to create
    segments on the offset curve.  This means that, if there is a
    sharp bend in the main curve and the offset is large, the
    segments in the offset curve may become long.  
    This may result in a visibly non-smooth offset curve, as shown 
    below.
  </p>

    <p class="img">
      <img src="figure/render-lumpy-1.svg" width="30%">
    </p>
    <p>
    This problem could be avoided if the offset curve function was
    evaluated directly, but this approach has not even been attempted 
    