coordinate-transformation

I have written a small code to convert the device co-ordinates into world co-ordinates by multiplying the Rotation matrix(using getRotationMatrix) and the vector (Ax,Ay,Az) which are the accelerometer values. When I run this, and the phone is static, I get a very fluctuating value for the Z axis(from 9.3 to 10.3) and the other two are 0. However when I give the phone some acceleration in any direction , it still doesn't show any change to those values and they remain zero. This is the part of the code where I get the values. if(ctp.getType()==Sensor.TYPE_ACCELEROMETER){ Ca[0]=event.values[0];

i'm trying to run Madgwick's sensor fusion algorithm on iOS. Since the code is open source i already included it in my project and call the methods with the provided sensor values. But it seems, that the algorithm expects the sensor measurements in a different coordinate system. The Apple CoreMotion Sensor System is given on the right side, Madgewick's on the left. Here is the picture of the different coordinate systems . Both systems follow the right hand rule. For me it seems like there is a 90 degree rotation around the z axis. But this didn't work. I also tried to flip x and y (and invert

I am trying to position a div such that it is always at the highest point of an object offset left and up a little so it is not right on top of the vertex. You can see that here . Please see the working with no scene rotation snippet below if the jsfiddle link no longer works. I can tell you, it works fairly marvellously. However, for a project at work, I need to rotate the scene, itself. Apparently, this messes up the conversion to 2D screen coordinates. You can view this here . You can view the not working with scene rotation snippet below as well. As you can see, the label does not update