

如果您正确定义了面孔，则可以删除side = THREE.DoubleSide。

three.js r.90

MeshNormalMaterial不处理three.js自定义几何体：几何体呈现为黑色

1 个答案: