Google最新VR（sdk的诞生）

Google最新VR消息

google最近退出了Day-dream的SDK测试版，提供给开发者，我把google的sdk运行了一遍并结合官网的介绍算搞明白了一些api的调用。下面时Google的demo地址Day-dreamDemo

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我们下载并且import到AS中

这里我们看到Google的demo中给了我们4个案例。供我们参考，其他的Libraries都是以arr的形式提供给我们。可以看出来Google的用心和信息。

需要注意的时：Google建议使用7.0系统 开启vr设置
当然我们依然可以使用低版本的系统（4.4以上为佳）

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我们依次看每一个demo

1. com.google.vr.samples.controllerclient
   手柄的控制demo
   
   
   我们清晰的看到OrientationView时自定义了一个GlsurfaceView的视图，ControllerClientActivity则时整个视图。

   • OrientationView的Code段

 public OrientationView(Context context, AttributeSet attributeSet) {    super(context, attributeSet);    setEGLContextClientVersion(2);    setEGLConfigChooser(8, 8, 8, 8, 16, 0);    setRenderer(new Renderer());    sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);    orientationSensor = sensorManager.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR);    phoneOrientationListener = new PhoneOrientationListener();  }

这里是自定义控件的初始化，初始了GL2.0 并且设置了旋转传感器的监听。

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private class Renderer implements GLSurfaceView.Renderer中最重要的对视图进行绘制矩阵

@Override    public final void onDrawFrame(GL10 unused) {      GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);      GLES20.glUseProgram(program);      // Set up camera.      Matrix.setIdentityM(tmpMatrix1, 0);      // Convert world space to head space.      Matrix.translateM(tmpMatrix1, 0, 0, 0, -VIEW_SIZE);      Matrix.multiplyMM(tmpMatrix2, 0, tmpMatrix1, 0, phoneInWorldSpaceMatrix, 0);      // Phone's Z faces up. We need it to face toward the user.      Matrix.rotateM(tmpMatrix2, 0, 90, 1, 0, 0);      if (startFromSensorTransformation != null) {        // Compensate for the yaw by rotating in the other direction.        Matrix.rotateM(tmpMatrix2, 0, -startFromSensorTransformation[0], 0, 1, 0);      } // Else we're in a transient state between a resetYaw call and an onSensorChanged call.      // Convert object space to world space.      if (controller != null) {        controller.update();        controller.orientation.toRotationMatrix(controllerInStartSpaceMatrix);      }      Matrix.multiplyMM(tmpMatrix1, 0, tmpMatrix2, 0, controllerInStartSpaceMatrix, 0);      // Set mvpMatrix.      int mvp = GLES20.glGetUniformLocation(program, "uMvpMatrix");      Matrix.multiplyMM(mvpMatrix, 0, projectionMatrix, 0, tmpMatrix1, 0);      GLES20.glUniformMatrix4fv(mvp, 1, false, mvpMatrix, 0);      // Draw.      int position = GLES20.glGetAttribLocation(program, "aPosition");      GLES20.glVertexAttribPointer(position, 3, GLES20.GL_FLOAT, false, 0, boxVertices);      GLES20.glEnableVertexAttribArray(position);      int color = GLES20.glGetAttribLocation(program, "aColor");      GLES20.glVertexAttribPointer(color, 4, GLES20.GL_FLOAT, false, 0, boxColors);      GLES20.glEnableVertexAttribArray(color);      GLES20.glDrawArrays(GLES20.GL_LINES, 0, vertexCount);      GLES20.glDisableVertexAttribArray(position);      GLES20.glDisableVertexAttribArray(color);    }  }

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2 . com.google.vr.sdk.samples.simplepanowidget
panorama(全景图片)沉溺demo

  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main_layout);    // Make the source link clickable.    TextView sourceText = (TextView) findViewById(R.id.source);    sourceText.setText(Html.fromHtml(getString(R.string.source)));    sourceText.setMovementMethod(LinkMovementMethod.getInstance());    panoWidgetView = (VrPanoramaView) findViewById(R.id.pano_view);    panoWidgetView.setEventListener(new ActivityEventListener());    // Initial launch of the app or an Activity recreation due to rotation.    handleIntent(getIntent());  }

以上我们可以看到初始话控件，以及设置一些事件的监听。（最重要的是学习到了新的知识（让Activity可以getIntent())

/**   * Called when the Activity is already running and it's given a new intent.   */  @Override  protected void onNewIntent(Intent intent) {    Log.i(TAG, this.hashCode() + ".onNewIntent()");    // Save the intent. This allows the getIntent() call in onCreate() to use this new Intent during    // future invocations.    setIntent(intent);    // Load the new image.    handleIntent(intent);  }

其中handleIntent的方法内写了一些引用图片的代码段（并不重要，不再展示）

再AsyTask中我看到了一个让我感觉很重要的东西

  panoOptions = new Options();          panoOptions.inputType = Options.TYPE_STEREO_OVER_UNDER;

