How to Get RotationMatrix from Yaw, Feed and Roll

Question

Hi, I managed to find the yaw, feed and roll using the accelerator and magnetic sensor in my Android app. Now I want to rotate the Camera Target (min3d) object around a point in my scene according to the angles. As a result, you can watch the 3D scene by moving your Android device. I tried for several days to almost read all the related answers in SO, but I just can't work.

The movement that I get is completely insensitive. I confirmed that my jerk is between 0-360 and correct, the step is from -90 to 90 and is correct, and finally, the roll is between -180 and 180 and is consistent.

Basically, I do the matrix rotation and multiplication by my target object and up.

float[] rotation = new float[16]; Matrix.setIdentityM(rotation, 0); Matrix.rotateM(rotation, 0, (float) Math.toDegrees(roll), 0, 0, 1); Matrix.rotateM(rotation, 0, (float) Math.toDegrees(pitch)+90f, 1, 0, 0); Matrix.rotateM(rotation, 0, (float) Math.toDegrees(-azimut), 0, 1, 0); float[] target = new float[4]; float[] source = new float[]{0,0,150,0}; Matrix.multiplyMV(target, 0,rotation, 0, source, 0); float targetX = target[0] + 0; float targetY = target[1] + 150; float targetZ = -target[2] + 0; target = new float[4]; source = new float[]{0,1,0,0}; Matrix.multiplyMV(target, 0,rotation, 0, source, 0); float upX = target[0]; float upY = target[1]; float upZ = target[2]; scene.camera().target.x = targetX; scene.camera().target.y = targetY; scene.camera().target.z = targetZ; scene.camera().upAxis.x = upX; scene.camera().upAxis.y = upY; scene.camera().upAxis.z = upZ; 

Initially, my target is at (0,0150), and my vector is up (0,1,0).

Thanks for any help.

Answer 1

After the valine matrix, the target vector should be consistent, since the target is only a directional axis.

In fact, your goal is not vec3 (0,150,150), then the goal is vec3 (0,0,150). You rotate it and then add vec3 (0,150,0). So think about it, vec3 (0,0,150) is always vec3 (0,0,150) if you rotate the z axis.

Update

Yes, rotateM () multiplies the matrix you set and the matrix you set, so logically there are no problems.

  public static void rotateM(float[] rm, int rmOffset, float[] m, int mOffset, float a, float x, float y, float z) { synchronized(sTemp) { setRotateM(sTemp, 0, a, x, y, z); multiplyMM(rm, rmOffset, m, mOffset, sTemp, 0); } public static void setRotateM(float[] rm, int rmOffset, float a, float x, float y, float z) { rm[rmOffset + 3] = 0; rm[rmOffset + 7] = 0; rm[rmOffset + 11]= 0; rm[rmOffset + 12]= 0; rm[rmOffset + 13]= 0; rm[rmOffset + 14]= 0; rm[rmOffset + 15]= 1; a *= (float) (Math.PI / 180.0f); float s = (float) Math.sin(a); float c = (float) Math.cos(a); if (1.0f == x && 0.0f == y && 0.0f == z) { rm[rmOffset + 5] = c; rm[rmOffset + 10]= c; rm[rmOffset + 6] = s; rm[rmOffset + 9] = -s; rm[rmOffset + 1] = 0; rm[rmOffset + 2] = 0; rm[rmOffset + 4] = 0; rm[rmOffset + 8] = 0; rm[rmOffset + 0] = 1; } else if (0.0f == x && 1.0f == y && 0.0f == z) { rm[rmOffset + 0] = c; rm[rmOffset + 10]= c; rm[rmOffset + 8] = s; rm[rmOffset + 2] = -s; rm[rmOffset + 1] = 0; rm[rmOffset + 4] = 0; rm[rmOffset + 6] = 0; rm[rmOffset + 9] = 0; rm[rmOffset + 5] = 1; } else if (0.0f == x && 0.0f == y && 1.0f == z) { rm[rmOffset + 0] = c; rm[rmOffset + 5] = c; rm[rmOffset + 1] = s; rm[rmOffset + 4] = -s; rm[rmOffset + 2] = 0; rm[rmOffset + 6] = 0; rm[rmOffset + 8] = 0; rm[rmOffset + 9] = 0; rm[rmOffset + 10]= 1; } else { float len = length(x, y, z); if (1.0f != len) { float recipLen = 1.0f / len; x *= recipLen; y *= recipLen; z *= recipLen; } float nc = 1.0f - c; float xy = x * y; float yz = y * z; float zx = z * x; float xs = x * s; float ys = y * s; float zs = z * s; rm[rmOffset + 0] = x*x*nc + c; rm[rmOffset + 4] = xy*nc - zs; rm[rmOffset + 8] = zx*nc + ys; rm[rmOffset + 1] = xy*nc + zs; rm[rmOffset + 5] = y*y*nc + c; rm[rmOffset + 9] = yz*nc - xs; rm[rmOffset + 2] = zx*nc - ys; rm[rmOffset + 6] = yz*nc + xs; rm[rmOffset + 10] = z*z*nc + c; } } 

