The problem I face is that as I rotate the camera around the y axis to face negative z, looking up or down (rotating around the camera's right vector) appears to tilt the camera around the global x axis in the opposite direction, rather than translating the relative to the camera.

The problem I face is that as I rotate the camera around the y axis to face negative z, looking up or down (rotating around the camera's right vector) appears to tilt the camera around the global x axis in the opposite direction, rather than translating relative to the camera.

I have so far used these tutorials above however I have a bug which I cannot work out how to fix.

// Quaternion Normalize Method.
    Quaternion<TValue> normalize() const{
                TValue magnitude = getMagnitude();
                auto normalizedValues = array<TValue, 4>();
                for (int i = 0; i < 4; i++){
                    normalizedValues[i] = m_values[i] / magnitude;
                }
                return Vector<dimensions, TValue>(normalizedValues);
            }

// Quaternion multiplication method.
    Quaternion<TValue>& operator*=(const Quaternion<TValue>& rhs) {
                float x, y, z, w;
                x = m_values[W] * rhs[X] + m_values[X] * rhs[W] + m_values[Y] * rhs[Z] - m_values[Z] * rhs[Y];
                y = m_values[W] * rhs[Y] - m_values[X] * rhs[Z] + m_values[Y] * rhs[W] + m_values[Z] * rhs[X];
                z = m_values[W] * rhs[Z] + m_values[X] * rhs[Y] - m_values[Y] * rhs[X] + m_values[Z] * rhs[W];
                w = m_values[W] * rhs[W] - m_values[X] * rhs[X] - m_values[Y] * rhs[Y] - m_values[Z] * rhs[Z];
                
                m_values[X] = x;
                m_values[Y] = y;
                m_values[Z] = z;
                m_values[W] = w;
                
                return *this;
            };

        Quaternion<TValue> conjugate() const{
            return Quaternion({ { -m_values[X], -m_values[Y], -m_values[Z], m_values[W] } });
        };

// Quaternion rotation method
        static Quaternion<TValue> rotation(Vector<3, TValue> axis, TValue angle){
            float x, y, z, w;
            TValue halfTheta = angle / 2.0f;
            TValue sinHalfTheta = sin(halfTheta);
            return Quaternion<TValue>({ { axis[X] * sinHalfTheta, axis[Y] * sinHalfTheta, axis[Z] * sinHalfTheta, cos(halfTheta) } });
        };

// Vector rotate method
    Vector<dimensions, TValue> rotate(const Vector<3, TValue> axis, float angle){
                Quaternion<TValue> R = Quaternion<TValue>::rotation(axis, angle);
                Quaternion<TValue> V = (*this);
                Vector<dimensions, TValue> result = R * V * R.conjugate();
                return result;
            }

// Camera rotate method.
void Camera::rotate(Vector<3,float> axis, float angle){
        setLookAt(m_target.rotate(axis, angle), m_up.rotate(axis, angle));
    }

// Camera setLookAt method.
    void Camera::setLookAt(Vector<3, float> target, Vector<3, float> up){
        Vector<3, float> newUp = up.normalize();
        Vector<3, float> newTarget = target.normalize();
        if (newUp != m_up || newTarget != m_target){
            m_up = newUp;
            m_target = newTarget;
            
            
            m_right = (m_up * m_target).normalize();
        
            m_up = m_target * m_right;
            
            m_uvn = Matrix<4, float>::identity();
            
            m_uvn[0][0] = m_right[Dimensions::X];
            m_uvn[1][0] = m_right[Dimensions::Y];
            m_uvn[2][0] = m_right[Dimensions::Z];
            
            m_uvn[0][1] = m_up[Dimensions::X];
            m_uvn[1][1] = m_up[Dimensions::Y];
            m_uvn[2][1] = m_up[Dimensions::Z];

            m_uvn[0][2] = m_target[Dimensions::X];
            m_uvn[1][2] = m_target[Dimensions::Y];
            m_uvn[2][2] = m_target[Dimensions::Z];
        
 
            setViewMatrix(m_uvn * m_translation);
        }
    };

// Taken from game update method.
Vector<2, double> offset = getMousePosition() - m_screenCentre;
if (offset.getMagnitudeSquared() > 0.00001){
    float dy = offset[Dimensions::X] * (3.1415),
          dx = offset[Dimensions::Y] * (3.1415);
    m_camera.rotate(Vector<3, float>({ { 0, -1, 0 } }), dy);
    m_camera.rotate(Vector<3, float>(m_camera.getXAxis()), dx);
    setMousePosition(m_screenCentre);
}

I have so far used these tutorials below however I have a bug which I cannot work out how to fix.

