Flow Mission

Reference for the flowgraph mission type, the primary mission class used by most BeamNG missions. Extends `baseMission` with flowgraph manager integration, vehicle/traffic/environment setup modules, c

Reference for the flowgraph mission type, the primary mission class used by most BeamNG missions. Extends baseMission with flowgraph manager integration, vehicle/traffic/environment setup modules, career star/reward support, and custom script loading.

Module Export

Returns a constructor function (derivedClass, ...) that creates a flowMission instance inheriting from baseMission's C class. Accessible via gameplay_missions_missions.flowMission().

Class C - Key Methods

Lifecycle

Method	Signature	Description
`onStart`	`C:onStart()`	Loads FG manager, sets variables, starts flowgraph, calls custom script
`onUpdate`	`C:onUpdate(dtReal, dtSim, dtRaw)`	Calls script `onUpdate`, applies wind to vehicles
`onStop`	`C:onStop(data)`	Stops FG manager, aggregates abandoned attempt, calls script `onStop`
`attemptAbandonMission`	`C:attemptAbandonMission()` → bool	Delegates to FG's `onRequestAbandon` hook if available

Setup & Configuration

Method	Signature	Description
`getCommonSettingsData`	`C:getCommonSettingsData()` → table	Builds vehicle/traffic/environment user settings UI data
`processCommonSettings`	`C:processCommonSettings(flatSettings)`	Applies user settings to setup modules
`processUserSettings`	`C:processUserSettings(settings)`	Stores user settings for later use
`setBackwardsCompatibility`	`C:setBackwardsCompatibility(keyAliases)`	Migrates old mission formats (vehicle modes, timeOfDay)
`setPreviewsForCustomVehicles`	`C:setPreviewsForCustomVehicles(userSettings)`	Updates thumbnails for custom vehicle selections

Flowgraph Integration

Method	Signature	Description
`setupFlowgraphManager`	`C:setupFlowgraphManager(fgFile, variables)`	Loads FG project, sets mission/progress variables
`addOrSetVariable`	`C:addOrSetVariable(name, value)` → err	Sets a flowgraph variable (bool/string/number/vec3/quat)
`retrieveProgressFromFlowgraph`	`C:retrieveProgressFromFlowgraph()`	Reads progress variables back from FG

Career

Method	Signature	Description
`getEntryFee`	`C:getEntryFee(userSettings)` → table\|nil	Returns entry fee (attribute amounts)
`getDynamicStarReward`	`C:getDynamicStarReward(key, userSettings)`	Override point for dynamic star rewards
`getGameContextUiButtons`	`C:getGameContextUiButtons()` → table	Gathers UI buttons from FG nodes
`getRules`	`C:getRules()` → table	Loads HTML rule pages from mission layers
`showRulesAsPopups`	`C:showRulesAsPopups()`	Displays rules as intro popups

Setup Modules

Missions configure these via setupModules:

Vehicles

enabled - whether vehicle setup is active
vehicles - array of {model, config, configPath, paintName}
includePlayerVehicle - allow player's own car
prioritizePlayerVehicle - default to player's car
User setting key: setupModuleVehicles

Traffic

enabled, useTraffic, usePrevTraffic, useSimpleVehs, useGameOptions
amount, activeAmount, parkedAmount, respawnRate
customGroupFile - vehicle group JSON
User setting key: setupModuleTraffic

Environment

enabled, time, timeScale, fogDensity, windSpeed, windDirAngle
todUserSetting - enable time-of-day user setting
User setting key: setupModuleEnvironmentTime

How It Works

-- Mission start flow:
function C:onStart()
  -- 1. Log issues for debugging
  -- 2. Call onPreStart() if defined
  -- 3. Merge fgVariables + oneOffVariables
  -- 4. Call preprocessMissionTypeData() if defined
  -- 5. setupFlowgraphManager(fgPath, variables)
  -- 6. Set progress variables from saved progress
  -- 7. Set user settings as FG variables
  -- 8. Start FG manager
  -- 9. Call script:onStart() if loaded
end

Key Behaviors

Custom scripts loaded from missionFolder/script.lua - instantiated with {mission = mission}
FG variables only set if they already exist in the flowgraph (no auto-creation)
ignoreUserSettingsKeyForActiveStars excludes certain settings from star eligibility checks
Backwards compatibility handles old mode vehicle setup, timeOfDay number format, and old branch names
onFlowgraphStateStarted/Stopped hooks forwarded to custom scripts
Vehicle hooks (onVehicleReset) forwarded via scriptHooks table