This android function rotateM () function is a combined version of these three matrices below

 void Matrix_Rotation_X(Matrix &out_M,const float angle) { float COS = (float)cos(angle); float SIN = (float)sin(angle); out_M.s[_0x0_]= 1.f; out_M.s[_0x1_]= 0.f; out_M.s[_0x2_]= 0.f; out_M.s[_0x3_]= 0.f; out_M.s[_1x0_]= 0.f; out_M.s[_1x1_]= COS; out_M.s[_1x2_]= SIN; out_M.s[_1x3_]= 0.f; out_M.s[_2x0_]= 0.f; out_M.s[_2x1_]=-SIN; out_M.s[_2x2_]= COS; out_M.s[_2x3_]= 0.f; out_M.s[_3x0_]= 0.f; out_M.s[_3x1_]= 0.f; out_M.s[_3x2_]= 0.f; out_M.s[_3x3_]= 1.f; } void Matrix_Rotation_Y(Matrix &out_M, const float angle) { float COS = (float)cos(angle); float SIN = (float)sin(angle); out_M.s[_0x0_]= COS; out_M.s[_0x1_]= 0.f; out_M.s[_0x2_]=-SIN; out_M.s[_0x3_]= 0.f; out_M.s[_1x0_]= 0.f; out_M.s[_1x1_]= 1.f; out_M.s[_1x2_]= 0.f; out_M.s[_1x3_]= 0.f; out_M.s[_2x0_]= SIN; out_M.s[_2x1_]= 0.f; out_M.s[_2x2_]= COS; out_M.s[_2x3_]= 0.f; out_M.s[_3x0_]= 0.f; out_M.s[_3x1_]= 0.f; out_M.s[_3x2_]= 0.f; out_M.s[_3x3_]= 1.f; } void Matrix_Rotation_Z( Matrix &out_M, const float angle) { float COS = (float)cos(angle); float SIN = (float)sin(angle); out_M.s[_0x0_]= COS; out_M.s[_0x1_]= SIN; out_M.s[_0x2_]= 0.f; out_M.s[_0x3_]= 0.f; out_M.s[_1x0_]= -SIN; out_M.s[_1x1_]= COS; out_M.s[_1x2_]= 0.f; out_M.s[_1x3_]= 0.f; out_M.s[_2x0_]= 0.f; out_M.s[_2x1_]= 0.f; out_M.s[_2x2_]= 1.f; out_M.s[_2x3_]= 0.f; out_M.s[_3x0_]= 0.f; out_M.s[_3x1_]= 0.f; out_M.s[_3x2_]= 0.f; out_M.s[_3x3_]= 1.f; } 

