Xamarin.Android 与基于 Android 设备方向的 UrhoSharp 相机节点旋转

Question

在我的 Xamarin.Android 应用程序中，我有从设备的 地磁旋转矢量 获得的 X、Y、Z 轴方向数据复合传感器并使用 CameraNode 的 SensorManager.GetOrientation( ) method. I want to apply this orientation data in UrhoSharp's scene on the Rotation 属性进行处理。换句话说，我想使用设备 "orientation" 传感器来控制场景的相机。

到目前为止我在 SensorChanged 事件处理程序中做了什么：

// app -> an instance of Urho.SimpleApplication
public void OnSensorChanged(SensorEvent e) {
    if (e.Sensor.Type == SensorType.GeomagneticRotationVector) {
        var rm = new float[9];
        SensorManager.GetRotationMatrixFromVector(rm, e.Values.ToArray());
        var ov = new float[3];
        SensorManager.GetOrientation(rm, ov);
        app.Pitch = (Urho.MathHelper.RadiansToDegrees(ov[0]) + 360) % 360;      // map [-Pi...+Pi] to [0...360]
        app.Yaw = (Urho.MathHelper.RadiansToDegrees(ov[1]) + 360) % 360;        // map [-Pi/2...+Pi/2] to [0...360]
        app.CameraNode.Rotation = new Urho.Quaternion(app.Pitch, app.Yaw, 0);
    }
}

但不幸的是，它并没有像预期的那样工作，而且相机总是看向错误的方向。有什么想法吗？

Answer 1

OnSensorChanged应该是这样的：

   if (e.Sensor == mRotationSensor)
    {
        var rm = new float[9];
        SensorManager.GetRotationMatrixFromVector(rm, e.Values.ToArray());
        var ov = new float[3];
        SensorManager.GetOrientation(rm, ov);
        app.pitch = (Urho.MathHelper.RadiansToDegrees(ov[1]) + 360) % 360;      // map [-Pi...+Pi] to [0...360]
        app.yaw = (Urho.MathHelper.RadiansToDegrees(ov[0]) + 360) % 360;
        Log.Error("pitch=",app.pitch+"");
        Log.Error("yaw=", app.yaw + "");
        // map [-Pi/2...+Pi/2] to [0...360]
        app.cameraNode.Rotation = new Urho.Quaternion(app.pitch, app.yaw, 0);

    }

并且您需要在 OnCreate 方法中为您的 SensorManager 添加这些：

 mSensorManager = (SensorManager)GetSystemService(Activity.SensorService);
 mRotationSensor = mSensorManager.GetDefaultSensor(SensorType.RotationVector);
 mSensorManager.RegisterListener(this, mRotationSensor, SensorDelay.Game);

并添加变量：

 private SensorManager mSensorManager;
 private Sensor mRotationSensor;

最后别忘了为您实现 ISensorEventListener 接口 Activity。

我在 github

上提供了一个演示

Answer 2

最后我在@joe

的一些研究和帮助下解决了这个问题

这是方法的最终版本：

// [app] is an instance of Urho.SimpleApplication
public void OnSensorChanged(SensorEvent e) {
    if (e.Sensor.Type == SensorType.GeomagneticRotationVector) {
        var inR = new float[9];
        SensorManager.GetRotationMatrixFromVector(inR, e.Values.ToArray());
        var outR = new float[9];
        // we need to remap cooridante system, since the Y and Z axes will be swapped, when we pick up the device 
        if (SensorManager.RemapCoordinateSystem(inR, Android.Hardware.Axis.X, Android.Hardware.Axis.Z, outR)) {
            var ov = new float[3];
            SensorManager.GetOrientation(outR, ov);
            try {
                app.Pitch = (MathHelper.RadiansToDegrees(ov[1]) + 360) % 360;
                app.Yaw = (MathHelper.RadiansToDegrees(ov[0]) + 360) % 360;
                app.CameraNode.Rotation = new Quaternion(app.Pitch, app.Yaw, 0);
            }
            catch (System.Exception ex) {
                // while Urho.SimpleApplication is not fully started, the [app] properties are not available
                System.Diagnostics.Trace.WriteLine(ex.Message);
            }
        }
    }
}

Answer 3

另一种可能的使用四元数的解决方案：

public void OnSensorChanged(SensorEvent e) {
    if (e.Sensor.Type == SensorType.GeomagneticRotationVector) {
        var qv = new float[4];
        SensorManager.GetQuaternionFromVector(qv, e.Values.ToArray());
        try {
            app.CameraNode.Rotation = new Quaternion(qv[1], -qv[3], qv[2], qv[0]);
            app.CameraNode.Pitch(90.0f);
            app.CameraNode.Roll(180.0f);
        }
        catch (System.Exception ex) {
        }
    }
}

Xamarin.Android 与基于 Android 设备方向的 UrhoSharp 相机节点旋转

Xamarin.Android vs. UrhoSharp camera node rotation based on Android device orientation

android

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urhosharp