public void packRobotComCopSeries(ArrayList<Point3d> outCom, ArrayList<Point3d> outCop) {
    outCom.clear();
    outCop.clear();
    for (int i = 0; i < selectedFrames.length; i++) {
      dataBuffer.setIndexButDoNotNotifySimulationRewoundListeners(selectedFrames[i]);
      // model predicted CoM
      robot.update(); // this pull data from dataBuffer magically through YoVariables
      Point3d modelCoM = new Point3d();
      robot.computeCenterOfMass(modelCoM);
      outCom.add(modelCoM);

      // sensedCoP
      Point3d sensedCoP =
          new Point3d(
              dataBuffer.getVariable("sensedCoPX").getValueAsDouble(),
              dataBuffer.getVariable("sensedCoPY").getValueAsDouble(),
              dataBuffer.getVariable("sensedCoPZ").getValueAsDouble());
      outCop.add(sensedCoP);
    }
  }