使用CardBoard和Rajawali VR Android中的觸摸事件來移動相機

Question

目前，我正在開發適用於Android的VR應用程序，該應用程序使用Google CardBoard和Rajawali播放360視頻。 傳感器工作正常，但是我無法使用觸摸來正確拖動場景或相機。 有什么方法可以在此應用程序中啟用觸摸模式嗎？

任何幫助是極大的贊賞！ 謝謝。

Answer 1

我從事過同一件事，這就是我所使用的：

首先，看一下Rajawali的ArcballCamera類。 您可以在此處看到如何處理觸摸事件以通過觸摸事件旋轉攝像機。

問題是，當用戶在屏幕上移動時，我不喜歡旋轉的默認行為，因此我根據前一個獨立完成了另一種實現，並直接旋轉了我想要的球體而不是相機，這樣就可以了（所有這些都在我的Renderer類中，順便說一句）：

首先，聲明：

private GestureDetector detector;           //gesture detector
private ScaleGestureDetector scaleDetector; //scale detector (for zooming)
private GestureListener gListener;          //gesture listener
private ScaleListener sListener;            //scale listener
private View.OnTouchListener touchListener; //touch events listener
private boolean isRotating;                 //true if the sphere is rotating
private boolean isScaling;                  //true if the sphere is scaling
private float xInicial,yInicial;            //inicial touch point
//sphere's yaw and pitch, used for rotation
private double yaw,pitch, yawAcumulado=0, pitchAcumulado=0, yawAcumuladoR=0, pitchAcumuladoR=0;
//physical to logical (in 3D world) conversion: screen scroll to sphere rotation
private final double gradosPorBarridoX=120, gradosPorBarridoY=90;
private final double gradosPorPixelYaw, gradosPorPixelPitch;

在渲染器的構造函數中，我開始了inizalization（定時器和控件用於視頻控件視圖，因此請不要注意這些）：

    DisplayMetrics outMetrics = new DisplayMetrics();
    ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(outMetrics);
    gradosPorPixelPitch = gradosPorBarridoY / outMetrics.heightPixels;
    gradosPorPixelYaw = gradosPorBarridoX / outMetrics.widthPixels;
    addListeners();
    ...
    //from Rajawali ArcballCamera class
private void addListeners(){
    ((Activity)context).runOnUiThread(new Runnable() {
        @Override
        public void run() {
            gListener = new GestureListener();
            sListener = new ScaleListener();
            detector = new GestureDetector(context, gListener);
            scaleDetector = new ScaleGestureDetector(context, sListener);
            touchListener = new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    scaleDetector.onTouchEvent(event); //see if it is a scale event
                    //if not, check whether it is a scroll
                    if (!isScaling) {
                        detector.onTouchEvent(event);
                        //or an up motion
                        if (event.getAction() == MotionEvent.ACTION_UP) {
                            if (!isRotating) {
                                //change video control view's visibility
                                TouchActivity.timer.cancel();
                                if (TouchActivity.control.getVisibility() == View.INVISIBLE) {
                                    TouchActivity.control.setVisibility(View.VISIBLE);
                                    TouchActivity.timer.start(); //timer is restarted
                                } else {
                                    TouchActivity.control.setVisibility(View.INVISIBLE);
                                }
                            } else {
                                isRotating = false;   //cancel rotation
                            }
                        }
                    }
                    return true;
                }
            };
            TouchActivity.principal.setOnTouchListener(touchListener);
        }
    });
}

最后但並非最不重要的一點是，事件偵聽（用於縮放和旋轉）：

/**
 * called when the rotation starts
 * @param x
 * @param y
 */
private void startRotation(float x, float y){
    xInicial = x;
    yInicial = y;
}

/**
 * called during the consecutive events of a rotation movement
 * @param x
 * @param y
 */
private void updateRotation(float x, float y){
    float difX = xInicial - x;
    float difY = yInicial - y;
    yaw= difX * gradosPorPixelYaw;
    pitch = difY * gradosPorPixelPitch;
    yawAcumulado+=yaw;
    pitchAcumulado+=pitch;
}

/**
 * event listener. if the user scrolls his finger through the screen, it sends the
 * touch event to calculate the sphere's rotation
 */
private class GestureListener extends GestureDetector.SimpleOnGestureListener{
    @Override
    public boolean onScroll(MotionEvent event1, MotionEvent event2, float distanceX, float distanceY) {
        //starts or updates the rotation with the upcoming event x and y screen values
        if(!isRotating) {
            startRotation(event2.getX(), event2.getY());
            isRotating=true;
            return false;
        }else{
            isRotating = true;
            updateRotation(event2.getX(), event2.getY());
            return false;
        }
    }
}

/**
 * event listener. Zooms in or out depending on the user's action
 */
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener{
    //zooms in or out according to the scale detector value
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        if(detector.getScaleFactor()>1){
            if(earthSphere.getScaleX()*1.1<120){
                earthSphere.setScaleX(earthSphere.getScaleX()*1.1);
                earthSphere.setScaleY(earthSphere.getScaleY() * 1.1);
                earthSphere.setScaleZ(earthSphere.getScaleZ() * 1.1);
            }
        }else{
            if(earthSphere.getScaleX()*0.9>0.95) {
                earthSphere.setScaleX(earthSphere.getScaleX() * 0.9);
                earthSphere.setScaleY(earthSphere.getScaleY() * 0.9);
                earthSphere.setScaleZ(earthSphere.getScaleZ() * 0.9);
            }
        }
        return true;
    }

    //the zoom begins
    @Override
    public boolean onScaleBegin (ScaleGestureDetector detector) {
        isScaling = true;
        isRotating = false;
        return super.onScaleBegin(detector);
    }

    //the zoom ends
    @Override
    public void onScaleEnd (ScaleGestureDetector detector) {
        isRotating = false;
        isScaling = false;
    }
}

解決了所有這些問題后，只需在每個渲染器上設置方向，如下所示：

    yawAcumuladoR = (yawAcumulado) * 0.04;
    pitchAcumuladoR = (pitchAcumulado) * 0.04;
    Quaternion q = new Quaternion();
    q.fromEuler(yawAcumuladoR, pitchAcumuladoR, 0);
    earthSphere.setOrientation(q);

正如我所說的，這對我有用，但是我只是在旋轉球體。 將其添加到您的需求中應該並不難，除了您擁有Arcball類的相機外，它可能更適合您的需求。 無論如何，我希望這對您有用。