Implementation:CARLA simulator Carla LightManager Class

Knowledge Sources	CARLA
Domains	Client Library, Lighting, Scene Management
Last Updated	2026-02-15 05:00 GMT

Overview

LightManager is the client-side class for querying and controlling all lights in a CARLA simulation scene, supporting bulk operations on light groups with color, intensity, and state management.

Description

The LightManager class in the carla::client namespace extends EnableSharedFromThis<LightManager> and provides comprehensive light control. It is non-copyable by design via carla::NonCopyable (though a copy constructor is explicitly defined for internal use).

Light Group Type

Uses rpc::LightState::LightGroup as the LightGroup type alias for categorizing lights (e.g., Street, Building, Vehicle, None).

Bulk Operations (vector-based)

Each operation works on a std::vector<Light>:

• TurnOn / TurnOff -- Toggle lights on/off.
• SetActive / IsActive -- Set or query active state with paired boolean vectors.
• GetTurnedOnLights / GetTurnedOffLights -- Query lights by on/off state, optionally filtered by LightGroup.
• SetColor / GetColor -- Uniform or per-light color setting/querying.
• SetIntensity / GetIntensity -- Uniform or per-light intensity setting/querying.
• SetLightGroup / GetLightGroup -- Uniform or per-light group assignment/querying.
• SetLightState / GetLightState -- Uniform or per-light LightState setting/querying.

Individual Operations (by LightId)

Per-light operations indexed by LightId:

• GetColor(id), GetIntensity(id), GetLightState(id), GetLightGroup(id), IsActive(id)
• SetActive(id, active), SetColor(id, color), SetIntensity(id, intensity), SetLightState(id, state), SetLightStateNoLock(id, state), SetLightGroup(id, group)

Day/Night Cycle

• SetDayNightCycle(active) -- Enables or disables the automatic day/night cycle.

Internal State Management

• _lights_state -- Map of current light states keyed by LightId.
• _lights_changes -- Map of pending light state changes.
• _lights -- Map of Light objects.
• _episode -- WeakEpisodeProxy for simulator communication.
• _mutex -- Thread safety for concurrent access.
• _on_tick_register_id / _on_light_update_register_id -- Event registration IDs.
• _dirty -- Flag indicating pending changes.

Private methods QueryLightsStateToServer, UpdateServerLightsState, and ApplyChanges handle server synchronization.

Usage

Obtain the LightManager from the world and use it to control scene lighting for day/night scenarios, specific lighting conditions, or visual debugging.

Code Reference

Source Location

• Repository: CARLA
• File: LibCarla/source/carla/client/LightManager.h (113 lines)

Signature

namespace carla {
namespace client {

class LightManager : public EnableSharedFromThis<LightManager> {
  using LightGroup = rpc::LightState::LightGroup;

public:
  LightManager();
  ~LightManager();

  void SetEpisode(detail::WeakEpisodeProxy episode);
  std::vector<Light> GetAllLights(LightGroup type = LightGroup::None) const;

  void TurnOn(std::vector<Light>& lights);
  void TurnOff(std::vector<Light>& lights);
  void SetActive(std::vector<Light>& lights, std::vector<bool>& active);
  std::vector<bool> IsActive(std::vector<Light>& lights) const;

  void SetColor(std::vector<Light>& lights, Color color);
  void SetColor(std::vector<Light>& lights, std::vector<Color>& colors);
  std::vector<Color> GetColor(std::vector<Light>& lights) const;

  void SetIntensity(std::vector<Light>& lights, float intensity);
  void SetIntensity(std::vector<Light>& lights, std::vector<float>& intensities);
  std::vector<float> GetIntensity(std::vector<Light>& lights) const;

  void SetLightState(std::vector<Light>& lights, LightState state);
  void SetLightState(std::vector<Light>& lights, std::vector<LightState>& states);
  std::vector<LightState> GetLightState(std::vector<Light>& lights) const;

  void SetDayNightCycle(const bool active);

  // Per-ID accessors
  Color GetColor(LightId id) const;
  float GetIntensity(LightId id) const;
  LightState GetLightState(LightId id) const;
  void SetLightState(LightId id, const LightState& new_state);
  // ... additional per-ID methods
};

} // namespace client
} // namespace carla

Import

#include "carla/client/LightManager.h"

I/O Contract

Inputs

Name	Type	Required	Description
episode	detail::WeakEpisodeProxy	Yes	Weak episode proxy for server communication
lights	std::vector<Light>	Yes (for bulk ops)	List of lights to operate on
color	Color	No	Color to set on lights
intensity	float	No	Intensity to set on lights
state	LightState	No	Complete light state to apply
type	LightGroup	No	Light group filter (default: None = all)

Outputs

Name	Type	Description
all_lights	std::vector<Light>	All lights matching the group filter
colors	std::vector<Color>	Queried colors for specified lights
intensities	std::vector<float>	Queried intensities for specified lights
states	std::vector<LightState>	Queried light states for specified lights
active	std::vector<bool>	Active state for specified lights

Usage Examples

auto light_manager = world.GetLightManager();

// Get all street lights
auto street_lights = light_manager->GetAllLights(
    carla::rpc::LightState::LightGroup::Street);

// Turn on all street lights
light_manager->TurnOn(street_lights);

// Set warm color
light_manager->SetColor(street_lights, carla::sensor::data::Color{255, 200, 150});

// Disable day/night cycle for manual control
light_manager->SetDayNightCycle(false);

Related Pages

• Environment:CARLA_simulator_Carla_Simulation_Runtime
• CARLA_simulator_Carla_Python_LightManager_Bindings - Python bindings for this class