View source for Source 2013

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<span style="color:white; font-weight: bold;"> {{For|about=the Source 2013 engine branch|info about Source SDK Base 2013, and how to setting up & compiling SDK|[[Source SDK Base 2013]]|}} </span>
{{Infobox engine
| title		 = Source 2013 engine branch
| developer	 = [[Valve Corporation]]
| releasedates	 = March 15, 2013 ({{src13mp|1}}){{Cite|1}}{{Cite|2}}</br>May 2, 2013 ({{src13sp|1}}){{Cite|1}}{{Cite|3}}
| platform	 = {{Win|1}}</br>{{mac|1}}</br>{{linux|1}}</br>{{switch|1}}
| sdk		 = {{srcsdk|1}} ({{code|bin}} folder)</br>{{srcsdk13sp|1|nt=short}}</br>{{srcsdk13mp|1|nt=short}} (Legacy, prior to 2025)
| previousengine = {{src07|2}}</br>{{src09|2}}</br>{{srcmp|2}}</br><small>(all known as Orange Box branch)</small>
| nextengine = {{tf2branch|2}} <small>(replaces {{src13mp}})</small>
}}

The {{src13|4}} engine branch (also called '''SteamPipe''' branch) is the final iteration of the {{orangebox|1|nt=0}}. It was introduced by Valve in 2013 to replace the archaic [[GCF]] file format with the [[VPK]] format introduced in the {{l4dbranch|3.1}}. Major shifts in content mounting occurred, and all Valve games using the {{src09|1}} and {{srcmp|1}} engine branches were upgraded to this branch. {{hls|2}}, {{hldms|2}}, and {{hl2lc|2}} was also upgraded to this engine branch from the {{src04|1}} ({{hls}} and {{hl2lc}}) and {{src06|1}} ({{hldms}}) engine branch. The {{path|custom}} folder was added to make modding easier and was added as a mounting path for each individual Source game.

While [[SteamPipe]] was praised for simplifying how the Source engine mounts content and including previously-unreleased {{tf2|1}} code, it also broke countless numbers of mods and worsened problems already present in the {{src09|name}} branch, requires more space due to some Source 2013 games (except {{hl2ep1}}, {{hl2ep2}}, etc...) containing duplicated {{hl2|1}} base content, plus introducing more [[Half-Life: Source Bugs|bugs]] to {{hls|1}}. It also does not have most of the features that the engine branches from the {{l4dbranch|3.1}} onwards had. However, the engine branch has been polished over time, with various bugs from previous Orange Box branch have been fixed (such as [[Dropship]] container gun being non-functional in {{hl2|1}}, NPCs eyes not blinking, etc...) and is now the main branch in use by modern non-licensed engine mods.

== Sub-branches ==
{{src13|bold}} is split into three sub-branches. The first two are titled {{src13sp|3.1}} and {{src13mp|3.1}}, which succeeded both {{src09|2}} and {{srcmp|2}} branches, respectively. The two sub-branches are mostly interchangeable, but they use separate codebases, and the Multiplayer branch has some [[#Features|features]] which are not available in the Singleplayer branch.

Engine updates since 2022 to the version of {{src13mp|2}} used by {{tf2|2}} have resulted in the creation of a new semi-incompatible sub-branch, being the {{tf2branch|2}}, which has its own page. All remaining first-party Source 2013 MP games ({{css}}, {{dods}}, {{hl2dm}}, {{hldms}}) and {{src13mp|3.1|nt=sdkshort}} have been also upgraded to this new branch in February 18, 2025, completely succeeding {{src13mp|1}} branch (also referred as {{src13mp|1|nt=2}}).

{{src13sp|1}} on the other hand, despite also have new features (introduced with {{hl2|1}} Steam Deck and Anniversary Update), mod and tools built on older SDK 2013 SP code are still compatible, however, mods that are built with older SDK 2013 SP code running on top of game built on newer SDK 2013 SP code will not have all features (Steam Input, Radial fog, Classic Particles, HUD Aspect Ratio, etc.) or function correctly. Currently, Valve has yet to release the updated source code for Source SDK Base 2013 SP, but as of May 20, 2025, all Valve titles (except {{srcsdk13sp|1}}) on the SP branch now runs on updated version of it with features from {{hl2|1}} 20th Anniversary Update.

