public void setToOrigin(TransMatrix kToOrigin) {
   m_kToOrigin = convertTo4D(kToOrigin);
   m_kToOriginInv.Inverse(m_kToOrigin);
 }
 public void setFromOrigin(TransMatrix kFromOrigin) {
   m_kFromOrigin = convertTo4D(kFromOrigin);
   m_kFromOriginInv.Inverse(m_kFromOrigin);
 }