particle and a wall.">ContactPW</a></code> object representing the contact point(s). </td></tr>
    <tr><td class="paramname">dt</td><td>The time step size for the simulation. </td></tr>
  </table>
  </dd>
</dl>

<p>Reimplemented in <a class="el" href="classnetdem_1_1_hertz_mindlin.html#aaf1f383d0c77f5129b3b6f2911467905">netdem::HertzMindlin</a>, <a class="el" href="classnetdem_1_1_linear_spring.html#a917b9afdfec8c1a563178f8a588c302b">netdem::LinearSpring</a>, and <a class="el" href="classnetdem_1_1_volume_