Options 具有两个public常量

范围 名称 值 public TYPE_MONO（单独全景图片时使用） 1 public TYPE_STEREO_OVER_UNDER(全景图片拼接为上下两部分时候使用) 2 private TYPE_START_MARKER 0 private TYPE_END_MARKER 3

2中不同模式比较
* TYPE_MONO模式下
* TYPE_STEREO_OVER_UNDER模式下

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3 . com.google.vr.sdk.samples.simplevideowidget
最关注的莫过于 VR的音频播放了。在了解前，我们需要看一下Google告诉我们如何导入比如MP3,HlS等音频的操作。

/** * A test activity that renders a 360 video using {@link VrVideoView}. * It loads the video in the assets by default. User can use it to load any video files using the * command: *   adb shell am start -a android.intent.action.VIEW \ *     -n com.google.vr.sdk.samples.simplevideowidget/.SimpleVrVideoActivity \ *     -d /sdcard/FILENAME.MP4 * * To load HLS urls add "--ei inputFormat 2" to pass in an integer extra which will set * VrVideoView.Options.inputFormat. e.g. *   adb shell am start -a android.intent.action.VIEW \ *     -n com.google.vr.sdk.samples.simplevideowidget/.SimpleVrVideoActivity \ *     -d "https://EXAMPLE.COM/FILENAME.M3U8" \ *     --ei inputFormat 2 * * To specify that the video is of type stereo over under (has images for left and right eyes), * add "--ei inputType 2" to pass in an integer extra which will set VrVideoView.Options.inputType. * This can be combined with other extras. * e.g. *   adb shell am start -a android.intent.action.VIEW \ *     -n com.google.vr.sdk.samples.simplevideowidget/.SimpleVrVideoActivity \ *     -d "https://EXAMPLE.COM/FILENAME.MP4" \ *     --ei inputType 2 */

在我们导入前，我们需要了解视频的格式以及是否双眼等选择对应的类型，使用adb导入到手机的内存中。

 // Bind input and output objects for the view.        videoWidgetView = (VrVideoView) findViewById(R.id.video_view); //VR视频控件VrVideoView        videoWidgetView.setEventListener(new ActivityEventListener());  //设置视频的回掉（处理进度条等）

可以看到视频VR视频播放控件的初始化，和设置监听事件。

    Options options = new Options();                    options.inputType = Options.TYPE_STEREO_OVER_UNDER;

这里的模式和全景图片类似，不过注意多出来的几个Public属性，为音频的格式Default还是Hls.

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4 .com.google.vr.sdk.samples.treasurehunt

首先我们先看一下目录结构：
|-TreasureHuntActivity （主要的实现类）
|-WorldLayoutData （主要是需要渲染的视图矩阵坐标）

TreasureHuntActivity的code

我们需要初始化3D音效

    // Initialize 3D audio engine.    gvrAudioEngine = new GvrAudioEngine(this, GvrAudioEngine.RenderingMode.BINAURAL_HIGH_QUALITY);

画地板的Gl代码段

/**   * Draw the floor.   *   * <p>This feeds in data for the floor into the shader. Note that this doesn't feed in data about   * position of the light, so if we rewrite our code to draw the floor first, the lighting might   * look strange.   */  public void drawFloor() {    GLES20.glUseProgram(floorProgram);    // Set ModelView, MVP, position, normals, and color.    GLES20.glUniform3fv(floorLightPosParam, 1, lightPosInEyeSpace, 0);    GLES20.glUniformMatrix4fv(floorModelParam, 1, false, modelFloor, 0);    GLES20.glUniformMatrix4fv(floorModelViewParam, 1, false, modelView, 0);    GLES20.glUniformMatrix4fv(floorModelViewProjectionParam, 1, false, modelViewProjection, 0);    GLES20.glVertexAttribPointer(        floorPositionParam, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, 0, floorVertices);    GLES20.glVertexAttribPointer(floorNormalParam, 3, GLES20.GL_FLOAT, false, 0, floorNormals);    GLES20.glVertexAttribPointer(floorColorParam, 4, GLES20.GL_FLOAT, false, 0, floorColors);    GLES20.glEnableVertexAttribArray(floorPositionParam);    GLES20.glEnableVertexAttribArray(floorNormalParam);    GLES20.glEnableVertexAttribArray(floorColorParam);    GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 24);    checkGLError("drawing floor");  }

监测是否眼睛查看到视野中的物体代码(为了可以点击消除掉cube)

 /**   * Check if user is looking at object by calculating where the object is in eye-space.   *   * @return true if the user is looking at the object.   */  private boolean isLookingAtObject() {    // Convert object space to camera space. Use the headView from onNewFrame.    Matrix.multiplyMM(modelView, 0, headView, 0, modelCube, 0);    Matrix.multiplyMV(tempPosition, 0, modelView, 0, POS_MATRIX_MULTIPLY_VEC, 0);    float pitch = (float) Math.atan2(tempPosition[1], -tempPosition[2]);    float yaw = (float) Math.atan2(tempPosition[0], -tempPosition[2]);    return Math.abs(pitch) < PITCH_LIMIT && Math.abs(yaw) < YAW_LIMIT;  }

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