OpenGL Камера перемещающаяся над текстурой

#define LG_FOVY      15.0
#define LG_NEAR_DIST 0.0001
#define M_DEG_TO_RAD M_PI/180

CAMERA::CAMERA(QWidget *parent)
    : Widget(parent)
{
    initCamera(0.0, 0.0, 1.0);
}



void CAMERA::initCamera(GLdouble scnx, GLdouble scny, GLdouble scnz)
{
    //! Инициализация матрицы
    matrix.xx = 1.0; matrix.xy = 0.0; matrix.xz = 0.0; matrix.tx = 0.0;
    matrix.yx = 0.0; matrix.yy = 1.0; matrix.yz = 0.0; matrix.ty = 0.0;
    matrix.zx = 0.0; matrix.zy = 0.0; matrix.zz = 1.0; matrix.tz = 0.0;
    matrix.xw = 0.0; matrix.yw = 0.0; matrix.zw = 0.0; matrix.tw = 1.0;

    scnmove.x = scnx;
    scnmove.y = scny;
    scnmove.z = scnz;

    // Обновление модельно-видовой матрицы 
    matrix.tx = -scnmove.x;
    matrix.ty = -scnmove.y;
    matrix.tz = -scnmove.z;
}

void CAMERA::viewProjection()
{
    GLdouble ratio       = (GLdouble)Widget->width() / Widget->height(),
             TAN_FOVY    = tan(LG_FOVY * M_DEG_TO_RAD),
             LG_FAR_DIST = qMin(0.5 / TAN_FOVY, 0.5 / ratio / TAN_FOVY),
             fH          = TAN_FOVY * LG_NEAR_DIST,
             fW          = fH * ratio;

    glViewport(0, 0, Widget->width(), Widget->height());

    // Генерация матрицы проекций
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-fW, fW, -fH, fH, LG_NEAR_DIST, LG_FAR_DIST);

    // Генерация модельно-видовой матрицы
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glMultMatrixd((GLdouble*)&matrix);
}
....
void MyGLWidget::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    camera.viewProjection();

    glPointSize(3.0);qglColor(Qt::red);
    glBegin(GL_POINTS);
    glVertex3d((GLdouble)(camera.scnmove.x),
               (GLdouble)(camera.scnmove.y),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.x+camera.scnmove.w/2),
               (GLdouble)(camera.scnmove.y+camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.x+camera.scnmove.w/2),
               (GLdouble)(camera.scnmove.y-camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.x-camera.scnmove.w/2),
               (GLdouble)(camera.scnmove.y-camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.x-camera.scnmove.w/2),
               (GLdouble)(camera.scnmove.y+camera.scnmove.h/2),
               (GLdouble)(0.0));
    glEnd();

    glPointSize(3.0);qglColor(Qt::magenta);
    glBegin(GL_POINTS);
    glVertex3d((GLdouble)(0.0),
               (GLdouble)(0.0),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.w/2),
               (GLdouble)(camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(camera.scnmove.w/2),
               (GLdouble)(-camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(-camera.scnmove.w/2),
               (GLdouble)(-camera.scnmove.h/2),
               (GLdouble)(0.0));
    glVertex3d((GLdouble)(-camera.scnmove.w/2),
               (GLdouble)( camera.scnmove.h/2),
               (GLdouble)(0.0));
    glEnd();
}