Source 2004
Source 2004 is the original build of the Source engine that Half-Life 2, Half-Life: Source and Counter-Strike: Source shipped with. It was succeeded by the Source 2006 engine branch with the release of Half-Life 2: Episode One.
No current Valve titles hosted on Steam use this particular engine branch, as it is outdated.
Vampire: The Masquerade – Bloodlines still runs on a custom version of the engine, similar to the engine used in the Half-Life 2 Beta leak. However, it uses a proprietary texture format and BSP version 17, and support Bink videos.
SiN Episodes also likely used the last?[confirm] build of Source 2004, or possibly an early version of the Source 2006 branch previously used by 
Half-Life 2: Lost Coast, combined with Source 2004 code[confirm], which contains few commands related to the HDR Rendering which was non-functional ("mat_hdr_enabled").
Features
- Indoor/Outdoor environments
- Deformable terrain
- Subdivision surfaces, diffuse & specular bump maps
- 3D Skyboxes extend the horizon and add parallax on distant objects
- Dynamically rendered organics (grass, trees, etc.)
- Texture filtering options
- Anisotropic filtering allows textures on far distances to look sharper and less blurry.
- featuring ranging from Bilinear, Trilinear, Anisotropic 2x up to 16x.
- Blob shadows
- Displacement map texture blending
- Detailed and believable characters
- Refractions with the use of a du/dv map
- Dynamic shadows
- Directional lighting on world brushes using normal maps
- Cube-mapped specular effects
- Cube-mapped water
- Low-quality reflective water (used sparingly)
- Soft edge dynamic shadows
- Refractions with the use of a bump-map
- High-quality reflective water
- Realistic eyes
- Focus on player/object, not simply parallel views
- Proper eye bulge for realistic eye reflections
- Simulated musculature provides outstanding emotions, speech, and body language
- Language independent speech, characters can speak naturally in many languages
- Skeletal/bone system for animation
- Layered animation system can synthesize complex animations out of several pieces
- Uses Havok physics engine, licensed from Havok Group (now acquired by Microsoft)
- More responsive world with realistic interactions
- Sounds & graphics follow from physics
- AI characters can interact with physically simulated objects
- Ropes/cables, machines, constraint systems, ragdoll physics
- Can be controlled by level design
- Kinematic animated bone followers
- Custom procedural physics controllers
- Vehicles
- Wheels slip and skid
- Realistic suspensions with springs on each wheel
- Realistic leaning during acceleration/deceleration and turning
- Individually tunable parameters such as horsepower, gearing, max speed, shift speed, tire material, tire friction, spring tension/dampening, etc.
- Multiple players in a vehicle in multiplayer
- Hovercraft support for cheaper simulation
- I/O system allows level designers to control AI
- Sophisticated navigation: characters that run, fly, jump, crouch, climb stairs and ladders, and burrow underground
- AI senses things using sight, sound, and smell
- AI relationships determine friend/foe status of other entities
- Battle AI allows squads of AI characters to operate together, know when to advance, retreat, lay cover fire, etc.
- env_terrainmorph
- env_terrainmorph dynamically morphs displacements by pulling vertices along a normal, similar to the Paint Geometry tool in Hammer.
- DirectX
Availability
Source code for this branch is no longer officially available. Most Valve games introduced with Source 2004 are now currently using Source 2013 Singleplayer or Source 2013 Multiplayer.
An archive of the 2004 SDK is available on GitHub.
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
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)
