for the model texture/vertices depth problem, it seems to be fixed (not 100% sure) by adding this "glEnable(GL_DEPTH_TEST);" in the native code before calling jpct render code.. but still need to test more to confirm that since it is very difficult to rotate out the 3d model and see that in the view coz i am experimenting with the matrix.

Currently i am testing the matrix returned by an inverse function which "supposedly" will be the eye view (camera) of the model if I pass in the modelview matrix but without much success. So are you saying I should set those values to "0" (except the last 1.0) in the last row?

Is jpct matrix row-major or column major? I am not sure if the 4x4 OpenGL matrix returned by Qualcomm is ready to use..

Here is the qualcomm library util function for getting an inverse:

SampleMath::Matrix44FInverse(QCAR::Matrix44F& m)
{
    QCAR::Matrix44F r;

    float det = 1.0f / Matrix44FDeterminate(m);

    r.data[0]   = m.data[6]*m.data[11]*m.data[13] - m.data[7]*m.data[10]*m.data[13]
                + m.data[7]*m.data[9]*m.data[14] - m.data[5]*m.data[11]*m.data[14]
                - m.data[6]*m.data[9]*m.data[15] + m.data[5]*m.data[10]*m.data[15];

    r.data[4]   = m.data[3]*m.data[10]*m.data[13] - m.data[2]*m.data[11]*m.data[13]
                - m.data[3]*m.data[9]*m.data[14] + m.data[1]*m.data[11]*m.data[14]
                + m.data[2]*m.data[9]*m.data[15] - m.data[1]*m.data[10]*m.data[15];

    r.data[8]   = m.data[2]*m.data[7]*m.data[13] - m.data[3]*m.data[6]*m.data[13]
                + m.data[3]*m.data[5]*m.data[14] - m.data[1]*m.data[7]*m.data[14]
                - m.data[2]*m.data[5]*m.data[15] + m.data[1]*m.data[6]*m.data[15];

    r.data[12]  = m.data[3]*m.data[6]*m.data[9] - m.data[2]*m.data[7]*m.data[9]
                - m.data[3]*m.data[5]*m.data[10] + m.data[1]*m.data[7]*m.data[10]
                + m.data[2]*m.data[5]*m.data[11] - m.data[1]*m.data[6]*m.data[11];

    r.data[1]   = m.data[7]*m.data[10]*m.data[12] - m.data[6]*m.data[11]*m.data[12]
                - m.data[7]*m.data[8]*m.data[14] + m.data[4]*m.data[11]*m.data[14]
                + m.data[6]*m.data[8]*m.data[15] - m.data[4]*m.data[10]*m.data[15];

    r.data[5]   = m.data[2]*m.data[11]*m.data[12] - m.data[3]*m.data[10]*m.data[12]
                + m.data[3]*m.data[8]*m.data[14] - m.data[0]*m.data[11]*m.data[14]
                - m.data[2]*m.data[8]*m.data[15] + m.data[0]*m.data[10]*m.data[15];

    r.data[9]   = m.data[3]*m.data[6]*m.data[12] - m.data[2]*m.data[7]*m.data[12]
                - m.data[3]*m.data[4]*m.data[14] + m.data[0]*m.data[7]*m.data[14]
                + m.data[2]*m.data[4]*m.data[15] - m.data[0]*m.data[6]*m.data[15];

    r.data[13]  = m.data[2]*m.data[7]*m.data[8] - m.data[3]*m.data[6]*m.data[8]
                + m.data[3]*m.data[4]*m.data[10] - m.data[0]*m.data[7]*m.data[10]
                - m.data[2]*m.data[4]*m.data[11] + m.data[0]*m.data[6]*m.data[11];

    r.data[2]   = m.data[5]*m.data[11]*m.data[12] - m.data[7]*m.data[9]*m.data[12]
                + m.data[7]*m.data[8]*m.data[13] - m.data[4]*m.data[11]*m.data[13]
                - m.data[5]*m.data[8]*m.data[15] + m.data[4]*m.data[9]*m.data[15];

    r.data[6]   = m.data[3]*m.data[9]*m.data[12] - m.data[1]*m.data[11]*m.data[12]
                - m.data[3]*m.data[8]*m.data[13] + m.data[0]*m.data[11]*m.data[13]
                + m.data[1]*m.data[8]*m.data[15] - m.data[0]*m.data[9]*m.data[15];

    r.data[10]  = m.data[1]*m.data[7]*m.data[12] - m.data[3]*m.data[5]*m.data[12]
                + m.data[3]*m.data[4]*m.data[13] - m.data[0]*m.data[7]*m.data[13]
                - m.data[1]*m.data[4]*m.data[15] + m.data[0]*m.data[5]*m.data[15];

    r.data[14]  = m.data[3]*m.data[5]*m.data[8] - m.data[1]*m.data[7]*m.data[8]
- m.data[3]*m.data[4]*m.data[9] + m.data[0]*m.data[7]*m.data[9]
                + m.data[1]*m.data[4]*m.data[11] - m.data[0]*m.data[5]*m.data[11];

    r.data[3]   = m.data[6]*m.data[9]*m.data[12] - m.data[5]*m.data[10]*m.data[12]
                - m.data[6]*m.data[8]*m.data[13] + m.data[4]*m.data[10]*m.data[13]
                + m.data[5]*m.data[8]*m.data[14] - m.data[4]*m.data[9]*m.data[14];

    r.data[7]  = m.data[1]*m.data[10]*m.data[12] - m.data[2]*m.data[9]*m.data[12]
                + m.data[2]*m.data[8]*m.data[13] - m.data[0]*m.data[10]*m.data[13]
                - m.data[1]*m.data[8]*m.data[14] + m.data[0]*m.data[9]*m.data[14];

    r.data[11]  = m.data[2]*m.data[5]*m.data[12] - m.data[1]*m.data[6]*m.data[12]
                - m.data[2]*m.data[4]*m.data[13] + m.data[0]*m.data[6]*m.data[13]
                + m.data[1]*m.data[4]*m.data[14] - m.data[0]*m.data[5]*m.data[14];

    r.data[15]  = m.data[1]*m.data[6]*m.data[8] - m.data[2]*m.data[5]*m.data[8]
                + m.data[2]*m.data[4]*m.data[9] - m.data[0]*m.data[6]*m.data[9]
                - m.data[1]*m.data[4]*m.data[10] + m.data[0]*m.data[5]*m.data[10];

    for (int i = 0; i < 16; i++)
        r.data *= det;
   
    return r;
}

actually instead of using "fillDump" I should use "setDump" i guess. If i use that, I can see the model moving relatively kind of, but the whole model is upside down. The relative movement is probably not correct although at least it moves relative to my phone and the tracked target. Also it cannot handle the "depth" part, meaning if I pull my phone away, the model doesn't know zoom out.. what could be wrong??

those matrices are created by an AR engine, so I guess they are created based on the "target image" tracked by the camera and the phone orientation (I am using jpct for android). I have no access to those logic that creates those matrices. So do you think it is still possible to apply that modelview matrix to the jpct camera? If not, is there any backdoor way to directly apply this matrix at the low level code at all? coz the AR engine pretty much act like the Camera already in my case, all I need from jpct is mainly the ability to load and render models pretty much.. although I don't prefer this hacky way and still want to somehow make use of the jpct camera object of course.

thanks a lot for replying!