The event trigger in the scene with 2D physics support.
For a good overview of sensors, you can take a look at the 'Sensors 2D.scene' file, which can be found in 'Assets\Samples\Starter Content\Scenes'.
The sensor allows you to select scene objects by a given volume or ray.
The parameter 'Source Data' indicates what type of objects will be determined: scene objects or physical bodies.
In order to see which objects the sensor has selected, you need to enable the 'Display Objects' parameter.
|Source Data||What kind of data is used as a source of events.|
|Shape||The shape of the trigger.|
|Ray Target||The target by which the sensor ray will trigger.|
|Mode||The recognition mode of the sensor.|
|Filter By Type||The type of objects that sensor will recognize.|
|Collision Categories||The collision categories this fixture is a part of.|
|Collides With||The collision mask bits. This states the categories that this fixture would accept for collision.|
|Collision Group||Collision groups allow a certain group of objects to never collide or always collide. Zero means no collision group. Non-zero group filtering always wins against the mask bits.|
|Ignore Sensors||Whether the sensor is ignoring other sensors.|
|When Update||The update case mode of the sensor.|
|Display Color||The display color of the sensor.|
|Display Objects||Whether to draw gizmos on the objects recognized by the sensor.|
|Display Objects Color||The color of the recognized object gizmos.|
|Objects||List of objects recognized by the sensor.|