用于 OpenGL 的 Android 传感器 [英] Android Sensors for OpenGL

问题描述

我想让 android 传感器与 opengl 一起使用，以将 opengl 的摄像头旋转到手机指向的任何位置.

I want to get the android sensors to work with opengl to rotate the opengl's camera to wherever the phone is pointing to.

详细说明:如果玩家在看东方，我想在游戏中opengl的相机也指向东方；如果玩家指向天空，我想将opengl的相机指向天空等等.

To elaborate: if the player is looking at east, I'd like to the opengl's camera points east too on the game; if the player points to the sky, I'd like to point the opengl's camera to the sky and so on.

我尝试使用 getRotationMatrix 并在 opengl 上加载矩阵，但它只适用于上下方向，如果我将单元格转到两侧，则没有区别.这是我到目前为止所做的(应用程序处于横向模式):

I've tried using getRotationMatrix and load the matrix on the opengl but it only works on the up-down direction, if I turn the cell to the sides, there is no difference. Here is what I've done so far (the app is in landscape mode):

    public void onSensorChanged(SensorEvent evt) {
    int type=evt.sensor.getType();
    float alpha = 0.8f;

    //Smoothing the sensor data a bit
    if (type == Sensor.TYPE_MAGNETIC_FIELD) {
      geomag[0]=geomag[0]*alpha+evt.values[0]*(1-alpha);
      geomag[1]=geomag[1]*alpha+evt.values[1]*(1-alpha);
      geomag[2]=geomag[2]*alpha+evt.values[2]*(1-alpha);
    } else if (type == Sensor.TYPE_ACCELEROMETER) {
      gravity[0]= gravity[0]*alpha+evt.values[0]*(1-alpha);
      gravity[1]= gravity[1]*alpha+evt.values[1]*(1-alpha);
      gravity[2]= gravity[2]*alpha+evt.values[2]*(1-alpha);
    }

    if ((type==Sensor.TYPE_MAGNETIC_FIELD) || (type==Sensor.TYPE_ACCELEROMETER)) {
      rotationMatrix = new float[16];
      SensorManager.getRotationMatrix(rotationMatrix, null, gravity, geomag);
      SensorManager.remapCoordinateSystem( 
        rotationMatrix, 
        SensorManager.AXIS_Y, 
        SensorManager.AXIS_MINUS_X, 
        rotationMatrix );
     if (AOGLRenderer.rotationmatrix==null) AOGLRenderer.rotationmatrix = new float[16];
     AOGLRenderer.rotationmatrix = rotationMatrix;
    }       
  }

在opengl代码中:

and in the opengl code:

        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | // OpenGL docs.
                       GL10.GL_DEPTH_BUFFER_BIT);
    gl.glLoadIdentity();
    if (rotationmatrix!=null) gl.glLoadMatrixf(rotationmatrix, 0);
    gl.glPushMatrix();
    gl.glTranslatef(0, 0, -70);
    g.draw(gl);
    gl.glPopMatrix();
    alpha+=2f;
    gl.glTranslatef(0, -15, 0);
    c.draw(gl);

我希望真正做到这一点的人可以分享他们的代码！我真的很感激！谢谢大家！

I'd like that someone who actually did it could share their code! I'd really appreciate it! Thank you all!

推荐答案

这是我做同样事情的方式(我的应用程序也是横向的).首先我得到方向值(类似于你做的方式):

Here is the way I did the same thing (my App was also in landscape). First I get the orientation values (similar to the way you do):

final float pi = (float) Math.PI;
final float rad2deg = 180/pi;
public static float x; //pitch
public static float y; //roll
public static float z; //azimuth    
float[] gravity = new float[3];
float[] geomag = new float[3];
float[] inOrientMatrix = new float[16];
float[] outOrientMatrix= new float[16];
float orientation[] = new float[3]; 
public static GLSurfaceView glView;

//  (...)

public void onSensorChanged(SensorEvent event) {
switch (event.sensor.getType()){  
        case Sensor.TYPE_ACCELEROMETER:  gravity = event.values.clone();
        break;
        case Sensor.TYPE_MAGNETIC_FIELD: geomag = event.values.clone();
        break;
        }
if (gravity != null && geomag != null){
if (SensorManager.getRotationMatrix(inOrientMatrix, null, gravity, geomag)){
        SensorManager.remapCoordinateSystem(inOrientMatrix, SensorManager.AXIS_X, SensorManager.AXIS_Z, outOrientMatrix);
        SensorManager.getOrientation(outOrientMatrix, orientation);
        x = orientation[1]*rad2deg; //pitch
        y = orientation[0]*rad2deg; //azimuth
        z = orientation[2]*rad2deg; //roll
        glView.requestRender();
｝

然后在我的渲染中，在 onDrawFrame(GL10 gl) 我做:

Then in my rendered, in the onDrawFrame(GL10 gl) I do:

 gl.glLoadIdentity();
 GLU.gluLookAt(gl, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);      
 gl.glRotatef(MainActivity.x, 1.0f, 0.0f, 0.0f);
 gl.glRotatef(MainActivity.y, 0.0f, 1.0f, 0.0f);
 gl.glRotatef(MainActivity.z, 0.0f, 0.0f, 1.0f);
 //in case you have transformation, eg. the position of the object, you can do them here 
 //gl.Translatef(0.0f, 0.0f, -DISTANCE NORTH); 
 //gl.Translatef(0.0f, DISTANCE EAST, 0.0f); 
 gl.glPushMatrix();
 //object draw

换句话说，我围绕着我旋转整个世界.更好的方法是使用 glLookAt 更改相机的方向，眼睛位于 (0,0,0) 和 (0,1,0) 是向上向量，但我根本无法获得我的 center_view x,y,z 值正确.

In other words, I rotate the whole world around me. A better way would be to change the direction of the camera using glLookAt, with the eye positioned at (0,0,0) and (0,1,0) being the up vector, but I simply couldn't get my center_view x,y,z values correctly.

希望这会有所帮助...

Hope this helps...

这篇关于用于 OpenGL 的 Android 传感器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！