As of 2025, all games on this branch are actively being maintained with bug fixes by Valve and third-party developers. However, for Valve games, only {{src13sp|3.1}} are being maintained, as {{src13mp|name}} games have been succeeded by {{tf2branch|name}}.

{{tip|Despite the names, '''both {{src13sp}} and {{src13mp}} can be used for singleplayer'''.<br>The Multiplayer branch provides additional features ([[$lightmap|static prop lightmaps]], [[BSPZIP|BSP compression]], more [[ambient cube]]s per [[visleaf]], and slightly newer code), which may be desirable over the Singleplayer branch if not using a base mod such as {{mapbase|3.1}} and not making a single-player mod that does not modify game code.<br>
The {{tf2branch|2|nt=0}} makes some changes which break singleplayer mode, such as dysfunctional save loading[https://github.com/ValveSoftware/source-sdk-2013/issues/629] and attempting to load any map with {{cmd|maxplayers}} (singleplayer) and {{cmd|cl_localnetworkbackdoor}} both set to {{code|1}} ({{css}} or {{hl2}} "hl2" only, does not apply to "sourcetest"), and in 64-bit will also crash the game[https://github.com/ValveSoftware/source-sdk-2013/issues/610]. Some of these bug are unaffected when the game is launched in 32-bit.}}

== Features ==
<div style="float:right">[[File:HL2_GamepadUI_menu.png|340px|thumb|Screenshot of the Gamepad UI from {{hl2|4}}, introduced in 2022.]]
</div>

New since the {{Src09|2}} and {{Srcmp|2}} engine branches are:
; [[VPK]] files and {{path|custom}} folder
: First introduced on {{l4dbranch|1}} and onwards, it was later available on {{src13|1}}, which replaced the old [[GCF]] format. Source 2013 also adds support for reading any files from "custom" folder, which makes installing mods easier without overwriting original game files. In some Source 2013 games, such as {{bms|2}}, users may need to create the {{path|custom}} manually. Source 2013 uses VPK version 2.
; {{Linux|2}}, {{android|2}}, other OS and cross-platform support
: The engine can now run on Linux, Android (for {{nvidia|1}} Shield), {{switch|1}} and other operating systems/platforms. However, support for these OS outside of official games may be spotty. While {{srcmp|1}}, since February 2013 was the first branch to run on Linux, Source 2013 supports Linux (and other operating systems) out of the box.
; [[$lightmap|Static prop lightmaps]] {{src13mp|since}}{{gmod|also}}
: Static props without [[bump map]]s can now use [[lightmap]]s (albeit with [[$lightmap#Limitations and caveats|limitations]]).
; [[$color#Additional Model Parameters|Per-texel color tint masking for models]]
: <code>$blendtintbybasealpha</code> is ported from the {{l4dbranch|2}}. {{src13|1}} includes an exclusive additional parameter, <code>$blendtintcoloroverbase</code>.
; [[BSPZIP#Compression|BSP compression]] {{src13mp|since}}{{gmod|also}}
{{Note|{{gmod|2}} only supports ''loading'' compressed maps, it's BSPZIP does not support the creation of them. See the relevant github feature request [https://github.com/Facepunch/garrysmod-requests/issues/2372 here.]}}
{{workaround|Use the {{tf2branch}} version instead.}}
: [[.bsp (Source)|BSP]] maps and packed files can be losslessly compressed on both server and client.
; [[Direct3D]] 9Ex / Windows Aero DirectX Extensions {{also|{{srcmp}}{{csgo}}}}
: Improve performance depending on GPU hardware and drivers. Additionally, running those games on Windows 10/11 will automatically enable fullscreen optimization, which will allow quicker {{Key|Alt}} + {{Key|Tab}}. First introduced in {{srcmp|1}}, later available in Singleplayer titles when {{src13sp|1}} was released.
: {{Bug|tested={{hl2}}|Cannot be disabled even with {{code|mat_disable_d3d9ex 0}} (or Windows Aero DirectX Extensions set to "Disabled"). Applications such as Special K still reports the game using D3D9Ex (but not through FlipEx).</br>To actually disable D3D9Ex, you will need to use {{code|-nod3d9ex}}.}}
; Raw mouse input
: Directly taking unchanged data from mouse drivers before it goes through operating system enhancements, meaning that mouse input will be exactly 1 to 1. 

