Documentation
Walker System Basics
The Simulator Walker system allows to spawn few types of Walkers and also allows making Walkers that are either Stationary, Roam randominly across the map or be set to follow given path. Any spawned Walker can also be overriden to Walk or teleported to given location.
The Simulator has following types of Walkers.
| type | model |
walker | Reindeer |
When spawning a Walker you need to define few parameters:
WalkerSpeed - Speed of the Walker
WalkerAction - What is the Walker action type: Stationary / Roaming / Follow path
WalkerEndAction - What does the Walker do when destionation is reached: Destroy / Repeat from start / Go backwards / Stop until destroyed manually
When spawning Walker with WalkerAction of Stationary or Roaming, WalkerEndAction is ignored.
Spawning Walkers through User Interface
- Open Asset Placement tool from right top menu toolbar menu
- Open Walker tab
- Select Walker you want to spawn
Select desired Walker parameters:
4.1 Select Walker Action
4.2 Select Movement End Action
4.3 Select Walker Speed
- Select position you want Walker to spawned and left click. If selected Walker Action is Follow path, you need to select at least two points and then you can click Spawn Walker.
Exporting Walker(s) into JSON file(s) through user interface
After spawning Walker or multiple Walker, you can export all of them into separate JSON files by clicking "Export Walkers" button in the Walker user interface.
Walker(s) will be exported into SIMULATOR_ROOT/Data/ExportedJsonFiles directory and the JSON file(s) will include Walker type and its current parameters.
Exporting Walker(s) into JSON file(s) through ROS
Walker(s) will be exported into SIMULATOR_ROOT/Data/ExportedJsonFiles directory and the JSON file(s) will include Walker type and its current parameters.
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "ExportWalkers" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: ExportWalkers" --once
Destroying Walkers through User Interface
To destroy all Walkers:
- Open Asset Placement tool from right top menu toolbar menu
- Open Walker tab
- Click "Delete All" and then click "Confirm".
To destroy individual Walker:
- Right click Walker
- Click Remove from the context menu
Destroying Walkers through ROS
To destroy all Walkers through ROS:
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "DestroyAllWalkers" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: DestroyAllWalkers" --once
To Destroy individual Walker through ROS:
# ROS 1 - where 'reindeer' is the ID of the Walker
rostopic pub /Agrarsense/Commands std_msgs/String "destroyobjectbyid reindeer" --once
# ROS 2 - where 'reindeer' is the ID of the Walker
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: destroyobjectbyid reindeer" --once
Spawning Stationary Walker through ROS
You can spawn Walker through ROS by using SpawnObjects command which takes .json file path.
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_stationary.json" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_stationary.json" --once
The .json file structure should look something like this:
{
"objects":
[
{
"type": "walker",
"model": "Reindeer",
"id": "reindeer",
"parameters":
{
"walkerAction": "Stationary",
"spawnPoint":
{
"x": 0.0,
"y": 0.0,
"z": 100.0,
"roll": 0.0,
"pitch": 0.0,
"yaw": 0.0
}
}
}
]
}
Spawning Roaming Walker through ROS
You can spawn Walker through ROS by using SpawnObjects command which takes .json file path.
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_roaming.json" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_roaming.json" --once
The .json file structure should look something like this:
{
"objects":
[
{
"type": "walker",
"model": "Reindeer",
"id": "reindeer",
"teleportSpectator": "false",
"followObject": "false",
"parameters":
{
"walkerSpeed": "50",
"walkerAction": "Roaming",
"spawnPoint":
{
"x": 0.0,
"y": 0.0,
"z": 2000.0,
"roll": 0.0,
"pitch": 0.0,
"yaw": 0.0
}
}
}
]
}
Spawning "Follow path" Walker through ROS
You can spawn Walker through ROS by using SpawnObjects command which takes .json file path.
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_roaming.json" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: SpawnObjects C:/Agrarsense/Examples/ExampleJsonFiles/walker_roaming.json" --once
The .json file structure should look something like this:
{
"objects":
[
{
"type": "walker",
"model": "Reindeer",
"id": "reindeer",
"teleportSpectator": "false",
"followObject": "false",
"parameters":
{
"walkerSpeed": "50",
"walkerAction": "FollowPath",
"endAction": "RepeatFromBeginning",
"points":
{
"point0":
{
"x": 0.0,
"y": 0.0,
"z": 2000.0,
"roll": 0.0,
"pitch": 0.0,
"yaw": 0.0
},
"point1":
{
"x": -3360.0,
"y": 7750.0,
"z": 1430,
"roll": 0.0,
"pitch": 0.0,
"yaw": 0.0
},
"point2":
{
"x": -3350.0,
"y": 7100.0,
"z": 1430.0,
"roll": 0.0,
"pitch": 0.0,
"yaw": 0.0
}
}
}
}
]
}
Override Walker to move towards certain position
To override a Walker to start moving towards certain position you can use either ROS Command MoveWalkerTo or MoveWalkerToAndDestroy command.
MoveWalkerTo Command will command the Walker to start moving towards given position, and if Walker arrives at given position, the walker will stop until it is destroyed or new position is given.
Both of these commands take in ID X,Y,Z or ID X,Y,Z,Pitch,Roll,Yaw
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "MoveWalkerTo ID X,Y,Z" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: MoveWalkerTo ID X,Y,Z" --once
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "MoveWalkerTo reindeer 0,0,0" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: MoveWalkerTo reindeer 0,0,0" --once
MoveWalkerToAndDestroy does almost the same as MoveWalkerTo command but if Walker arrives at given position it will destroy itself automatically.
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "MoveWalkerToAndDestroy reindeer 0,0,0" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: MoveWalkerToAndDestroy reindeer 0,0,0" --once
Note. The Simulator does check whether given path is reachable or not.
Pausing and resuming Walker through ROS
You can pause/resume Walker movement by using PauseWalker ID or ResumeWalker ID ROS Command like below:
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "PauseWalker reindeer" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: PauseWalker reindeer" --once
# ROS1
rostopic pub /Agrarsense/Commands std_msgs/String "ResumeWalker reindeer" --once
# ROS2
ros2 topic pub /Agrarsense/Commands std_msgs/String "data: ResumeWalker reindeer" --once
