func_tracktrain
Not to be confused with func_tanktrain.
func_tracktrain
is a brush entity available in all Source games. It functions as a moving platform that the player can ride. It follows a path of
path_track
entities.

Fixed Orientation
flag is set, build your train so that the front of the train is facing down the X axis. (This means that the front of the train is visible in the front view, etc.) When it spawns it will automatically rotate to face the next path_track
on the path.
func_train
entity is not affected by this issue, so it may be a suitable alternative for high-speed objects.
Reverse
and StartBackward
may not function correctly if the New Train Speed
property in the involved path_track
entities is set to 0. The train may fail to reverse, jamming in place or moving in the wrong direction. To solve this issue, some or all of the path_tracks
must have their New Train Speed
variable set to a non-zero value.


CFuncTrackTrain
class, defined in thetrains.cpp
file.Contents
Keyvalues
BaseTrain:
- First Stop Target
(target)
<targetname> - The name of the first
path_track
in the train's path. The train will spawn at thispath_track
. It will also turn to face the direction indicated by the "Orientation Type" setting.
- Max Speed (units/second)
(startspeed)
<integer> - The maximum speed that this train can move. Any speeds applied to this train, such as by
path_track
s orSetSpeed
inputs, will be clipped to this maximum value.
- Initial Speed (units/second)
(speed)
<integer> - The speed that the train will move at after it spawns, 0 = stopped.
- Change Velocity
(velocitytype)
<choices> - The method through which this train changes its velocity as it moves along the path.
- 0 : Instantaneously
- 1 : Linear blend
- 2 : Ease in/ease out
- Change angles
(orientationtype)
<choices> - The method through which this train changes its orientation as it moves along the path.
- 0 : Never (always fixed orientation)
- 1 : Near paths
- 2 : Linear blend
- 3 : Ease in/ease out
- Distance Between the Wheels
(wheels)
<integer> - Used for turning and stopping.
Tip:Increase the value for smoother turns.
- Height above track
(height)
<integer> - The height above the track that this train moves.
- Bank Angle on Turns
(bank)
<string> - The angle at which the train will "bank" or tilt when approaching a turn. Use positive or negative angle numbers close to 0 (i.e., between -5 and +5, depending on left or right) to achieve realistic tilt angles.
- Damage on Crush
(dmg)
<integer> - The amount of damage this train does to entities that block it.
- Minimum Light Level
(_minlight)
<string> - The minimum level of ambient light that hits this brush.
- Move Sound
(MoveSound)
<sound> - A sound that is played (and looped) while the train is moving.
- Move Ping Sound
(MovePingSound)
<sound> - A sound that is played more frequently as the train speeds up.
- Start Sound
(StartSound)
<sound> - A sound played when the train starts moving.
- Stop Sound
(StopSound)
<sound> - A sound played when the train stops moving.
- Volume (10 = loudest)
(volume)
<integer> - Volume of the sound when the train is moving.
- Min pitch (1-255, 100 = normal)
(MoveSoundMinPitch)
<integer> - The sound pitch value that the train will approach as it comes to a stop.
- Max pitch (1-255, 100 = normal)
(MoveSoundMaxPitch)
<integer> - The sound pitch value that the train will approach as it approaches its max speed (or 1000 inches/second if the "Use max speed for pitch shifting move sound" flag is not set).
- Min move sound interval
(MoveSoundMinTime)
<float> - Minimum interval at which to play the move ping sound.
- Max move sound interval
(MoveSoundMaxTime)
<float> - Maximum interval at which to play the move ping sound.
- Manual Train Speed
(manualspeedchanges)
<boolean> - Train Speed is controlled through IO, handles accel, decel times.
- Manual Accel Speed
(manualaccelspeed)
<float> - Units per second to accelerate to target speed.
- Manual Decel Speed
(manualdecelspeed)
<float> - Units per second to decelerate to target speed.

Base:
- Collisions
(solid)
<choices> - Method of collision for this entity.