=====Steam Deck update=====
; [[Gamepad UI in mods|Gamepad UI]] {{only|{{hl2}} {{portal}} {{ez2}}}}
: Introduced in 2022, Gamepad UI is a modern controller-oriented UI designed for consoles and handhelds like {{steamdeck|1}}. With the new Gamepad UI, it was more scalable across any resolution (including 4K and higher), unlike the regular VGUI at the time (which, the higher the resolution, the text and UI will become smaller). VGUI (except on consoles {{360}}/{{ps3}}), are harder to navigate, and sometime cannot be navigate with a controller. This UI can be also enabled manually by using {{code|-gamepadui}} command line argument, or running the game when Steam Big Picture mode is active.<br>Enabling Gamepad UI will also enable Vulkan renderer. If your GPU doesn't support Vulkan or if you don't want to enable Vulkan, uses {{code|-dx9}} alongside the {{code|-gamepadui}} command.
; [[Vulkan]] renderer {{only|{{Windows}} {{Linux}}}}{{only|{{hl2}} {{portal}}}}{{also|{{l4d2}} {{p2branch}} {{csgobranch}} {{strata}} {{tf2branch}} {{xe}}}}
: A low-overhead, cross-platform graphics API, successor to [[OpenGL]].
: First introduced in 2022 with the release of Steam Deck update for {{hl2|1}} and {{portal|1}}. {{portalrtx|1}} and {{hl2rtx|1}} also uses Vulkan as part of the RTX Remix runtime. Using DXVK, a library used to translate Direct3D calls to Vulkan. This is disabled by default, but can be enabled in supported games by passing {{code|-vulkan}} into the game's launch options.

=====HL2 20th anniversary update=====
{{Note|These features are also available in {{hls|1}} (or mods running on {{hl2|1}} base instead of SDK 2013) after {{hl2|1}}'s 20th Anniversary update. It is also available in {{portal|1}} since [https://store.steampowered.com/news/app/400/view/645814564414293180 May 20] and [https://store.steampowered.com/news/app/400/view/520840214227191016 May 24, 2025 update].
}}
; [[VGUI]] High DPI support {{also|{{hls}}{{portal}}{{tf2branch}}}}
: VGUI are now properly scalable on higher resolutions such as 4K (3840x2160).
; {{w|Bicubic}} lightmap filtering {{also|{{hls}}{{portal}}{{tf2branch}}}}
: Introduced in 2024, bicubic filtering is used on [[lightmap]]s when {{cmd|r_lightmap_bicubic}} is enabled, smoothing out aliasing caused by the lower resolution of lightmaps. It can be also enabled by setting the Shader detail to "Very High".
; [[env_fog_controller|Radial fog]] {{also|{{tf2branch}}{{mapbase}}{{l4dbranch}}{{asbranch}}{{p2branch}}{{csgobranch}}{{strata}}{{hls}}{{portal}}}}
: Unlike planar-based fog, radial fog does not strengthen or weaken the apparent amount of fog in a particular spot when you rotate the camera.
: You can either use radial fog or planar-based fog by changing {{ent|env_fog_controller}} "Use Radial Fog {{mono|(fogRadial)}}" KeyValues.
: {{Note|{{hls|1}} and {{portal|1}} did not use radial fog by default, and {{hl2|1}} only uses it for certain maps, but you can force it on using the {{ent|r_radialfog_force}} (set to {{code|1}}) console command.}}
; Continue music playback after loading levels {{also|{{hls}}{{portal}}}}
: Introduced in HL2's November 26, 2024 Update, music will continue to play after the next level is loaded, instead of stopping completely like in previous versions. Can be toggled using {{code|save_transition_music}} [[console command]].

