Source 2004
September 26, 2005 (
, v2)
Source 2004 is the original build of the Source engine that Half-Life 2, Half-Life: Source and Counter-Strike: Source shipped with, then subsequently updated with the release of Day of Defeat: Source (and later Half-Life 2: Lost Coast),[1] adding some features (such as HDR and Color Correction) which would become standard with Source 2006.[1] The Source 2004 engine was succeeded by the Source 2006 engine branch with the release of Half-Life 2: Episode One, but Half-Life 2 and Half-Life 2: Lost Coast continues to runs on this branch (without any updates since April 2006) until 2010 (when it was upgraded to Source 2009).
No current Valve titles hosted on Steam use this particular engine branch, as it is outdated.
It was distributed in 
source engine.gcf.
Vampire: The Masquerade - Bloodlines still runs on a custom version of the engine which is more similar to the engine used in the Half-Life 2 leak (unofficially referred to as Source 2003). However, it uses a proprietary texture format, Python for scripting, BSP version 17, and supports Bink videos.
SiN Episodes runs on modified version of Source 2004 v2 (/
), which contains few commands related to the HDR Rendering which was non-functional ("mat_hdr_level"), aside from that it also stripped BSP 20 support from Day of Defeat: Source and HL2 Lost Coast.
The engine versions for this branch are build 2106 up to 2497 (Protocol 5-7). The second version of Source 2004 (introduced with Day of Defeat: Source, adding HDR and other new features), started with build 2497 until 2707 (Protocol 7).[2]
Features
- Support for
Original Xbox game console - Steam Friends & Parlor Games menu (removed in Source 2006 since July 2007)
- In-game friends list & instant messaging, allowing you to chat in-game without Alt + Tab ⇆ to Desktop and open Friends in Steam client. Originally present before it was eventually removed in July 31, 2007 engine update (Source 2006 only), as many of it's functionality are replaced by Steam Overlay which is introduced around September 2007 (or earlier in 2007). This removal does not applies to Half-Life 2 (which runs on Source 2004 build 2707) and other Source 2004 games.
As of 2025, the friends feature (still works with latest Steam client) only works on Source 2004 games since 2006 (when Friends Beta was introduced), and all Source 2006 games before the "Friends" feature being removed. It can send messages to friends (the message is shown on Steam client, but not in-game). The Friends feature on older build of Source 2004 and GoldSrc (both from 2005 or earlier) no longer works, since the old Steam servers was offline, or using deprecated Steam API. - Shader Model 2.0 only
- Anti-aliasing
- Up to 6x MSAA. 8x MSAA unofficially supported through mat_antialias 8, but will reset to 4X on next launch. MSAA 8X can be also forced through GPU drivers control panel.
- 6x MSAA does not work on modern graphics card. Only 4x works.
- DirectX 9.0
- Uses Direct3D 9.0, with support for these hardware levels:
- DirectX 6.0 (dxlevel 60) level (not officially supported, but works)
- DirectX 7.0 (dxlevel 70) level
- DirectX 8.0 (dxlevel 80) level
- DirectX 8.1 (dxlevel 81) level
- DirectX 9.0 (dxlevel 90) level
- Inputs
- Support DirectInput controller only
Since Lost Coast & DOD:S engine update
Day of Defeat: Source,[1] and later Half-Life 2: Lost Coast, a tech demo. This image compares between LDR, LDR with Bloom and HDR.- High Dynamic Range rendering[1] (DX9 SM2)
- HDR rendering (also known as HDR lighting) simulates brightness values outside computer monitors' actual range, before downconverting to
Standard Dynamic Range. This mainly involves "blooming" colors above 100% brightness into neighboring areas and adjusting a virtual camera aperture to compensate for any over-exposure that results. HDR rendering gives gives richer colors, better contrast and finer gradients. Not to be confused with HDR display output. - While being attributed to Source 2006, this feature was first introduced with Half-Life 2: Lost Coast and Day of Defeat: Source (both runs on updated version of Source 2004).[1][3][4] Half-Life 2 was also upgraded to the Lost Coast version of Source 2004, but not all Half-Life 2 maps are HDR-compiled by default, leaving the HDR feature unused. SiN Episodes also runs on this version and feature mat_hdr_level console command, but support for HDR was stripped in code which leaves it non-functional.
