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<a name="Polyline-sweeps"></a>Next:&nbsp;<a rel="next" accesskey="n" href="Nested-sweeps.html#Nested-sweeps">Nested sweeps</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="Point-sweeps.html#Point-sweeps">Point sweeps</a>,
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<h4 class="subsection">2.7.2 Polyline sweeps</h4>

<p>Sweeping a polyline produces a
<a name="index-line-sweep-105"></a><a name="index-swept-line-106"></a><a name="index-surface-107"></a>surface composed of many faces. 
<a name="index-faces-108"></a>The unbroken helix in the
example <a href="Helix-with-cull-set-false-then-true.html#Helix-with-cull-set-false-then-true">Helix with cull set false then true</a> is produced by this
code (plus a surrounding <tt>put</tt> rotation to make an interesting
view; this has been omitted). 
<a name="index-def-109"></a><a name="index-sweep-110"></a><a name="index-rotate-111"></a><a name="index-translate-112"></a><a name="index-cull-113"></a><a name="index-linewidth-114"></a>
<pre class="verbatim">
  def K [0,0,1]
  sweep[cull=false] {
    60, 
    rotate(10, (0,0,0), [K]) then translate(1/6 * [K]) 
  } line[linewidth=2pt](-1,0)(1,0)
</pre>
Again, 60 segments of the helix
<a name="index-helix-115"></a>are produced by connecting 61
instances of the swept line.  Options
<a name="index-options_002c-sweep-116"></a>applied to the sweep, here
<tt>cull=false</tt>, are treated as options for the generated polygon
or polyline.  Options of the swept line itself, here
<tt>linewidth=2pt</tt>, are ignored, though with a warning. This
<tt>def</tt> is a <dfn>vector</dfn> definition,
<a name="index-definition_002c-vector-117"></a><a name="index-vector-definition-118"></a>which must be referenced
with square brackets, e.g. <tt>[foo]</tt>. 
<a name="index-reference_002c-vector-119"></a><a name="index-_005bfoo_005d_0040r_007b_002c-vector-reference_007d-120"></a>

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