====={{tf2branch|name}}=====
{{tf2branch|1}} has its own page.

== Removed features ==
; [[Patching levels with lump files]] {{only|{{src13mp}} {{tf2branch}}}}
: Patching levels using lump files (to change the map [[entities]] without recompiling the map) is no longer possible in MP branch, and possibly {{tf2branch|1}}{{confirm}}.
; Built-in VR headset support ([[SteamVR]], Oculus VR, etc...) {{only|{{hl2}}}}
: The option to enable VR headset support in Video Options, originally introduced with the release of Source 2013, was removed in later updates of {{hl2|1}} (since 2022 Steam Deck update). Instead, player can install mods such as [https://store.steampowered.com/app/658920/HalfLife_2_VR_Mod/ Half-Life 2 VR Mod] to play in VR.

== Known issues / Report bugs ==
To report bugs or find existing issues on this engine branch, see [https://github.com/ValveSoftware/Source-1-Games/issues Source games GitHub] and [https://github.com/ValveSoftware/source-sdk-2013/issues/ Source SDK 2013 GitHub] issues page in order to prevent duplicate or outdated bug reports at the wiki.

== Availability ==
{{see also|[[:Category:Source 2013 engine branch games]]}}
=== Source code ===
Source code (game, tools) for Source 2013 Singleplayer, Multiplayer and TF2 branch is available on GitHub:
*Source 2013 Singleplayer: [https://github.com/ValveSoftware/source-sdk-2013/tree/singleplayer Source SDK 2013 GitHub repo].</br>
*Source 2013 Multiplayer (legacy version): [https://github.com/ValveSoftware/source-sdk-2013/tree/0d8dceea4310fde5706b3ce1c70609d72a38efdf Source SDK 2013 GitHub repo].
** Legacy version of SDK 2013 MP code is provided to create & update tools or mods for third-party games built on older SDK 2013 MP code only.
*TF2 branch (newer Source 2013 MP): [https://github.com/ValveSoftware/source-sdk-2013/tree/master Source SDK 2013 GitHub repo].

Full source code (such as [[Hammer]] and the rest of Source engine), are not publicly available, but it was leaked publicly in 2020.
{{Important|Source code for Source SDK 2013 MP has been updated on GitHub, now based on {{Tf2branch|1|nt=0}}. However the Source 2013 SP SDK provided on Steam (binaries) and GitHub (code), which are last updated in September 2015, currently '''does not''' include new changes from {{hl2|1}} 20th anniversary yet.
}}

== Usage ==
=== <span style="color:{{Src13sp|col}}">{{Src13sp|name}}</span> ===
==== Valve ====
* {{Code|2004}} {{hls|2}} (formerly {{src04}})
* {{Code|2004}} {{hl2|2}} (formerly {{src09}}, {{src04}})<!--note: HL2 (and possibly Lost Coast) DID NOT USE SOURCE 2006, confirmed via retail Orange Box (ran on build 2707) -->
* {{Code|2005}} {{hl2lc|2}} (formerly {{src04}})
* {{Code|2006}} {{hl2ep1|2}} (formerly {{src09}}, {{src06}})
* {{Code|2007}} {{hl2ep2|2}} (formerly {{src09}}, {{src07}})
* {{Code|2007}} {{portal|2}} (formerly {{src09}}, {{src07}})
** {{Code|2022}} {{portalrtx|2}}
** {{code|2022}} {{pcc|2}} ({{portal|1}} on {{switch|1}})
* {{Code|2013}} {{srcsdk13sp|4.1}} (AppID: 243730 - {{Steam|launch/243730|Click to Install}})
{{Note|All Valve games except {{srcsdk13sp|1}} now runs on updated version of {{src13sp|1}} which have features from {{hl2|1}} 20th Anniversary Update.}}
==== Third-Party ====
* {{Code|2010}} {{nh2|2}} (formerly {{src07}})
* {{Code|2015}} {{hl2u|2}} (earlier version)
* {{Code|2022}} {{divchr|2}}
* [[:Category:Source 2013 SP engine branch games|More...]]
==== With {{mapbase|2}} ==== 
* {{code|2017}} {{ez|2}}
** Originally released before Mapbase. It was later based on Mapbase after updates.
* {{code|2018}} [[Map Labs]]
* {{code|2022}} {{ez2|2}}
* {{Code|TBA}} {{hl2rtx|2}} (Demo released on March 18, 2025.)

