threejs避免重复创建CSS2DObject

代码如下：

const css2DObjects = [];

const createLabelObj = (idText,) => {
    let div = document.getElementById(idText);

    for (var i = 0; i < css2DObjects.length; i++) {
        const preDiv = css2DObjects[i].element;
        if (preDiv.id === idText) {
            // 如果已存在，则先移除
            const divDom = css2Renderer.domElement;
            if (divDom && divDom.contains(preDiv)) {
                divDom.removeChild(preDiv)
            }
        }
    }

    // 给标签设置坐标位置
    let pointLabel = new CSS2DObject(div);
    css2DObjects.push({ element: div, object: pointLabel });
    return pointLabel;
}

export const addTags = (item) => {
    const item = model.getObjectByName(i.id)
    const tag = createLabelObj(i.id)
    item && item.add(tag)
}