- 0: None
- 1: BSP (QPhysics) !FGD
Bug:In
, if an entity using QPhysics collisions is hit by Gel, the game will crash!
- 2: Bounding Box
- 3: Oriented Bounding Box (Use for runtime spawned brush entities meant to be rotated) !FGD
- 4: Oriented Bounding Box but constrained to Yaw only !FGD
- 5: Custom/Test (Usually no collision with anything) !FGD
- 6: VPhysics
- Parent
(parentname)
<targetname> - Maintain the same initial offset to this entity. An attachment point can also be used if separated by a comma at the end. (
parentname [targetname],[attachment]
)Tip:Entities transition to the next map with their parents
Tip:
phys_constraint
can be used as a workaround if parenting fails.
- Origin (X Y Z)
(origin)
<coordinates> - The position of this entity's center in the world. Rotating entities typically rotate around their origin.
Note:Hammer does not move the entities accordingly only in the editor.
- Pitch Yaw Roll (X Y Z)
(angles)
<angle> - This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.
Note:This works on brush entities, although Hammer doesn't show the new angles.
- Classname
(classname)
<string> !FGD - Determines the characteristics of the entity before it spawns.
Note:Changing this on runtime still has use, like making matching an entry in S_PreserveEnts will persist the entity on new rounds!
- Flags
(spawnflags)
<integer> !FGD - Toggles exclusive features of an entity, its specific number is determined by the combination of flags added.
- Effects
(effects)
<integer> !FGD - Combination of effect flags to use.
- Entity Scripts
(vscripts)
<scriptlist> (in all games since) (also in
)
- Space delimited list of VScript files (without file extension) that are executed after all entities have spawned. The scripts are all executed in the same script scope, later ones overwriting any identical variables and functions. Scripts executed on the worldspawn entity will be placed in root scope.
- Think function
(thinkfunction)
<string> (in all games since) (also in
)
- Name of the function within this entity's script that'll be called automatically every 100 milliseconds, or a user-defined interval if the function returns a number. Avoid expensive operations in this function, as it may cause performance problems.
- Lag Compensation
(LagCompensate)
<boolean> (in all games since) !FGD
- Set to Yes to lag compensate this entity. Should be used very sparingly!
- Is Automatic-Aim Target
(is_autoaim_target)
<boolean> (in all games since) !FGD
- If set to 1, this entity will slow down aiming movement for consoles and joystick controllers when the entity is under the crosshairs.
VisibleBrush:
- Minimum Light
(_minlight)
<float> - Minimum amount of light to hit this brush. 0 is none, 1 is normal, and 2 is doubled.
- Damage Filter Name
(damagefilter)
<targetname> - When this entity receives damage, it will filter by this entity.
- Render Mode
(rendermode)
<choices> - Set a non-standard rendering mode on this entity.
- Render FX
(renderfx)
<choices> - Various somewhat legacy alpha effects.


- 0: None
- 1: Slow Pulse (varies alpha by ±16 over a period of 1.5 s)
- 2: Fast Pulse (varies alpha by ±16 over a period of 0.4 s)
- 3: Slow Wide Pulse (varies alpha by ±64 over a period of 1.5 s)
- 4: Fast Wide Pulse (varies alpha by ±64 over a period of 0.4 s)
- 5: Slow Fade Away (decreases alpha by -1 per frame/(in all games since
) Fades out over 4 s)
- 6: Fast Fade Away (decreases alpha by -4 per frame/(in all games since
) Fades out over 1 s)
- 7: Slow Become Solid (increases alpha by +1 per frame/(in all games since
) Fades in over 4 s)
- 8: Fast Become Solid (increases alpha by +4 per frame/(in all games since
) Fades in over 1 s)
- 9: Slow Strobe (transparent 0.8 s, visible 0.8 s, repeat)
- 10: Fast Strobe (transparent 0.2 s, visible 0.2 s, repeat)
- 11: Faster Strobe (transparent 0.09 s, visible 0.09 s, repeat)
- 12: Slow Flicker (transparent 0.18 s, visible 1.5 s, repeat)
- 13: Fast Flicker (transparent 0.14 s, visible 0.2 s, repeat)
- 14: Constant Glow ("NoDissipation;" purpose uncertain—for sprites?) (not in
)
- 15: Distort (causes unnatural flickering and position shifting)/(in all games since
) Fade Out (instant; not very useful outside of code)
- 16: Hologram (Distort + "distance fade")/(in all games since
) Fade In (instant; not very useful outside of code)
- 17: Scale Up ("Explode"/"scale up really big!" causes wild stretching of model parts) (in
)/Fade Wider Pulse (varies alpha by ±255 over a period over a period of 0.26 s) (in all games since
)
Confirm:which branches/games is it available in, and where does it do what?