=== <span style="color:{{Src13mp|col}}">{{Src13mp|name}}</span> ===
All first-party games and Source SDK Base 2013 MP have been upgraded to the {{tf2branch|1}}.

If you want to use legacy version of {{srcsdk13mp|3.1}}, to play older mods (or use tools) built prior to {{tf2branch|1}}, follow the instructions:
:1. Open Steam, go to '''Source SDK 2013 Multiplayer''', right click Properties
:2. A window will open. Go to "Betas", select {{Code|previous2021}} beta branch.
:3. Steam will automatically re-download the files. Once it's done, run Source SDK Base 2013 MP as normal, or use it's tools.

==== Third-party ====
* {{Code|2007}} {{ff|2}} (in development, will replace {{src06}})
* {{code|2007}} {{Synergy|2}} (formerly {{src04}}, {{src06}}, {{src07}})
* {{Code|2007}} {{zps|2}} (formerly {{src07}})
* {{Code|2008}} {{Empires|2}} (formerly {{src07}})
* {{Code|2009}} {{obsc|2}} (in development, will replace {{src07}})
* {{Code|2011}} {{nmrih|2}} (formerly {{src09}}/{{srcmp}}{{confirm}})
* {{Code|2013}} {{cso2|2}}
** Modified with features such as [[CSM]] and LZMA-compressed [[VTF|VTF(s)]].
* {{Code|2014}} {{fof|2}}
* {{Code|2016}} {{bb2|2}}
* {{Code|2018}} {{hdtf|2}} (formerly {{src13sp}})
* [[:Category:Source 2013 MP engine branch games|More...]]
==== With {{mapbase|2}} ==== 
{{Note|Mapbase MP is currently not yet supported nor available on ModDB/GitHub Releases (code for MP is available however), but TF2 Classic, an Source 2013 MP game, uses Mapbase code (likely both SP and MP version).}}
* {{code|2014}} {{tf2c|2}} (added since patch 2.2.0)

=== Third-party Source 2013 branches ===
The following games use neither {{src13sp}} nor {{src13mp}}, but rather use custom (heavily modified) branches forked earlier versions from both Source 2013 branches, with newer features added on. As such, they may or may not include all features from newer first-party versions of Source 2013, such as [[BSPZIP#Compression|LZMA-compressed BSPs]] or [[$lightmap|lightmapped MDLs]].

* {{Code|2006}} {{gmod|2}} (which also support some features from {{asw|1}}, {{p2branch|1}} and onwards, such as partial VTF 7.5 support; formerly {{src06}}, {{src07}}, {{srcmp}})
** Also, with March 2025 update, uses some code from {{tf2branch|2}} for fixing some exploits.
* {{Code|2015}} {{bms|2}} (has its own branch known as {{xe|2}}, had features such as [[CSM]], [[deferred lighting]] and more; formerly {{src07}})

