Unity+Vuforia+MediaPipe虚拟试穿：摄像头画面获取异常排查

我正在使用Unity搭配Vuforia AR SDK开发虚拟试穿应用。由于Vuforia不支持人体追踪，计划通过WebSocket建立Unity与Python的连接，将Unity端Vuforia的摄像头画面发送至Python，借助MediaPipe处理后返回关键关节坐标用于人体追踪。

目前已成功建立Unity与Python的WebSocket连接，可正常收发数据，但在尝试获取并发送Vuforia摄像头画面时遇到问题。参照Vuforia官方文档编写了名为CameraImageAccess的脚本（挂载到场景中的Vuforia ARCamera上），代码如下：

using UnityEngine;
using UnityEngine.UI;
using Vuforia;
using Image = Vuforia.Image;

public class CameraImageAccess : MonoBehaviour
{
    const PixelFormat PIXEL_FORMAT = PixelFormat.RGB888;
    const TextureFormat TEXTURE_FORMAT = TextureFormat.RGB24;

    public RawImage RawImage;

    Texture2D mTexture;
    bool mFormatRegistered;

    void Start()
    {
        // Register Vuforia Engine life-cycle callbacks:
        VuforiaApplication.Instance.OnVuforiaStarted += OnVuforiaStarted;
        VuforiaApplication.Instance.OnVuforiaStopped += OnVuforiaStopped;
        if (VuforiaBehaviour.Instance != null)
            VuforiaBehaviour.Instance.World.OnStateUpdated += OnVuforiaUpdated;
    }

    void OnDestroy()
    {
        // Unregister Vuforia Engine life-cycle callbacks:
        if (VuforiaBehaviour.Instance != null)
            VuforiaBehaviour.Instance.World.OnStateUpdated -= OnVuforiaUpdated;

        VuforiaApplication.Instance.OnVuforiaStarted -= OnVuforiaStarted;
        VuforiaApplication.Instance.OnVuforiaStopped -= OnVuforiaStopped;

        if (VuforiaApplication.Instance.IsRunning)
        {
            // If Vuforia Engine is still running, unregister the camera pixel format to avoid unnecessary overhead
            // Formats can only be registered and unregistered while Vuforia Engine is running
            UnregisterFormat();
        }

        if (mTexture != null)
            Destroy(mTexture);
    }

    /// 
    /// Called each time the Vuforia Engine is started
    /// 
    void OnVuforiaStarted()
    {
        mTexture = new Texture2D(0, 0, TEXTURE_FORMAT, false);
        // A format cannot be registered if Vuforia Engine is not running
        RegisterFormat();
    }

    /// 
    /// Called each time the Vuforia Engine is stopped
    /// 
    void OnVuforiaStopped()
    {
        // A format cannot be unregistered after OnVuforiaStopped
        UnregisterFormat();
        if (mTexture != null)
            Destroy(mTexture);
    }

    /// 
    /// Called each time the Vuforia Engine state is updated
    /// 
    void OnVuforiaUpdated()
    {
        var image = VuforiaBehaviour.Instance.CameraDevice.GetCameraImage(PIXEL_FORMAT);

        // There can be a delay of several frames until the camera image becomes available
        if (Image.IsNullOrEmpty(image))
            return;

        Debug.Log("\nImage Format: " + image.PixelFormat +
                  "\nImage Size: " + image.Width + " x " + image.Height +
                  "\nBuffer Size: " + image.BufferWidth + " x " + image.BufferHeight +
                  "\nImage Stride: " + image.Stride + "\n");

        // Override the current texture by copying into it the camera image flipped on the Y axis
        // The texture is resized to match the camera image size
        image.CopyToTexture(mTexture, true);

        RawImage.texture = mTexture;
        RawImage.material.mainTexture = mTexture;
    }

    /// 
    /// Register the camera pixel format
    /// 
    void RegisterFormat()
    {
        // Vuforia Engine has started, now register camera image format
        var success = VuforiaBehaviour.Instance.CameraDevice.SetFrameFormat(PIXEL_FORMAT, true);
        if (success)
        {
            Debug.Log("Successfully registered pixel format " + PIXEL_FORMAT);
            mFormatRegistered = true;
        }
        else
        {
            Debug.LogError("Failed to register pixel format " + PIXEL_FORMAT +
                           "\n the format may be unsupported by your device;" +
                           "\n consider using a different pixel format.");
            mFormatRegistered = false;
        }
    }

    /// 
    /// Unregister the camera pixel format
    /// 
    void UnregisterFormat()
    {
        Debug.Log("Unregistering camera pixel format " + PIXEL_FORMAT);
        VuforiaBehaviour.Instance.CameraDevice.SetFrameFormat(PIXEL_FORMAT, false);
        mFormatRegistered = false;
    }
}

运行Unity Play模式后，Vuforia初始化正常，脚本开始运行，但始终输出以下日志：

ConfigureVideoBackground
UnityEngine.Debug:Log (object)
Vuforia.Internal.Utility.UnityLogger:LogInfo (string)
Vuforia.Internal.Utility.Log:Info (string)
Vuforia.MonoCameraConfiguration:ConfigureVideoBackground (UnityEngine.Matrix4x4)
Vuforia.MonoCameraConfiguration:CheckForSurfaceChanges (UnityEngine.Matrix4x4)
Vuforia.CameraController:UpdateCamera (UnityEngine.Matrix4x4)
Vuforia.Internal.Core.StateProcessor:ProcessState (Vuforia.IVuState,System.Collections.Generic.IDictionary`2<int, Vuforia.Internal.Observers.IObserver>,Vuforia.Internal.Rendering.IVideoBackgroundRenderer,Vuforia.Internal.Rendering.IVBAugmentationRenderer,Vuforia.ICameraController,Vuforia.Internal.Core.IWorldOriginProvider,Vuforia.Internal.Observers.DeviceObserver)
Vuforia.Internal.Core.Engine:UpdateState ()
Vuforia.Internal.Core.Engine:OnUnityUpdate ()
System.Delegate:DynamicInvoke (object[])
Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeDelegate (System.Delegate,object[])
Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeWithExceptionHandling (System.Action)
Vuforia.Internal.Core.UnityLifeCycleListener:Update ()

虽然RegisterFormat()函数中显示"Successfully registered pixel format RGB888"，确认Vuforia支持该格式，但OnVuforiaUpdated()函数中本该输出的图像信息日志并未出现，说明Vuforia无法获取摄像头图像。我已尝试更新Vuforia SDK、新建3D/AR移动端项目，问题仍未解决，恳请提供排查或解决建议。

内容的提问来源于stack exchange，提问作者omyeh23145