This page explains how to create a simple `vehicle.lua` file, primarily intended for AI-controlled trains in SubwaySim 2.

A simple `vehicle.lua` usually defines:

• Vehicle metadata (name, author, IDs)
• Basic physical parameters (mass, length, vmax)
• Blueprint references
• Coupling definitions
• Braking systems
• Basic lights and audio
• Train compositions for AI

For a detailed explanation of a fully featured and player-drivable vehicle, see:

• Complex Vehicle.lua

The following example is based on the GI1E (Gisela) AI vehicle used in the SubwaySim base game.

Because the original file is not publicly downloadable, the full structure is shown below and explained step by step in separate sections.

vehicle.lua

---@type RailVehicle_DataTable
local GI1E_a = {
	contentType		= "railVehicle",
	contentName		= "Berlin_GI1E_a",
 
	title			= "GI1E",
	author			= "$GameDeveloper",
 
	emptyMass			= 37.0,
	vmax				= 70,
 
	length				= 12.64,
	frontToFirstBogie	= 2.53,
	rearToLastBogie		= 2.53,
 
	maxEnginePower		= 480,
	maxEngineForce		= 50,
 
	blueprintFilename	= "/SubwaySim_Berlin/Vehicles/GI1E/BP_GI1E_A.BP_GI1E_A",
 
	couplingFront		= {
		rotationOrigin		= "Coupling_F",
		couplingOffset		= 0.985,
		automaticCoupling	= true,
		skeletalMesh		= "Exterior",
		couplingBoneName	= "Coupling_Rotation1",
	},
	couplingRear		= {
		rotationOrigin		= "Coupling_B",
		couplingOffset		= 0.985,
		automaticCoupling	= true,
		skeletalMesh		= "Exterior",
		couplingBoneName	= "Coupling_Rotation2",
	},
 
	-- players shouldn't try to attach this vehicle
	cameras				= {
		exteriorCameras	= {},
	},
 
	brakingSystems		= {
		pneumatic5bar	= {
			maxBrakeForce	= 60,
		},
		electric		= {
			maxBrakeForce	= 50,
			maxBrakePower	= 480,
		},
	},
 
	components = {
		LightManager,
		VehicleNumber,
		AudioManager,
		Berlin_PIS,
	},
 
	audio = {
		audioBogieAI = {
			{
				audioComponent = "AiAudio",
			},
		},
	},
 
	lights = {
		headLights = {
			{
				direction			= 1,
				headlightElements	= {
					{
						mesh			= "Exterior",
						materialSlot	= "GI1E_LightsExterior_mat",
						materialParams	= {
							["Emissive01"] = 100,
						},
						lightComponents	= {
							{lightComponent ="Headlight1", intensity = 50, temperature = 4500, attenuationRadius = 500, innerConeAngle = 0, outerConeAngle = 70},
							{lightComponent ="Headlight2", intensity = 50, temperature = 4500, attenuationRadius = 500, innerConeAngle = 0, outerConeAngle = 70},
						},
					},
				},
			},
		},
		tailLights = {
			{
				mesh			= "Exterior",
				materialSlot	= "GI1E_LightsExterior_mat",
				direction		= -1,
				materialParams	= {
					["Emissive02"] = 100,
				},
			},
		},
	},
 
	---@type Berlin_PIS_DataTable
	PIS = {
		destinationDisplays	= {
			{
				componentName	= "ZZA",
				direction		= 1,
			},
		},
 
		announcementNextStop		= {},
		announcementTerminus		= {
			"/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/General_Termination01.General_Termination01",
		},
		announcementExitLeft		= {},
		announcementExitRight		= {
			"/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/General_ExitRight.General_ExitRight",
		},
		announcementBell			= {
			"/SubwaySim_Berlin/Vehicles/Shared/Audio/Gong/Berlin_Standardgong_MasterV1_kurz.Berlin_Standardgong_MasterV1_kurz",
		},
		announcementTerminusBell	= {
			"/SubwaySim_Berlin/Vehicles/Shared/Audio/Gong/Berlin_Infogong_MasterV2_kurz.Berlin_Infogong_MasterV2_kurz",
		},
		announcementDelay					= 1.2,
		defaultDestinationAnnouncement		= "/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/Destination_General.Destination_General",
		destinationAnnouncementByLine		= {
			["U1"]	= "/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/Destination_U1.Destination_U1",
			["U2"]	= "/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/Destination_U2.Destination_U2",
			["U3"]	= "/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/Destination_U3.Destination_U3",
			["U4"]	= "/SubwaySim_Berlin/Vehicles/Shared/Audio/Announcements/Destination_U4.Destination_U4",
		},
 
		audioComponent				= "PIS_Audio",
		autoTerminateAnnouncement	= false,
	},
 
	vehicleNumber = {
		labels	= {
			{
				mesh			= "Exterior",
				materialSlot	= "DecalDigits_mat",
			},
		},
		poolName		= "Berlin_GI1E",
		poolValueMin	= 1070,
		poolValueMax	= 1094,
	},
};
 
---@type RailVehicle_DataTable
local GI1E_b 								= TableUtil.deepCopy(GI1E_a);
GI1E_b.components 							= GI1E_a.components; -- TODO
GI1E_b.contentName 							= "Berlin_GI1E_b";
GI1E_b.blueprintFilename 					= "/SubwaySim_Berlin/Vehicles/GI1E/BP_GI1E_B.BP_GI1E_B";
GI1E_b.lights.headLights					= nil;
GI1E_b.lights.tailLights					= nil;
GI1E_b.couplingFront.couplingBoneName		= "Coupling_Rotation3";
GI1E_b.couplingRear.couplingBoneName		= "Coupling_Rotation4";
 