- 18: Glow Shell (purpose unclear) (in all games since
) (not in
)
Confirm:what does this do? and which games is it in?
- 19: Clamp Minimum Scale ("keep this sprite from getting very small (SPRITES only!)") (not in
)
- 20: Environmental Rain ("for environmental rendermode, make rain") (in
) (not in
)
Confirm:which games? may be nonfunctional.
- 21: Environmental Snow ("for environmental rendermode, make snow") (in
) (not in
)
Confirm:which games? may be nonfunctional.
- 22: Spotlight FX ("TEST CODE for experimental spotlight") (in
) (not in
)
- 23: Ragdoll ("HACKHACK: TEST CODE for signalling death of a ragdoll character;" ragdolls an entity but doesn't kill it) (in
) (not in
)
Confirm:which games? may be nonfunctional?
- 24: Fade Wider Pulse (varies alpha by ±255 over a period over a period of 0.26 s) (in
) (not in
)
- 25:
kRenderFXMax
/Fade Near (removed since) (not in
)
Todo: what does this do? may be nonfunctional
- Render FX / Transparency (0–255)
(renderamt)
<integer 0–255> - Transparency amount; requires a Render Mode other than Normal. 0 is invisible, 255 is fully visible.
- Render Color (R G B)
(rendercolor)
<color255> - Color tint.
- Shadow Cast Distance
(shadowcastdist)
<integer> !FGD - Sets how far the entity casts dynamic shadows. 0 means default distance from the
shadow_control
entity.
- Shadows
(vrad_brush_cast_shadows)
<integer> !FGD - Determines if this entity will cast lightmap shadows.
- 0: No shadows
- 1: Cast shadows
- Disable Receiving Shadows
(disablereceiveshadows)
<boolean> - Prevent the entity from receiving shadows on itself.
- Texture Frame
(texframeindex)
<integer> !FGD - The frame number for any animated textures on this entity.
DXLevelChoice:
- Minimum DX Level
(mindxlevel)
<choices> (removed since)
- The entity will not exist if the engine is running outside the given range of DirectX Versions.
Warning:If these are used, the object may break when the user switches their DirectX settings.
SystemLevelChoice:
- Maximum Effect Details Level
(maxcpulevel)
<choices> (in all games since)
- Don't render for players with Effect Details levels that exceed the minimum or maximum.
- 0: Default ("Low" for
mincpulevel
, "High" formaxcpulevel
) - 1: Low
- 2: Medium
- 3: High
- 0: Default ("Low" for

cpu_level
command, the command Effect Details uses.- Maximum Shader Details Level
(maxgpulevel)
<choices> (in all games since)
- Don't render for players with Shader Details levels that exceed the minimum or maximum.
- 0: Default ("Low" for
mingpulevel
, "Very High" formaxgpulevel
) - 1: Low
- 2: Medium
- 3: High
- 4: Very High
- 0: Default ("Low" for

gpu_level
command, the command Shader Details uses.Shadow:
- Disable Shadows
(disableshadows)
<boolean> - Prevents the entity from creating cheap render-to-texture shadows, or lightmap shadows if the entity is a
prop_static
. Does not affect shadow mapping. - Disable ShadowDepth
(disableshadowdepth)
<boolean> (in all games since)
- Used to disable rendering into shadow depth (for projected textures) for this entity.
