ep" title="mujoco_py.MjSim.step"><code class="xref py py-meth docutils literal"><span class="pre">step()</span></code></a>.
Buffers will be swapped only once per step.</p>
</div></blockquote>
<p><strong>udd_callback</strong> : fn(<a class="reference internal" href="#mujoco_py.MjSim" title="mujoco_py.MjSim"><code class="xref py py-class docutils literal"><span class="pre">MjSim</span></code></a>) -&gt; dict</p>
<blockquote class="last">
<div><p>Optional callback for user-defined dynamics. At every call to
<a