<li><label class="tree-toggle nav-header">{{ category.name }}</label>
    <ul class="nav nav-list tree">
    {% for child in category.active_children %}
        {% with category=child template_name="three_d_viewer/treenode.html" %}
            <ul style="list-style: none;">
                {% include template_name %}
            </ul>
        {%endwith%}
    {% endfor %}
    {% for sample in category.active_samples %}
            <li><a href={% url sample.url sample.id %}>{{ sample.name }}</a></li>
    {% endfor %}
    </ul>
</li>