span class="op">(</span><span class="cn">FALSE</span><span class="op">)</span> <span class="op">{</span></span></span>
<span class="r-in"><span><span class="co"># the website https://touchterrain.geol.iastate.edu/ allows a download</span></span></span>
<span class="r-in"><span><span class="co"># of a 3d printable terrain model. For an example we suggest to download a file from there.</span></span></span>
<span class="r-in"><span><span class="va">gc</span> <span class="op">&lt;-</span> <span class="fu">rgl</