- Film grain post-processing effect
- Used in Day of Defeat: Source.
- Color correction
- Alter the color balance of an image to achieve a desired effect. For example, in Day of Defeat: Source, the color has been adjusted to be more desaturated.
- Direct3D 9 - Shader Model 3 (DirectX 9.0+ feature level/dxlevel 95)
- Unlocks greatly improved shader performance.
- Commentary System
- Allows DVD-like director's commentary to be embedded inside levels. Commentary System was used in Half-Life 2: Lost Coast, but was introduced (and unused) with the release of Day of Defeat: Source.
Removed features (post-launch)
- 64-bit binaries
- In December 2005,
Half-Life 2 and Half-Life 2: Lost Coast was updated to add 64-bit support, allowing it to access more than 2GB (4GB with LAA) of RAM, and increase performance slightly. However it was later discontinued and removed due to its instability on some systems. 64-bit support was later reintroduced with Counter-Strike: Global Offensive (on Mac/Linux), and later the Team Fortress 2 branch, without any technical issues (aside from singleplayer mode on Team Fortress 2 branch which doesn't function correctly). The Titanfall branch also has 64-bit binaries.
Availability
The source code for this branch is no longer officially available. All Valve games that run on Source 2004 are now currently using Source 2013 Singleplayer or the Team Fortress 2 branch (formerly Source 2013 Multiplayer).
An archive of the 2004 SDK is available on GitHub. SDK Base for this branch does not exist as mods using 2004 SDK are base directly on Half-Life 2 (requires older version of the game running on 2004 branch), instead of Source SDK Base.
Usage
The following games are still based on, or currently using Source 2004.
Valve
- 2005
Half-Life 2 (Xbox)
Third-Party
- 2004 Vampire: The Masquerade - Bloodlines (Beta version)
- 2006 SiN Episodes
Known issues
Bug:All Source 2004 and 2006 games suffered from the fog bug that makes it more dense than usual, which was affected on newer GPUs (since GeForce 8000 series or newer AMD/ATI GPUs) and newer drivers. This has been fixed on NVIDIA systems since driver version "516.5x" (confirmed on RTX 3060),[5][6] but is likely still present on AMD/Intel. This issue is not affected when using dxlevel 81 or lower, only dxlevel 90 or higher.
Additionally, using any D3D9 wrapper (which translates to D3D11, D3D12 or Vulkan), like 
dgVoodoo 2 (even on systems with newer NVIDIA drivers that fixes this issue) on this branch, can also cause this issue.
Note:This driver fix also makes VGUI UI (on DirectX 9 mode) looks dark exactly like DirectX 8 or lower. However, VGUI (in DirectX 9) will still look bright on Source 2007 and later., 
v34, )Bug:Much older Source 2004 titles may not run on modern versions of Windows, and can display the error "Memory lower than 128 MB" when trying to run the game.
Fix:Right click 
hl2.exe (or other .exe for some games), set Compatibility mode to "Windows XP SP3".)
Important:All Source games prior to Left 4 Dead engine branch or Source 2013 are known to have slower Alt + Tab ⇆ and can occasionally crash easily, especially when running on modern version of Windows.System Requirements
Minimum Specs :
- OS: Windows 98 / ME, 2000, XP or later
- CPU: 1.2 GHz
- RAM: 256 MB
- Nvidia GeForce FX 5700, ATI Radeon 9500 (with 128MB VRAM)
- Direct3D 9.0 compatible video card (with atleast DirectX 6.0 compatibility level or higher)
Note:As Steam dropped support for previous version of Windows, and this branch requires Steam (unlike Source 2013), all Source 2004 branch games (except Half-Life 2 Collector's Edition) will require Windows 10 or later. Source 2004 games are still currently playable with the last version of Steam running on Windows 7/8/8.1.See also
References
| CollapseReferences | ||||||||
|---|---|---|---|---|---|---|---|---|
|
