按下按钮后，如何在破折号中更新 vtk 图像的显示？

问：

我是 plotly/dash 的全新手，我正在努力设计一个关于 3D 体积的主观实验。 基本上，我正在尝试加载一堆 3D 图像（来自预定义的播放列表），显示每个图像（一次一个），为显示的图像打分，然后切换到播放列表中的下一个。 我想出了以下代码，它显示了第一张图像，但不知何故，我找不到为下一个显示器更新图像的方法。

任何帮助将不胜感激。 谢谢。

from dash import Dash, dcc, html, Input, Output, State, callback
import dash_bootstrap_components as dbc
import dash
import dash_vtk
from dash_vtk.utils import to_volume_state
import itk
import sys
import webbrowser
import numpy as np


try:
    # VTK 9+
    from vtkmodules.vtkImagingCore import vtkRTAnalyticSource
except ImportError:
    # VTK =< 8
    from vtk.vtkImagingCore import vtkRTAnalyticSource



lines = []
# Read image playlist :
with open(r"playlist.txt", 'r') as fp:
    lines = fp.readlines()

NbImages = len(lines)

# Load vtk image (3D) :
volname = lines[0][:-1]

def loadVol(volname):
    itkImage = itk.imread(volname)
    vtkImage = itk.vtk_image_from_image(itkImage)
    vtkVol = to_volume_state(vtkImage)
    return(vtkVol)

vtkVol = loadVol(volname)

# Build the vtk View from the 3D image :
vtk_view = dash_vtk.View(
    id="vtk-view",
    background = [0.4,0.4,0.4],
    children=[
        dash_vtk.VolumeRepresentation([
        dash_vtk.VolumeController(),
        dash_vtk.Volume(state=vtkVol),
        dash_vtk.GeometryRepresentation()
        ]),
    ],
)



# Dash setup
app = Dash(__name__)

server = app.server


Scores = []

# Prepare the html page layout :
app.layout = html.Div([
    html.Div(style={"width": "100%", "height": "400px"},children=[vtk_view]),
    html.Div(dcc.Input(id='input-on-submit', type='text')),
    html.A(html.Button('NEXT', id='submit-val', n_clicks=0),href='/')
    ])
@app.callback(
    Output('vtk-view', 'children'),
    Input('submit-val', 'n_clicks'),
    State('input-on-submit', 'value'),
    prevent_initial_call=True
)
def update_output(n_clicks, value):
    Scores.append(value)

    volname = lines[len(Scores)-1][:-1]
    print("\nprocessing image : " + volname + "\tScore = " +str(value))

    vtkVol = loadVol(volname)

    vtk_view = dash_vtk.View(
        id="vtk-view",
        background = [0.4,0.4,0.4],
        children=[
            dash_vtk.VolumeRepresentation([
            dash_vtk.VolumeController(),
            dash_vtk.Volume(state=vtkVol),
            dash_vtk.GeometryRepresentation()
            ]),
        ],
    )

    if len(Scores) == NbImages:
        with open(r'output.txt', 'w') as fp:
            for item in Scores:
                fp.write("%s\n" % item)
        print('Done')
        sys.exit()

    return(vtk_view)


if __name__ == "__main__":
    app.run(debug=True)

我设法读取了播放列表，加载并显示了第一张图像，从该图像的观察者那里收集了分数，但我无法切换到播放列表中的下一张图像。