https://github.com/sunglab/StarEngine/blob/master/math/Matrix.cpp

Answer 2

You are mistaken in setting the target and upAxis values. you assign angle values ​​for goals and update upAxis with the same target values. However, the target is the x, y, z points in the 3D environment, and upAxis tells the camera to take this vector as a reference (changing upAxis calls the camera). Here is my implementation through accels and mags, motivated by ExampleAccelerometer.java

 public class ExampleAccelerometer extends RendererActivity implements SensorEventListener { private SkyBox mSkyBox; private final float[] mAccelerometerReading = new float[3]; private final float[] mMagnetometerReading = new float[3]; private final float[] mRotationMatrix = new float[16]; private final float[] mOrientation = new float[3]; private SensorManager mSensorManager; private Sensor mAccel, mMag; public Number3d upAxis; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE); mAccel = mSensorManager.getDefaultSensor( Sensor.TYPE_ACCELEROMETER); mMag = mSensorManager.getDefaultSensor( Sensor.TYPE_MAGNETIC_FIELD); Matrix.setIdentityM(mRotationMatrix, 0); } public void initScene() { scene.lights().add(new Light()); mSkyBox = new SkyBox(5.0f, 2); mSkyBox.addTexture(SkyBox.Face.North, R.drawable.wood_back, "north"); mSkyBox.addTexture(SkyBox.Face.East, R.drawable.wood_right, "east"); mSkyBox.addTexture(SkyBox.Face.South, R.drawable.wood_back, "south"); mSkyBox.addTexture(SkyBox.Face.West, R.drawable.wood_left, "west"); mSkyBox.addTexture(SkyBox.Face.Up, R.drawable.ceiling, "up"); mSkyBox.addTexture(SkyBox.Face.Down, R.drawable.floor, "down"); mSkyBox.scale().y = 0.8f; mSkyBox.scale().z = 2.0f; scene.addChild(mSkyBox); //Initial upAxis vector upAxis = new Number3d(-1,0,0); scene.camera().upAxis = upAxis; mSensorManager.registerListener(this, mAccel, SensorManager.SENSOR_DELAY_UI); mSensorManager.registerListener(this, mMag,SensorManager.SENSOR_DELAY_UI); } @Override protected void onDestroy() { super.onDestroy(); // Don't receive any more updates from either sensor. mSensorManager.unregisterListener(this); } @Override public void onAccuracyChanged(Sensor sensor, int accuracy) { // TODO Auto-generated method stub } @Override public void onSensorChanged(SensorEvent event) { if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) { System.arraycopy(event.values, 0, mAccelerometerReading, 0, mAccelerometerReading.length); } else if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) { System.arraycopy(event.values, 0, mMagnetometerReading, 0, mMagnetometerReading.length); } SensorManager.getRotationMatrix(mRotationMatrix, null, mAccelerometerReading, mMagnetometerReading); SensorManager.getOrientation(mRotationMatrix, mOrientation); //Camera Position scene.camera().position.x = 0; scene.camera().position.y = 0; scene.camera().position.z = 0; //Camera target position (where camera looks at ie position of interest) scene.camera().target.x = 0; scene.camera().target.y = 0; scene.camera().target.z = 50; //To multiply target with rotation create a temp vector with 4 parameter float[] p = new float[4]; p[0] = scene.camera().target.x; p[1] = scene.camera().target.y; p[2] = scene.camera().target.z; p[3] = 1; //Rotate target according to the rotation matrix derived via accel and mag sensor float[] target = new float[4]; Matrix.multiplyMV(target, 0, mRotationMatrix, 0, p, 0); // set rotated camera target (this creates 2d rotation with roll and pitch) scene.camera().target.x = target[0]; scene.camera().target.y = target[1]; scene.camera().target.z = target[2]; // change up axis for rolling with yaw parameter upAxis.x = (float)(Math.cos(mOrientation[0])); upAxis.y = (float) (Math.sin(mOrientation[0])); upAxis.z = 0; scene.camera().upAxis = upAxis; } }