RealSenseDevice::GetCameraPos

void RealSenseDevice::GetCameraPos(Point2i screenPoint, Point3f &cameraPoint)
{
  if(screenPoint.x >= m_nColorSize.width || screenPoint.y >= m_nColorSize.height || screenPoint.y < 0 || screenPoint.x < 0)
  {
  cameraPoint.x = -1;
  cameraPoint.y = -1;
  cameraPoint.z = -1;
  return ;
  }

  int nIndex = screenPoint.x + screenPoint.y*m_nColorSize.width;
  RealSense::PointF32 pos = m_uvmap[nIndex];
  if(pos.x != -1 && pos.y != -1)
  {
  nIndex = m_uvmap[nIndex].x*m_nDepthSize.width + m_uvmap[nIndex].y*m_nDepthSize.height * m_nDepthSize.width;


  cameraPoint.x =  m_vertices[nIndex].x;
  cameraPoint.y =  m_vertices[nIndex].y;
  cameraPoint.z =  m_vertices[nIndex].z;
  }
}