// Quaternion Normalize Method.
Quaternion<TValue> normalize() const {
  TValue magnitude = getMagnitude();
  auto normalizedValues = array<TValue, 4>();
  for (int i = 0; i < 4; i++){
    normalizedValues[i] = m_values[i] / magnitude;
  }
  return Vector<dimensions, TValue>(normalizedValues);
}

// Quaternion multiplication method.
Quaternion<TValue>& operator*=(const Quaternion<TValue>& rhs) {
  float x, y, z, w;
  x = m_values[W] * rhs[X] + m_values[X] * rhs[W] + m_values[Y] * rhs[Z] - m_values[Z] * rhs[Y];
  y = m_values[W] * rhs[Y] - m_values[X] * rhs[Z] + m_values[Y] * rhs[W] + m_values[Z] * rhs[X];
  z = m_values[W] * rhs[Z] + m_values[X] * rhs[Y] - m_values[Y] * rhs[X] + m_values[Z] * rhs[W];
  w = m_values[W] * rhs[W] - m_values[X] * rhs[X] - m_values[Y] * rhs[Y] - m_values[Z] * rhs[Z];
  
  m_values[X] = x;
  m_values[Y] = y;
  m_values[Z] = z;
  m_values[W] = w;
  
  return *this;
};

Quaternion<TValue> conjugate() const{
  return Quaternion({ { -m_values[X], -m_values[Y], -m_values[Z], m_values[W] } });
};

// Quaternion rotation method
static Quaternion<TValue> rotation(Vector<3, TValue> axis, TValue angle){
  float x, y, z, w;
  TValue halfTheta = angle / 2.0f;
  TValue sinHalfTheta = sin(halfTheta);
  return Quaternion<TValue>({ {
    axis[X] * sinHalfTheta, 
    axis[Y] * sinHalfTheta, 
    axis[Z] * sinHalfTheta, 
    cos(halfTheta) } });
};

// Vector rotate method
Vector<dimensions, TValue> rotate(const Vector<3, TValue> axis, float angle){
  Quaternion<TValue> R = Quaternion<TValue>::rotation(axis, angle);
  Quaternion<TValue> V = (*this);
  Vector<dimensions, TValue> result = R * V * R.conjugate();
  return result;
}

// Camera rotate method.
void Camera::rotate(Vector<3,float> axis, float angle){
  setLookAt(m_target.rotate(axis, angle), m_up.rotate(axis, angle));
}

// Camera setLookAt method.
void Camera::setLookAt(Vector<3, float> target, Vector<3, float> up){
  Vector<3, float> newUp = up.normalize();
  Vector<3, float> newTarget = target.normalize();
  if (newUp != m_up || newTarget != m_target){
    m_up = newUp;
    m_target = newTarget;
    
    
    m_right = (m_up * m_target).normalize();
  
    m_up = m_target * m_right;
    
    m_uvn = Matrix<4, float>::identity();
    
    m_uvn[0][0] = m_right[Dimensions::X];
    m_uvn[1][0] = m_right[Dimensions::Y];
    m_uvn[2][0] = m_right[Dimensions::Z];
    
    m_uvn[0][1] = m_up[Dimensions::X];
    m_uvn[1][1] = m_up[Dimensions::Y];
    m_uvn[2][1] = m_up[Dimensions::Z];

    m_uvn[0][2] = m_target[Dimensions::X];
    m_uvn[1][2] = m_target[Dimensions::Y];
    m_uvn[2][2] = m_target[Dimensions::Z];
  
    setViewMatrix(m_uvn * m_translation);
  }
}; 


// Taken from game update method.
Vector<2, double> offset = getMousePosition() - m_screenCentre;
if (offset.getMagnitudeSquared() > 0.00001){
  float dy = offset[Dimensions::X] * (3.1415),
  dx = offset[Dimensions::Y] * (3.1415);
  m_camera.rotate(Vector<3, float>({ { 0, -1, 0 } }), dy);
  m_camera.rotate(Vector<3, float>(m_camera.getXAxis()), dx);
  setMousePosition(m_screenCentre);
}

I am trying to implement a quaternion camera in openGL 3.3.

I have so far used these tutorials above however I have a bug which I cannot work out how to fix. http://ogldev.atspace.co.uk/www/tutorial13/tutorial13.html http://www.gamedev.net/page/resources/_/technical/math-and-physics/a-simple-quaternion-based-camera-r1997

I am trying to implement a quaternion camera in OpenGL 3.3.

I have so far used these tutorials above however I have a bug which I cannot work out how to fix.

• http://ogldev.atspace.co.uk/www/tutorial13/tutorial13.html
• http://www.gamedev.net/page/resources/_/technical/math-and-physics/a-simple-quaternion-based-camera-r1997