summary-table-tab2 method-summary-table-tab4"><code>void</code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#perpendicular()" class="member-name-link">perpendicular</a>()</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Calculate an arbitrary unit vector perpendicular to this,
 this vector must be normalized.</div>
</div>
<div cl