== System Requirements ==
These system requirements applies to [[Source SDK 2013]] (and some Source 2013 game) only. Some other games may have their own system requirements.
{{Sysreq
| OSfamily = Windows

| minOS		= [[WP:Windows XP|XP]] or later (SP - pre-Steam Deck update, MP - all versions)<br>{{win7|1|nt=vista|linkto=vista}}, {{Win7|1|nt=7|linkto=4}} or later (SP - post-Steam Deck update)
| minCPU	= 1.7 GHz and/or Dual-core
| minRAM	= 1 GB (XP)<br>2 GB (Vista and later)
| minHD		= 10 GB (space would be increased depending how many [[Sourcemods|Source SDK mods]] is installed)
| minGPU	= NVIDIA GeForce 6xxx series, ATI Radeon X1600, Intel HD Graphics 3000 (with 128MB [[WP:Video random-access memory|VRAM]])
		  <br> [[WP:Direct3D|Direct3D]] 9.0 compatible [[WP:Video card|video card]] (with atleast DirectX 8.0 compatibility level or higher)
}}
{{Note|To play on XP and Vista, run the game without Steam by directly launching the {{code|hl2.exe}} executable. The latest version of Steam requires Windows 10, but the last version of Steam for Windows 7/8/8.1 still support running many Source 2013 games.
Some games may requires {{code|-game <gamename>}} [[Launch options|command line]].}}

{{Sysreq
| OSfamily = Mac

| minOS		= [[WP:OS X|OS X]] 10.5.8, 10.6.3 (up to 10.14.6)
| minCPU	= 2.0 GHz and/or Dual-core
| minRAM	= 1 GB
| minHD		= 10 GB (space would be increased depending how many [[Sourcemods|Source SDK mods]] is installed)
| minGPU	= NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000
		  <br> OpenGL 2.1 compatible
| minaudio	= OpenAL compatible
}}

{{Note|By default, 32-bit executable are no longer supported after macOS Catalina (10.15), meaning that SDK 2013 will not work out of the box. User can manually build Intel 64-bit/Apple Silicon executable by [https://www.applegamingwiki.com/wiki/Half-Life_2#Native following this guide]<!-- not sure if this is legal for it to be mention here as the guide rely on using the modified leaked source engine source code, through user can build HL2 for Apple Silicon using official (non-leaked) code. -->.

Alternatively, with Steam Proton or Wine, you can play the the Windows version of the game on Mac.
}}

{{Sysreq
| OSfamily = Linux

| minOS		= Ubuntu 12.04, SteamOS 1.0 or later<br>Other Linux distros supported.
| minCPU	= 2.0 GHz and/or Dual-core
| minRAM	= 1 GB
| minHD		= 10 GB (space would be increased depending how many [[Sourcemods|Source SDK mods]] is installed)
| minGPU	= NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000
		  <br> OpenGL 2.1 compatible
| minother	= 
}}

{{Note|The system requirements for Linux are unofficial, based off Windows/Mac info, as well as other Source games that support Linux, such as Portal 2.}}

== See also ==
* [[Source SDK 2013]]
* [[Source SDK 2013 community repos]]

{{Branch-navbox}}
[[Category:First-party engine branches]]
{{references|1=
{{ref2|cite id=1|[https://docs.google.com/spreadsheets/d/1ldzhd6vxd-03le5ymesUeG-hLWmxLpH79ajayeYDUNs/ Source Engine Build List - Google Spreadsheets]
[[Source/Engine_versions|Updated Source Engine Build List - VDC]]
}}
{{Ref2|cite id=2|{{Steamdb|depot/232331/manifests/|CS:S Windows client - Manifests}}{{Steamdb|depot/232371/manifests/|HL2:DM Windows client - Manifests}}{{Note|The earlist build available on manifests (for {{src13mp|1}} games) are dated March 15, 2013. {{hl2dm|1}} first SteamPipe build was compiled on {{code|Mar 13 2013}} (using {{cmd|version}} console command).}}
}}
{{Ref2|cite id=3|{{Steamdb|depot/222/manifests/|Half-Life 2 Windows client - Manifests}}{{Steamdb|depot/402/manifests/|Portal Windows client - Manifests}}{{Note|The earlist build available on manifests (for {{src13sp|1}} games) are dated May 2, 2013 (Portal), and May 9, 2013 (Half-Life 2). {{hl2|1}} first SteamPipe build was compiled on {{code|May 7 2013}} (using {{cmd|version}} console command).}}
}}
}}