Method	Signature	Description
`onStart`	`C:onStart()`	Loads FG manager, sets variables, starts flowgraph, calls custom script
`onUpdate`	`C:onUpdate(dtReal, dtSim, dtRaw)`	Calls script `onUpdate`, applies wind to vehicles
`onStop`	`C:onStop(data)`	Stops FG manager, aggregates abandoned attempt, calls script `onStop`
`attemptAbandonMission`	`C:attemptAbandonMission()` → bool	Delegates to FG's `onRequestAbandon` hook if available

Setup & Configuration

Method	Signature	Description
`getCommonSettingsData`	`C:getCommonSettingsData()` → table	Builds vehicle/traffic/environment user settings UI data
`processCommonSettings`	`C:processCommonSettings(flatSettings)`	Applies user settings to setup modules
`processUserSettings`	`C:processUserSettings(settings)`	Stores user settings for later use
`setBackwardsCompatibility`	`C:setBackwardsCompatibility(keyAliases)`	Migrates old mission formats (vehicle modes, timeOfDay)
`setPreviewsForCustomVehicles`	`C:setPreviewsForCustomVehicles(userSettings)`	Updates thumbnails for custom vehicle selections

Flowgraph Integration

Method	Signature	Description
`setupFlowgraphManager`	`C:setupFlowgraphManager(fgFile, variables)`	Loads FG project, sets mission/progress variables
`addOrSetVariable`	`C:addOrSetVariable(name, value)` → err	Sets a flowgraph variable (bool/string/number/vec3/quat)
`retrieveProgressFromFlowgraph`	`C:retrieveProgressFromFlowgraph()`	Reads progress variables back from FG

Career

Method	Signature	Description
`getEntryFee`	`C:getEntryFee(userSettings)` → table\|nil	Returns entry fee (attribute amounts)
`getDynamicStarReward`	`C:getDynamicStarReward(key, userSettings)`	Override point for dynamic star rewards
`getGameContextUiButtons`	`C:getGameContextUiButtons()` → table	Gathers UI buttons from FG nodes
`getRules`	`C:getRules()` → table	Loads HTML rule pages from mission layers
`showRulesAsPopups`	`C:showRulesAsPopups()`	Displays rules as intro popups

Setup Modules

Missions configure these via setupModules:

Vehicles

enabled - whether vehicle setup is active
vehicles - array of {model, config, configPath, paintName}
includePlayerVehicle - allow player's own car
prioritizePlayerVehicle - default to player's car
User setting key: setupModuleVehicles

Traffic

enabled, useTraffic, usePrevTraffic, useSimpleVehs, useGameOptions
amount, activeAmount, parkedAmount, respawnRate
customGroupFile - vehicle group JSON
User setting key: setupModuleTraffic

Environment

enabled, time, timeScale, fogDensity, windSpeed, windDirAngle
todUserSetting - enable time-of-day user setting
User setting key: setupModuleEnvironmentTime

How It Works

-- Mission start flow:
function C:onStart()
  -- 1. Log issues for debugging
  -- 2. Call onPreStart() if defined
  -- 3. Merge fgVariables + oneOffVariables
  -- 4. Call preprocessMissionTypeData() if defined
  -- 5. setupFlowgraphManager(fgPath, variables)
  -- 6. Set progress variables from saved progress
  -- 7. Set user settings as FG variables
  -- 8. Start FG manager
  -- 9. Call script:onStart() if loaded
end

Key Behaviors

Custom scripts loaded from missionFolder/script.lua - instantiated with {mission = mission}
FG variables only set if they already exist in the flowgraph (no auto-creation)
ignoreUserSettingsKeyForActiveStars excludes certain settings from star eligibility checks
Backwards compatibility handles old mode vehicle setup, timeOfDay number format, and old branch names
onFlowgraphStateStarted/Stopped hooks forwarded to custom scripts
Vehicle hooks (onVehicleReset) forwarded via scriptHooks table

Flow Mission

Module Export

Class C - Key Methods

Lifecycle

Setup & Configuration

Flowgraph Integration

Career

Setup Modules

Vehicles

Traffic

Environment

How It Works

Key Behaviors

See Also

On this page

Flow Mission

Module Export

Class C - Key Methods

Lifecycle

Setup & Configuration

Flowgraph Integration

Career

Setup Modules

Vehicles

Traffic

Environment

How It Works

Key Behaviors

See Also

On this page