UWSim updates: TF publisher, trajectory trails, bullet 2.82

UWSim trunk has been updated with some updates that are worthy to be briefly described. TF publisher offers a simple interface to publish via ROS TF the frames of every object, vehicle, vehicle part and sensor present in the scene in a tree structure with virtual world root. Objects publishing is optional and rootName can be configured, vehicle's parts use a prefix with the vehicle's name to avoid collision on tf identifiers. To add it the following lines should be added in the rosinterfaces block of the XML config file.

  <WorldToROSTF>
    <rootName> world </rootName>
    <enableObjects> 1 </enableObjects>
    <rate>10</rate>
  </WorldToROSTF>

Trajectory trails have been completely re-implemented so they can represent object movements and vehicle parts movements. Additionally trajectory trails can be hidden / displayed pressing “t” key. Instead of adding a config line inside vehicle XML block, trajectory trails are configured using showTrajectory blocks inside simParams as the following example shows:

  <showTrajectory>
    <target>girona500</target>
    <color>
      <r>1.0</r>
      <g>0.0</g>
      <b>0.0</b>
    </color>
    <lineStyle> 1 </lineStyle>
    <timeWindow> 30 </timeWindow>
  </showTrajectory>

Only target field is required to add a trajectory trail configuring the object that will draw a trajectory while moving. The other tags allows us to decide color lineStyle, where 1 is continuous line 2,3,4 are different kinds of dashed lines and timeWindow, which is an option to limit the trail to the last X seconds.

Finally, last (but not least!) update is the change of the bullet physics solver to Dantzig and bullet 2.82. This changes lead to better contact physics as shown in our tests heading to a better manipulation simulation.