Dfyjkt

I'm working on OpenGL ES 2.0 on an Android augmented reality app. My goal is to display a virtual object (for now, a rectangle) at a given position to give the impression that it has a real location in the world. So far, Im able to display a blue rectangle where I want (for example, at point (0;0.5;-1) in meters).

When I rotate the head, the rectangle goes in the opposite direction, which is the expected behaviour. However, it is not "fast enough" : I can still see half of it when I should not be able to see it at all because I'm facing another direction.

My first thought was that the issue was related to a too big FOV when I create the projection Matrix. As shown below, I'm using perspective projection :

@Override
public void onSurfaceChanged(GL10 unused, int width, int height) 
 GLES20.glViewport(0, 0, (float)width, (float)height);
 Matrix.setIdentityM(mProjectionMatrix, 0);
 Matrix.perspectiveM(mProjectionMatrix, 0, mFOV_Y, DisplayConst.SCREEN_RATIO, mZNear, DisplayConst.GLASSES_FAR_PLANE);
 // mFOV_Y: 12.0f (degrees); screenRatio: 1.8f; nearPlane: 0.01f; farPlane: 100.0f (meters);

However, even with the theoretical FOV_Y of the AR headset I am using, the issue is still there. I need to give a really low value (+-3°) to approximate something correct, which troubles me because I think it does not correspond to the real value.
For the OpenGL camera, I update at each drawing step both the eyePos and LookAt parameters according to the pose of the AR headset, and this part appears to work as expected.

Did I miss something I the view or projection matrix which could cause this kind of effect ?