- Projected Texture Cache
(shadowdepthnocache)
<choices> (in all games since)
- Used to hint projected texture system whether it is sufficient to cache shadow volume of this entity or to force render it every frame instead.
- 0 : Default
- 1 : No cache - render every frame
- 2 : Cache it - render only once
- Disable flashlight
(disableflashlight)
<boolean> (in all games since)
- Used to disable projected texture lighting and shadows on this entity.
Distance between wheels is the distance in Hammer Units between the front axle and rear axle of your train. The rear axle moves the train and stays on the track. The front axle turns as it approaches path_tracks and does not stay on the track.
Flags
BaseTrain:
- [
1
] : No Pitch (X-rot)
- [
2
] : No User Control
- [
8
] : Passable
Disables collisions on the object.
- [
16
] : Always Fixed Orientation
- [
128
] : Rideable Train
Does not knock entities off or cause damage.
- [
256
] : Use max speed for pitch shifting move sound
- [
512
] : Not blockable by players
Inputs
BaseTrain:
SetSpeed
<float>- Set the speed of the train, as a ratio of max speed [0, 1]
SetSpeedDir
<float>- Set the speed of the train, as a ratio of max speed. Negative values reverse the direction [-1, 1]
SetSpeedReal
<float>- Set the speed of the train. Must be a positive value from 0 to max speed.
SetSpeedDirAccel
<float> (not in)
- Accel/Decel to the specified speed, as a ratio of max speed. Negative values reverse the direction [-1, 1]
SetSpeedForwardModifier
<float> (removed since)
- Applies the given modifier to all forward speeds. [0, 1]
TeleportToPathTrack
<targetname> (removed since)
- Teleport the train to the designated path track. This can be in a new path.

SetSpeedDirAccel
did later get ported in 
MoveToPathNode
<targetname> (in all games since)
- Move the train to a specific path_track, stopping when it gets there. Must be in the same path.
TeleportToPathNode
<targetname> (in all games since)
- Teleport to another path_track and stop the train. This can be in a new path.
SetMaxSpeed
<float> (in all games since)
- Set a new max speed for the train.
Stop
- Stop the train.
StartForward
- Start the train moving forward.
StartBackward
- Start the train moving backward.
Bug:If the train's corresponding path_tracks do not have "New Train Speed" set to a nonzero number, StartBackward will exhibit undesired behavior including the train freezing or moving in the wrong direction. This bug can be a pain if the train needs to ride through the path_track again at a different speed. This can be fixed by firing an "addOutput speed '#'" input at the path_track in question.
Resume
- Resume the train moving in the current direction after it was stopped via the
Stop
orToggle
input.
Reverse
- Reverse the direction of the train.
Toggle
- Toggle the train between start and stop.
Base:
AddContext
<string>- Adds to the entity's list of response contexts. See Context.
AddOutput
<string>- Assigns a new keyvalue/output on this entity. For keyvalues, some rely on extra necessary code to be ran and won't work if its simply just changed through this input. There is a strict format that must be followed:
// Format of changing KeyValues: "AddOutput [key] [value]"
//// Raw text:
"OnUser1" "!self,AddOutput,targetname new_name"
// Format of adding an Output: "AddOutput {targetname}:{inputname}:{parameter}:{delay}:{max times to fire, -1 means infinite}"
//// Raw text:
"OnUser1" "!self,AddOutput,OnUser1:SetParent:!activator:0.0:-1"
// Arguments can be left blank, but the empty blank should still be contained.
//// Raw text:
"OnUser1" "!self,AddOutput,OnUser1:ClearParent::0.0:-1"
|
ClearContext
- Removes all contexts from this entity's list.
ClearParent
- Removes this entity from the the movement hierarchy, leaving it free to move independently.
