bydraw_geometrieswithdraw_geometries_with_custom_animationThe function can easily use the visualization of Open3D, everything can be done with the GUI. Press the H key in the visualization window to see related help information. more details:Visualize。
This tutorial focuses on the more advanced visualization function to customize the behavior of the visual window. Please refer to/Python/Advanced/customized_visualization.pyImplement the following routine.

Imitate the Draw_Geometries () function via Visualizer class

def custom_draw_geometry(pcd):
    # The following code implements the same effect as the following:
    # o3d.visualization.draw_geometries([pcd])
    vis = o3d.visualization.Visualizer()
    vis.create_window()
    vis.add_geometry(pcd)
    vis.run()
    vis.destroy_window()

This function is implementeddraw_geometriesThe same functionality is the same.

VisualizerClass has several variables, such asViewControlwithRenderOption. The following function reads the predefined in the JSON file stored in the JSON file.RenderOption。

def custom_draw_geometry_load_option(pcd):
    vis = o3d.visualization.Visualizer()
    vis.create_window()
    vis.add_geometry(pcd)
    vis.get_render_option().load_from_json("../../TestData/renderoption.json")
    vis.run()
    vis.destroy_window()

Change angle

To change the angle of view of the camera, you must first obtain an instance of the visual control. usechange_field_of_viewThe function changes the field of view.

def custom_draw_geometry_with_custom_fov(pcd, fov_step):
    vis = o3d.visualization.Visualizer()
    vis.create_window()
    vis.add_geometry(pcd)
    ctr = vis.get_view_control()
    print("Field of view (before changing) %.2f" % ctr.get_field_of_view())
    ctr.change_field_of_view(step=fov_step)
    print("Field of view (after changing) %.2f" % ctr.get_field_of_view())
    vis.run()
    vis.destroy_window()

The perspective can be set to [5,90]. Note functionchange_field_of_viewAdd a specified FOV to the current FOV. The default visualization has 60 ° FOV. Call the following code:

custom_draw_geometry_with_custom_fov(pcd, 90.0)

This will add 90 ° FOV on the default 60 °. When the maximum FOV is exceeded, the FOV will be set to 90 °.

The following code

custom_draw_geometry_with_custom_fov(pcd, -90.0)

The FOV will be set to 5 ° because 60 - 90 = -30 is below 5 °.

Use a callback function

def custom_draw_geometry_with_rotation(pcd):
    def rotate_view(vis):
        ctr = vis.get_view_control()
        ctr.rotate(10.0, 0.0)
        return False

    o3d.visualization.draw_geometries_with_animation_callback([pcd],
                                                              rotate_view)

functiondraw_geometries_with_animation_callbackPython's callback functionrotate_viewRegister as the idle function of the main loop. When the visual window is in idle state, he will rotate along the X axis. This defines animation behavior.

def custom_draw_geometry_with_key_callback(pcd):

    def change_background_to_black(vis):
        opt = vis.get_render_option()
        opt.background_color = np.asarray([0, 0, 0])
        return False

    def load_render_option(vis):
        vis.get_render_option().load_from_json(
            "../../TestData/renderoption.json")
        return False

    def capture_depth(vis):
        depth = vis.capture_depth_float_buffer()
        plt.imshow(np.asarray(depth))
        plt.show()
        return False

    def capture_image(vis):
        image = vis.capture_screen_float_buffer()
        plt.imshow(np.asarray(image))
        plt.show()
        return False

    key_to_callback = {}
    key_to_callback[ord("K")] = change_background_to_black
    key_to_callback[ord("R")] = load_render_option
    key_to_callback[ord(",")] = capture_depth
    key_to_callback[ord(".")] = capture_image
    o3d.visualization.draw_geometries_with_key_callbacks([pcd], key_to_callback)

The callback function can also be registered when the button event is generated. The above script registered four buttons. For example, pressing the K key will set the background to black.

Capture image with custom animation

def custom_draw_geometry_with_camera_trajectory(pcd):
    custom_draw_geometry_with_camera_trajectory.index = -1
    custom_draw_geometry_with_camera_trajectory.trajectory =\
            o3d.io.read_pinhole_camera_trajectory(
                    "../../TestData/camera_trajectory.json")
    custom_draw_geometry_with_camera_trajectory.vis = o3d.visualization.Visualizer(
    )
    if not os.path.exists("../../TestData/image/"):
        os.makedirs("../../TestData/image/")
    if not os.path.exists("../../TestData/depth/"):
        os.makedirs("../../TestData/depth/")

    def move_forward(vis):
        # This function is called within the o3d.visualization.Visualizer::run() loop
        # The run loop calls the function, then re-render
        # So the sequence in this function is to:
        # 1. Capture frame
        # 2. index++, check ending criteria
        # 3. Set camera
        # 4. (Re-render)
        ctr = vis.get_view_control()
        glb = custom_draw_geometry_with_camera_trajectory
        if glb.index >= 0:
            print("Capture image {:05d}".format(glb.index))
            depth = vis.capture_depth_float_buffer(False)
            image = vis.capture_screen_float_buffer(False)
            plt.imsave("../../TestData/depth/{:05d}.png".format(glb.index),\
                    np.asarray(depth), dpi = 1)
            plt.imsave("../../TestData/image/{:05d}.png".format(glb.index),\
                    np.asarray(image), dpi = 1)
            #vis.capture_depth_image("depth/{:05d}.png".format(glb.index), False)
            #vis.capture_screen_image("image/{:05d}.png".format(glb.index), False)
        glb.index = glb.index + 1
        if glb.index < len(glb.trajectory.parameters):
            ctr.convert_from_pinhole_camera_parameters(
                glb.trajectory.parameters[glb.index])
        else:
            custom_draw_geometry_with_camera_trajectory.vis.\
                    register_animation_callback(None)
        return False

    vis = custom_draw_geometry_with_camera_trajectory.vis
    vis.create_window()
    vis.add_geometry(pcd)
    vis.get_render_option().load_from_json("../../TestData/renderoption.json")
    vis.register_animation_callback(move_forward)
    vis.run()
    vis.destroy_window()

This function reads the camera track and then customizes the animation function.move_forwardTo traverse the camera trajectory. In this function, the color image and depth image are used separately.Visualizer.capture_depth_float_bufferwithVisualizer.capture_screen_float_bufferGo to capture and save it into a file.
Captured color image sequence

Captured depth image sequence