libgazebo_ros_diff_drive publishes tf based on wall clock time instead of sim time

I am using multiple turtlebot3 robots in my simulation with gazebo. The differential time plugin publishes a transform between the `odom` frame and the `base_footprint` frame. I also have a plugin which publishes the ground truth pose of the turtlebot3 `libgazebo_ros_p3d.so`. I want to generate transformations between multiple turtlebot3 robots and to do this I have a seperate node which broadcasts transform between the `base_link` frame and the `world` frame. The problem is that the `base_link` to `world` transformations are published with the `sim_time` as I intend but for some reason the transformations between the `base_footprint` and `odom` frame are published with my computers clock time. Because of this I cannot generate transformations between the `odom` frame and the `world` frame. Heres what I would like my tf tree to be: -------------------- world -------------------- tb1/base_link tb2/base_link tb3/base_link | | | tb1/base_footprint tb2/base_footprint tb3/base_footprint | | | tb1/odom tb2/odom tb3/odom Heres the snippets of code: The main launch file: The gazebo plugins in the turtlebot's xacro file: cmd_velodomodomworldtruebase_footprintfalsetruetruefalse30wheel_left_jointwheel_right_joint0.2870.066110natrue50.0base_linkground_truth_pose0.01world0 0 00 0 0 Turtlebot3.launch `base_link` to `world` tf broadcaster: #!/usr/bin/env python import rospy import sys import tf from nav_msgs.msg import Odometry def update_tf(data): transform_from = "{}/base_footprint".format(ns) transform_to = "world" pos = data.pose.pose.position ori = data.pose.pose.orientation orientation = [ori.x, ori.y, ori.z, ori.w] position = [pos.x, pos.y, pos.z] br = tf.TransformBroadcaster() print rospy.Time.now() br.sendTransform(position, orientation, rospy.Time.now(), transform_from, transform_to) if __name__ == '__main__': ns = sys.argv[1] rospy.init_node("tf_broadcaster_{}".format(ns.split('_')[1])) pose_subscriber = rospy.Subscriber("{}/ground_truth_pose".format(ns), Odometry, update_tf) rospy.spin() Here's the output from the `/tf` topic: transforms: - header: seq: 0 stamp: secs: 2764768896 nsecs: 32752 frame_id: "burger_2/odom" child_frame_id: "burger_2/base_footprint" transform: translation: x: 2.20744910982 y: 2.01895292219 z: -0.000612418868214 rotation: x: -0.000874178201541 y: -0.000801260462534 z: 0.999653654558 w: -0.0262900118476 --- transforms: - header: seq: 0 stamp: secs: 102756 nsecs: 880000000 frame_id: "world" child_frame_id: "burger_1/base_footprint" transform: translation: x: 1.32845899318 y: 0.92220015314 z: -0.0104010663862 rotation: x: 0.000706580835481 y: 0.000460995693433 z: 0.0407422461322 w: -0.9991693338 --- `rosrun tf view_frams` gives the fowwing output: Warning: TF_OLD_DATA ignoring data from the past for frame burger_2/base_footprint at time 2.76477e+09 according to authority /gazebo Possible reasons are listed at http://wiki.ros.org/tf/Errors%20explained at line 277 in /tmp/binarydeb/ros-kinetic-tf2-0.5.18/src/buffer_core.cpp Warning: TF_OLD_DATA ignoring data from the past for frame burger_2/base_footprint at time 2.76477e+09 according to authority /gazebo Possible reasons are listed at http://wiki.ros.org/tf/Errors%20explained at line 277 in /tmp/binarydeb/ros-kinetic-tf2-0.5.18/src/buffer_core.cpp `roswtf` ouput: Loaded plugin tf.tfwtf No package or stack in context ================================================================================ Static checks summary: No errors or warnings ================================================================================ Beginning tests of your ROS graph. These may take awhile... analyzing graph... ... done analyzing graph running graph rules... ... done running graph rules running tf checks, this will take a second... ... tf checks complete Online checks summary: Found 2 warning(s). Warnings are things that may be just fine, but are sometimes at fault WARNING The following node subscriptions are unconnected: * /gazebo: * /gazebo/set_model_state * /gazebo/set_link_state WARNING Received out-of-date/future transforms: * receiving transform from [/tf_broadcaster_1] that differed from ROS time by -1.38s * receiving transform from [/gazebo] that differed from ROS time by 4001227263.39s I even tried passing `` in the turtlebot's launch file but in vain ... Any help is appreciated, thanks in advance