使用Open3d绘图在点云中添加文字标签

首先要确保Open3d升级到版本0.13.0以上。可以用以下代码查看一下Open3d的版本：

import open3d
open3d.__version__

如果版本较低，采用以下命令升级Open3d：

pip install --upgrade open3d

在windows上安装可能会遇到问题，建议以管理员身份进入cmd输入以下命令：

pip install --upgrade open3d -i http://mirrors.aliyun.com/pypi/simple/ --trusted-host mirrors.aliyun.com

Windows安装遇到问题参考：
1.https://blog.csdn.net/weixin_44098853/article/details/106496794
2.https://blog.csdn.net/weixin_43360896/article/details/114307061

显示文字标签的效果为：

直接上代码，代码含义很简单：

import numpy as np
import open3d as o3d
import open3d.visualization.gui as gui
import open3d.visualization.rendering as rendering


def make_point_cloud(npts, center, radius):
    pts = np.random.uniform(-radius, radius, size=[npts, 3]) + center
    cloud = o3d.geometry.PointCloud()
    cloud.points = o3d.utility.Vector3dVector(pts)
    colors = np.random.uniform(0.0, 1.0, size=[npts, 3])
    cloud.colors = o3d.utility.Vector3dVector(colors)
    return cloud


def high_level():
    app = gui.Application.instance
    app.initialize()

    points = make_point_cloud(100, (0, 0, 0), 1.0)

    vis = o3d.visualization.O3DVisualizer("Open3D - 3D Text", 1024, 768)
    vis.show_settings = True
    vis.add_geometry("Points", points)
    for idx in range(0, len(points.points)):
        vis.add_3d_label(points.points[idx], "{}".format(idx))

    vis.reset_camera_to_default()

    app.add_window(vis)
    app.run()


def low_level():
    app = gui.Application.instance
    app.initialize()

    points = make_point_cloud(100, (0, 0, 0), 1.0)

    w = app.create_window("Open3D - 3D Text", 1024, 768)
    widget3d = gui.SceneWidget()
    widget3d.scene = rendering.Open3DScene(w.renderer)
    mat = rendering.Material()
    mat.shader = "defaultUnlit"
    mat.point_size = 5 * w.scaling
    widget3d.scene.add_geometry("Points", points, mat)
    for idx in range(0, len(points.points)):
        widget3d.add_3d_label(points.points[idx], "{}".format(idx))
    bbox = widget3d.scene.bounding_box
    widget3d.setup_camera(60.0, bbox, bbox.get_center())
    w.add_child(widget3d)

    app.run()

if __name__ == "__main__":
    high_level()
    #low_level()

参考资料：
1.https://github.com/isl-org/Open3D/issues/3894
2.https://github.com/isl-org/Open3D/blob/master/examples/python/gui/text3d.py