Visualizing Node Mobility¶
Goals¶
In wireless simulations, the movement of mobile nodes can be a crucial aspect that greatly impacts communication among them. However, visually tracking the movement can be challenging. INET provides a mobility visualizer that makes it easier to follow mobile nodes and displays properties such as speed and direction.
This showcase demonstrates the capabilities of the mobility visualizer.
4.0About the Visualizer¶
In INET, the mobility of nodes can be visualized by MobilityVisualizer
module (included in the network as part of IntegratedVisualizer). By
default, mobility visualization is enabled; it can be disabled by
setting displayMovements parameter to false.
By default, all mobilities are considered for the visualization. This
selection can be narrowed with the visualizer’s moduleFilter
parameter.
The visualizer has several important features:
Movement Trail: It displays a line along the recent path of movements. The trail gradually fades out as time passes. Color, trail length and other graphical properties can be changed with parameters of the visualizer.
Velocity Vector: Velocity is represented visually by an arrow. Its starting point is the node, and its direction coincides with the movement’s direction. The arrow’s length is proportional to the node’s speed.
Orientation Arc: Node orientation is represented by an arc whose size is specified by the
orientationArcSizeparameter. This value is the relative size of the arc compared to a full circle. The arc’s default value is 0.25, i.e. a quarter of a circle.
These features are disabled by default; they can be enabled by setting
the visualizer’s displayMovementTrails, displayVelocities and
displayOrientations parameters to true.
Visualizing Mobility Features¶
The following example shows how to enable mobility visualization
features. The simulation can be run by choosing the
VisualizingFeatures configuration from the ini file.
Three nodes of the type AdhocHost, host1, host2, and
host3, are placed in the scene. They are roaming within
predefined borders.
The following video has been captured from the simulation. The default settings of mobility visualization are used.
It is difficult to track the nodes because they are moving randomly and quite fast. In our next experiment, we enable movement trails, velocity vectors, and orientation arcs. We expect that nodes can be tracked easier.
# Movement trail settings
*.visualizer.*.mobilityVisualizer.displayMovementTrails = true
*.visualizer.*.mobilityVisualizer.trailLength = 300
# Velocity vector settings
*.visualizer.*.mobilityVisualizer.displayVelocities = true
# Orientation settings
*.visualizer.*.mobilityVisualizer.displayOrientations = true
The following video shows what happens when we run the simulation.
Compare this video to the previous one! The first thing you may notice
is that the hosts’ movement is the same as in the previous video.
However, it is now possible to see that the movement of host3 is not
actually random, but rather, it moves along a circle. The host1 and
host2 nodes can also be easily tracked because of the visualization.
Sources: omnetpp.ini, MobilityVisualizerShowcase.ned
More Information¶
This example only demonstrates the key features of mobility visualization. For more information, refer to the MobilityVisualizer NED documentation.