不能在 tree.enumNodeFragments() 委托中使用全局变量

Question

我试图通过 fragId 保存元素的旧材料，但无法执行此操作，因为 tree.enumNodeFragments() 文档或窗口内部不可访问。

    highlight(externalId, color, dict) {
    let viewer = this.viewer;
    var dbId = dict[externalId];


    let myMaterial = this.createMaterial(color);

    // used to rescale and remove the z-fighting
    let scaleRatio = 1.005; // this was determined as optimal through visual inspection

    var tree = NOP_VIEWER.model.getData().instanceTree;

    document.oldMaterials = {};


    tree.enumNodeFragments(dbId,
        function(fragId) {
         document.oldMaterials[fragId] = viewer.model.getFragmentList().getMaterial(fragId);

            viewer.model.getFragmentList().setMaterial(fragId, myMaterial);


            /* important technique if you want to remove z-fighting */
            let fragProxy = viewer.impl.getFragmentProxy(viewer.model, fragId);
            fragProxy.scale = new THREE.Vector3(scaleRatio, scaleRatio, scaleRatio);
            fragProxy.updateAnimTransform();
        },
        true);

    viewer.impl.invalidate(true);
}

Answer 1

document 和 window 都应该在回调函数的范围内可用，但这不是一个好习惯。尝试在highlight 函数的范围内定义旧材料的映射：

function highlight(externalId, color, dict) {
    const viewer = this.viewer;
    const dbId = dict[externalId];
    const myMaterial = this.createMaterial(color);
    // used to rescale and remove the z-fighting
    const scaleRatio = 1.005; // this was determined as optimal through visual inspection
    const tree = NOP_VIEWER.model.getData().instanceTree;
    const oldMaterials = {};

    tree.enumNodeFragments(dbId, function(fragId) {
        oldMaterials[fragId] = viewer.model.getFragmentList().getMaterial(fragId);
        viewer.model.getFragmentList().setMaterial(fragId, myMaterial);
        /* important technique if you want to remove z-fighting */
        const fragProxy = viewer.impl.getFragmentProxy(viewer.model, fragId);
        fragProxy.scale = new THREE.Vector3(scaleRatio, scaleRatio, scaleRatio);
        fragProxy.updateAnimTransform();
    },
    true);

    viewer.impl.invalidate(true);
}