WebCAD/sample/CalUV.ts

function updateUV(geometry)
{

    // 据我所知，没有自动计算UV的方法。

    // 你必须计算自己。计算一个平面的紫外线是相当容易的，这个网站解释如何：计算纹理坐标

    // 对于一个复杂的形状，我不知道如何。也许你可以检测平面。

    // 编辑

    // 这是一个平面表面的示例代码，(x, y, z)其中z = 0：

    geometry.computeBoundingBox();

    var max = geometry.boundingBox.max,
        min = geometry.boundingBox.min;
    var offset = new THREE.Vector2(0 - min.x, 0 - min.y);
    var range = new THREE.Vector2(max.x - min.x, max.y - min.y);
    var faces = geometry.faces;

    if (!geometry.faceVertexUvs)
    {
        geometry.faceVertexUvs = [[]];
    }
    geometry.faceVertexUvs[0] = [];

    for (var i = 0; i < faces.length; i++)
    {

        var v1 = geometry.vertices[faces[i].a],
            v2 = geometry.vertices[faces[i].b],
            v3 = geometry.vertices[faces[i].c];

        geometry.faceVertexUvs[0].push([
            new THREE.Vector2((v1.x + offset.x) / range.x, (v1.y + offset.y) / range.y),
            new THREE.Vector2((v2.x + offset.x) / range.x, (v2.y + offset.y) / range.y),
            new THREE.Vector2((v3.x + offset.x) / range.x, (v3.y + offset.y) / range.y)
        ]);
    }
    geometry.uvsNeedUpdate = true;
}