func_tracktrain

Not to be confused with func_tanktrain.

GoldSrc

Source Engine

 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.

Note:Unless the 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.

Note:Tracktrains only update their movement direction 10 times per second. At higher speeds, this can result in them overshooting the track, especially with sharp turns. The older func_train entity is not affected by this issue, so it may be a suitable alternative for high-speed objects.

Bug:Due to poor coding, the 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.

Bug:Trains stop short at a distance from their targets, regardless of speed. The higher the speed, the further away it will stop from the path_track. At low speeds, this is negligible.

Warning:Trains need to have the same parent as the track nodes they follow (such as no parent at all). Failure to obey this rule is an intentional crash.

In code, it is represented by theCFuncTrackTrainclass, defined in thetrains.cppfile.

Keyvalues

BaseTrain:

First Stop Target (target) <targetname>

The name of the first path_track in the train's path. The train will spawn at this path_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_tracks or SetSpeed 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.

Note:The above three keyvalues are !FGD in Left 4 Dead and later, but appear to still exist in the engine.

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

Name (targetname) <string>

The name that other entities use to refer to this entity.

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.

• 0: Normal
• 1: Color
• 2: Texture
• 3: Glow
• 4: Solid/Alphatest
• 5: Additive
• 6: Removed, does nothing
• 7: Additive Fractional Frame
• 8: Alpha Add
• 9: World Space Glow
• 10: Don't Render

Render FX (renderfx) <choices>

Various somewhat legacy alpha effects.

Bug:Alpha effects from 0 to 10 are unavailable due to the bug in code in Counter-Strike: Global Offensive

• 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.

Maximum DX Level (maxdxlevel) <choices> (removed since )

• Default (no bounding)
• DX7
• DX8
• DX8.1
• DX9 SM2
• DX9 SM3

SystemLevelChoice:

Minimum Effect Details Level (mincpulevel) <choices> (in all games since )

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" formincpulevel, "High" formaxcpulevel)
• 1: Low
• 2: Medium
• 3: High

Note:The keys' names are because of the cpu_level command, the command Effect Details uses.

Minimum Shader Details Level (mingpulevel) <choices> (in all games since )

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" formingpulevel, "Very High" formaxgpulevel)
• 1: Low
• 2: Medium
• 3: High
• 4: Very High

Note:The keys' names are because of the 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.

Note:The above three inputs appear to have been added to Source 2007 games post-release for TF2's Payload mode, but did not make it into later games, resulting in their apparent "removal". However, SetSpeedDirAccel did later get ported in Left 4 Dead 2.

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.

LockOrientation  (in all games since )

Lock the current orientation of the train.

UnlockOrientation  (in all games since )

Unlock the current orientation of the train.

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 or Toggle 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 to FireUser4

Fires the respectiveOnUseroutputs; 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 thanKillinput.

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.

Use  !FGD

Same as a player invoking +use; no effect in most cases.

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.

Note: Backtick characters ` are replaced with quotation marks at runtime, allowing quotation marks to be used when normally not possible.

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.

SetLocalAngles <angles> (in all games since ) !FGD

Set this entity's angles.

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 from rendermode 10.

EnableReceivingFlashlight  (in all games since )

Makes it so that the entity is lit by env_projectedtextures.

DisableReceivingFlashlight  (in all games since )

Prevents the entity from being lit by env_projectedtextures. 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.

EnableReceivingFlashlight  (in all games since )

This object may 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.

Warning:In the default FGD, this is incorrectly listed as "OnNext" and has an incorrect description ("Fires when this train picks a new point to move towards (and just after OnStart)")

OnArrivedAtDestinationNode  (in all games since )

Fired when this train arrives at a destination that was specified by the MoveToPathNode input.

Targetname:

OnUser1 to OnUser4

These outputs each fire in response to the firing of the like-numbered FireUser1 to FireUser4 Input; see User Inputs and Outputs.

OnKilled  (only in )

This output fires when the entity is killed and removed from the game.