title: Is there a way of visualising a line in drake visualizer
body: <p>I am currently working with the compass-gait example. I am trying to visualise a planned path for a robot. Is there a way to visualise a few lines dynamically during the simulation on the visualizer as the robot traces a path? </p>
  
  <p>I am looking into publishing lcm messages directly <a href="https://openhumanoids.github.io/director/user_guide/tree_viewer_interface.html#viewer-tree" rel="nofollow noreferrer">from here</a>, but I am finding it a little hard to get the right sequence. Is there a sub-module I can check to get a better idea about this?</p>