FireUser1
toFireUser4
- Fires the respective
OnUser
outputs; see User Inputs and Outputs.
Kill
- Removes this entity and any entities parented to it from the world.
KillHierarchy
- Functions the same as
Kill
, although this entity and any entities parented to it are killed on the same frame, being marginally faster thanKill
input.
RemoveContext
<string>- Remove a context from this entity's list. The name should match the key of an existing context.
SetParent
<string>- Move with this entity. See Entity Hierarchy (parenting).
SetParentAttachment
<string>- Change this entity to attach to a specific attachment point on its parent. The entity will teleport so that the position of its root bone matches that of the attachment. Entities must be parented before being sent this input.
SetParentAttachmentMaintainOffset
<string>- As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.
DispatchResponse
<string> !FGD- Dispatches a response to the entity. See Response and Concept.
DispatchEffect
<string> (removed since) !FGD
- Dispatches a special effect from the entity's origin; see also List of Client Effects. Replaced by the particle system since
.
RunScriptFile
<script> (in all games since) (also in
)
- Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.
RunScriptCode
<string> (in all games since) (also in
)
- Execute a string of VScript source code in the scope of the entity receiving the input. String quotation may be needed when fired via console.
Bug:In Hammer, using string arguments will corrupt the VMF file's structure, making the file unviewable for the next Hammer session.
Fix:Remove the string argument manually with a text editor.
CallScriptFunction
<string> (in all games since) (also in
) !FGD
- Calls a VScript function defined in the scope of the receiving entity.
TerminateScriptScope
(only in) !FGD
- Destroys the script scope of the receving entity.
SetLocalOrigin
<coordinates> (in all games since) !FGD
- Send this entity to a spot in the map. If the entity is parented to something, it will be offset from the parent by this amount.
Visible Brush:
Alpha
<integer 0–255>- Sets the entity's transparency to a number from 0 (invisible) to 255 (fully visible). Requires the entity to have its Render Mode (rendermode) set to a number other than
0
.
AlternativeSorting
<boolean>- Swaps the rendering order of the entity. Used to attempt to fix sorting problems when rendering, for example an object rendering in front of translucent materials.
Color
<color255>- Sets an RGB color for the entity.
SetDamageFilter
<targetname>- Sets a filter for this entity for when it receives damage.
EnableDamageForces
- Allows the entity to be pushed by damage done to it (usually force amount correlates with the damage done).
DisableDamageForces
- Prevents the entity from being pushed by damage done to it.
EnableDraw
(in all games since)
- Removes
EF_NODRAW
from the entity.
DisableDraw
(in all games since)
- Applies
EF_NODRAW
to the entity. Note that this is different fromrendermode 10
.
EnableReceivingFlashlight
(in all games since)
- Makes it so that the entity is lit by
env_projectedtexture
s.
DisableReceivingFlashlight
(in all games since)
- Prevents the entity from being lit by
env_projectedtexture
s. The shadow made by the texture will still cast.
Reflection:
DisableDrawInFastReflection
(in all games since)
- Turns off rendering of this entity in reflections when using
$reflectonlymarkedentities
in water material.
EnableDrawInFastReflection
(in all games since)
- Turn on rendering of this entity in reflections when using
$reflectonlymarkedentities
in water material.
Shadow:
DisableShadow
- Turn dynamic shadows off for this entity. Identical to applying
EF_NOSHADOW
.
EnableShadow
- Turn dynamic shadows on for this entity.
DisableReceivingFlashlight
(in all games since)
- This object will not receive light or shadows from projected textures.
Outputs
OnStart
- Fired when the train starts moving in either direction.
OnNextPoint
- Fires continuously every tick when the train is currently moving to its next destination.

OnArrivedAtDestinationNode
(in all games since)
- Fired when this train arrives at a destination that was specified by the MoveToPathNode input.
Targetname:
OnUser1
toOnUser4
- These outputs each fire in response to the firing of the like-numbered
FireUser1
toFireUser4
Input; see User Inputs and Outputs.