Artificial Lights in Cosys-AirSim

Cosys-AirSim supports adding artificial lights that are either static in the world or attached to the vehicle. These can be configured via the settings.json file.

Vehicle Lights

If lights should move with the vehicle, they can be attached to it. Multiple lights can be enabled on a vehicle. This is done in the Lights section of the Vehicles section in the settings file, each light has a unique name.

  ...
  "Vehicles": {
        "airsimvehicle": {
            ... 
            "Lights": {
                "vehiclelight1": {
                    "X": 0,
                    "Y": 0,
                    "Z": -1,
                    "Roll": 0,
                    "Pitch": 90,
                    "Yaw": 0,
                    "Type": 0,
                    "Temperature": 2500,
                    ...
                },
                "vehiclelight2": {
                    ...
                },
                ...
            },
            ...
        }
  ...
  },
  ...

World Lights

If lights should be static in the world, they should be defined as a world light. This is done in the WorldLights section in the settings file, each world light has a unique name.

...
    "WorldLights": {
        "worldlight1": {
            "X": 10,
            "Y": 10,
            "Z": -5,                    
            "Type": 0,
            "Temperature": 2500,
            "IntensityUnit": 2,
            "Intensity": 8,
            "ColorR": 255,
            "ColorG": 128,
            "ColorB": 255,
            ...
        },
        "worldlight2": {
          ...
        },
        ...
    }

General Light Settings

A light can be configured with several parameters. There are three types of light: spot, point andd rectangular area lights. These correspond to the Unreal light types available. Please see the Unreal documentation for more information on these light types and when to use which.

The following parameters can be configured:

Parameter	Description
X Y Z	Position of the light relative to the vehicle/world (in NED coordinate system, in meters).
Roll Pitch Yaw	Orientation of the light relative to the vehicle/world (in degrees, yaw-pitch-roll order relative to the front vector +X).
Enable	Boolean flag indicating whether the light is enabled by default.
Type	Specifies the type of light: 0 = Spot light (default), 1 = Point light, 2 = Rectangular area light
IntensityUnit	Defines the unit used for light intensity: , 0 = Candelas (default), 1 = Lumens, 2 = EV (Exposure Value, not supported on UE5.2!)
Intensity	Specifies the brightness of the light, expressed in the selected IntensityUnit. Default is 8.
AttenuationRadius	Defines the distance over which the light gradually fades out, measured in cm. Default is 1000.
InnerConeAngle	Applicable only for spotlights; specifies the inner angle of the spotlight’s cone (in degrees). Default is 0.
OuterConeAngle	Applicable only for spotlights; specifies the outer angle of the spotlight’s cone (in degrees). Default is 44.
SourceRadius	Applicable only for spotlights and point lights; specifies the radius of the light source in cm.
SourceSoftRadius	Applicable only for spotlights and point lights; defines the soft edge radius of the light source in meters.
SourceWidth	Applicable only for rectangular lights; specifies the width of the rectangular light source in cm. Default is 64.
SourceHeight	Applicable only for rectangular lights; specifies the height of the rectangular light source in cm. Default is 64.
BarnDoorAngle	Applicable only for rectangular lights; defines the angle of the barn door (in degrees). Default is 88.
BarnDoorLength	Applicable only for rectangular lights; specifies the length of the barn door in meters.
Temperature	Color temperature of the light in Kelvin. Defaults to 6500 (standard daylight white light).
CastShadows	Boolean flag indicating whether the light casts shadows.
ColorR	Red component of the light color (0-255). Default color is white.
ColorG	Green component of the light color (0-255). Default color is white.
ColorB	Blue component of the light color (0-255). Default color is white.

Client API

You can toggle lights on and off with the API as well as set their intensity value. There are seperate commands for vehicle and world lights:

• simSetWorldLightVisibility(light_name (string), is_visible (boolean))
• simSetWorldLightIntensity(light_name (string), intensity (float))
• simSetVehicleLightVisibility(vehicle_name (string), light_name (string), is_visible (boolean))
• simSetVehicleLightIntensity(vehicle_name (string), light_name (string), intensity (float))