---@type TrainComposition_DataTable
local GI1E_1x = {
	contentType		= "trainComposition",
	contentName		= "Berlin_GI1e_1x",
 
	title			= "GI1e x1",
	author			= "Simuverse GmbH",
 
	-- not required for AI trains
	description			= "",
	previewFilename 	= "",
	hidden 				= true,
 
	vehicles		= {
		{
			contentName	= "Berlin_GI1E_a",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= false,
		},
		{
			contentName	= "Berlin_GI1E_a",
			forward		= false,
		},
	},
};
 
---@type TrainComposition_DataTable
local GI1E_2x = {
	contentType		= "trainComposition",
	contentName		= "Berlin_GI1e_2x",
 
	title			= "GI1e x2",
	author			= "Simuverse GmbH",
 
	-- not required for AI trains
	description			= "",
	previewFilename 	= "",
	hidden 				= true,
 
	vehicles		= {
		{
			contentName	= "Berlin_GI1E_a",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= false,
		},
		{
			contentName	= "Berlin_GI1E_a",
			forward		= false,
		},
		{
			contentName	= "Berlin_GI1E_a",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= true,
		},
		{
			contentName	= "Berlin_GI1E_b",
			forward		= false,
		},
		{
			contentName	= "Berlin_GI1E_a",
			forward		= false,
		},
	},
};
 
g_contentManager:addContent(GI1E_a);
g_contentManager:addContent(GI1E_b);
g_contentManager:addContent(GI1E_1x);
g_contentManager:addContent(GI1E_2x);

Now we will go through the `RailVehicle_DataTable` step by step.

The `RailVehicle_DataTable` contains the core configuration of a vehicle. It defines all information required so the game can correctly:

• load the vehicle Blueprint,
• place the vehicle on the track,
• apply physics and braking,
• configure couplings,
• and register audio, lights, and additional Lua components.

In this example, the DataTable is stored in a local Lua table called `GI1E_a`.

---@type RailVehicle_DataTable
local GI1E_a = {

These fields define what the vehicle is and how it appears inside the content system.

These values define physical base properties and basic performance.

These values are critical for correct placement on the track and correct bogie positioning.

These values define the maximum propulsion capability of the vehicle.

This defines which Unreal Blueprint is loaded for this vehicle.

This section is crucial for:

• correct vehicle placement on the rail,
• correct coupling rotation,
• automatic coupling behavior in consists.

The front coupling:

couplingFront = {
    rotationOrigin     = "Coupling_F",
    couplingOffset     = 0.985,
    automaticCoupling  = true,
    skeletalMesh       = "Exterior",
    couplingBoneName   = "Coupling_Rotation1",
},

The rear coupling works the same way:

couplingRear = {
    rotationOrigin     = "Coupling_B",
    couplingOffset     = 0.985,
    automaticCoupling  = true,
    skeletalMesh       = "Exterior",
    couplingBoneName   = "Coupling_Rotation2",
},

Defines exterior cameras if the vehicle supports them. For AI vehicles, this is typically empty.

cameras = {
    exteriorCameras = {},
},

Defines available brake systems and their maximum forces.

brakingSystems = {
    pneumatic5bar = {
        maxBrakeForce = 60,
    },
    electric = {
        maxBrakeForce = 50,
        maxBrakePower = 480,
    },
},

This list defines which Lua components are attached to the vehicle.

components = {
    LightManager,
    VehicleNumber,
    AudioManager,
    Berlin_PIS,
},

Defines which Blueprint Audio Component is used for AI bogie sound playback.

audio = {
    audioBogieAI = {
        {
            audioComponent = "AiAudio",
        },
    },
},

This section defines headlights and taillights, including:

• which direction they apply to,
• which mesh + material slot is affected,
• which emissive parameters are set,
• and which Light Components are controlled.

Headlights example:

headLights = {
    {
        direction = 1,
        headlightElements = {
            {
                mesh = "Exterior",
                materialSlot = "GI1E_LightsExterior_mat",
                materialParams = {
                    ["Emissive01"] = 100,
                },
                lightComponents = {
                    {lightComponent ="Headlight1", intensity = 50, temperature = 4500, attenuationRadius = 500, innerConeAngle = 0, outerConeAngle = 70},
                    {lightComponent ="Headlight2", intensity = 50, temperature = 4500, attenuationRadius = 500, innerConeAngle = 0, outerConeAngle = 70},
                },
            },
        },
    },
},

Taillights example:

tailLights = {
    {
        mesh = "Exterior",
        materialSlot = "GI1E_LightsExterior_mat",
        direction = -1,
        materialParams = {
            ["Emissive02"] = 100,
        },
    },
},

The PIS section defines:

• which destination display components exist,
• which announcement audio files are used,
• the audio component for playback,
• and additional announcement logic settings.

Key elements:

• `destinationDisplays` defines display components (e.g. `ZZA`)
• audio lists define announcement file assets
• `audioComponent` defines the Blueprint Audio Component used for announcements

(Your provided PIS block remains valid and can be explained further in the next section.)

Defines how vehicle numbers are generated and displayed.

vehicleNumber = {
    labels = {
        {
            mesh = "Exterior",
            materialSlot = "DecalDigits_mat",
        },
    },
    poolName     = "Berlin_GI1E",
    poolValueMin = 1070,
    poolValueMax = 1094,
},

(Continuation follows: copying variants with `deepCopy`, defining TrainCompositions, and registering content via `g_contentManager:addContent()`.)