使用Three.js将修改后的平面几何导出为JSON

Question

我修改平面几何的顶点来创建新的几何学。但是当我导出几何学时，它仍然是一个平面几何，而我修改的顶点不包括在内。

如何将新的几何图形导出为JSON，包括所有更改？

这是我的密码：

var seg = 5;
var dim = 70;
var zScale = 20;
var geometry = new THREE.PlaneGeometry(dim,  dim, seg, seg );
var index = 0;

for (var gridY = 0; gridY < seg; gridY++) {
    for (var gridX = 0; gridX < seg; gridX++) {
        var z = Math.random() * zScale;
        geometry.vertices[index].z = z;
        index++;
    }
}

geometry.elementsNeedUpdate = true;
geometry.verticesNeedUpdate = true;
var expJson = geometry.toJSON();
console.log(expJson);

我导出的数据如下所示：

{
    height: 70
    heightSegments: 5
    metadata: {
        generator: "Geometry.toJSON"
        type: "PlaneGeometry"
    },
    version: 4.4
    type: "PlaneGeometry"
    uuid: "5F071B03-15EA-43CE-B4B3-4944E13D781C"
    width: 70
    widthSegments: 5
}

Answer 1

这是我使用的解决方案。如果有人有更好的，请把它寄出去。但这对我来说是可行的，而且相当整洁。

我只是添加了一个新的几何对象，并从平面几何复制眩晕和面孔。

var seg = 5;
var dim = 70;
var zScale = 20;
var geometry = new THREE.PlaneGeometry(dim,  dim, seg, seg );
var index = 0;

for (var gridY = 0; gridY < seg; gridY++) {
    for (var gridX = 0; gridX < seg; gridX++) {
        var z = Math.random() * zScale;
        geometry.vertices[index].z = z;
        index++;
    }
}

geometry.elementsNeedUpdate = true;
geometry.verticesNeedUpdate = true;

// The fix start ---
var neoGeo = new THREE.Geometry();
neoGeo.vertices = geometry.vertices;
neoGeo.faces = geometry.faces;
neoGeo.faceVertexUvs = geometry.faceVertexUvs;
// The fix end ---

var expJson = neoGeo.toJSON(); //Export json from the new geometry object
console.log(expJson);

Answer 2

如果需要原始数据，请参见https://github.com/mrdoob/three.js/issues/5483了解为什么需要转换为THREE.Geometry或THREE.BufferGeometry。

一个更简单的方法是(来自https://stackoverflow.com/a/26478256/128165)

var rawGeometry = new THREE.BufferGeometry().fromGeometry(geometry);
var expJson = rawGeometry.toJSON();

或

var rawGeometry = new THREE.Geometry();
rawGeometry.merge( geometry );
var expJson = rawGeometry.toJSON();