The Source Engine
Half-Life 2's incredibly open-ended gameplay, astonishing graphics, amazing sound, realistic A.I,
real-world physics, and other outstanding elements would not have been possible if the Source Engine had not been used
to build the realism factor in Half-Life 2. Below are a long and in-depth list of the Source Engine's mighty features.
Graphics Renderer Features:
Microsoft® DirectX-3D® 9.0 graphics renderer API support.
Revision 2.0 (and backwards) of Pixel Shaders and Vertex Shaders, normal mapping, displacement mapping in LOD on character, weapons, items, and world models.
HLSL Authoring shader support.
Dynamic cube, cubic, and environment mapping
Dynamic lights, lightmaps, vertex maps, shadowmaps, and many other light types.
High-Dynamic Range lighting with integer formats and FP16 texture filtering/blending targets color precision capabilities & support.
Real-time water with pixel-shaded reflection, refraction and fresnel effects
Advanced particle system that can create realistic volumetric fog, intense volumetric smoke, great 3D sprite explosions, and emit other models and sprites.
Projected render-to-texture soft, fuzzy edged high-resolution shadows enable a huge amount of characters per scene without a performance hit.
Occluder entities for visibility blocking instead of 'nocliping through' (AKA ghosting) corpses and other static models.
-Deformable geometry and terrain
-3D skyboxes extend the horizon and expand the distance and parallax map / objects possibilities.
-Dynamically rendered organic dynamic and static props (grass, rocks, trees, etc)
-Subdivision surfaces, displacement maps, diffuse, ambient, reflection, refraction, & specular normal maps
-Real-time specular based radiosity dynamic lighting
-Effects include but are not limited to: real-time particles, shader defined beams, volumetric smoke, sprite sparks, detailed pixel shaded blood, environmental effects like volumetric fog and realistic rain
Direct-X 7 to Direct-X 9 generation graphics hardware support.
Advanced Materials System Features:
Instead of traditional textures, Source defines sets of materials that specify what the object is made from and the texture used for that object. A material specifies how an object will fracture when broken, what it will sound like when broken or dragged across another surface, and what that object’s mass and buoyancy are. This system is much more flexible than other texture only based systems.
Materials can interact with objects or NPCs such as mud or ice or sand for vehicles to slide/lose traction on.
Multiplayer Network Code Features:
Time play and hardcore gamer tested by millions of gamers all around the globe
Full support for both LAN based multiplayer and Internet based multiplayer games.
Prediction analysis for interpolating collision/hit detection system.
Professional Optimizations for high-latency, high-packet loss dial-up connections to low-latency, low-packet loss broadband connections.
Advanced Characters Features:
Extremely detailed and believable character models
Very realistic eyes
-Focus on player/object, not simply parallel views
-Proper eye "bulge" for realistic eye reflections
Simulated musculature provides emotions, speech and body language
Language independent speech, characters can naturally speak in many languages
Skeletal/bone system for animation
Layered animation system can synthesize complex animations out of several pieces
Physics System Features:
More responsive world with realistic interactions thanks to ragdoll physics system
Sounds & graphics are capable of reacting to the realistic physics
AI characters can interact with physically simulated objects
Ropes/cables, machines, constraint systems, ragdoll physics
Physics can be controlled by level design
Kinematic animated skeletal bone system followers
Custom procedural physics controllers
-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
Advanced Character A.I Features:
I/O system allowing 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, 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.
A new AI system has recently been implemented for the upcoming Aftermath expansion pack for working with Allies and collaborative action, an improvement of the previous AI basically.
Audio system features:
5.1 surround sound, 4 speaker surround
High-quality 3D spatialization
Custom software DSP
Automatic DSP based on environmental geometry
16-bit 48KHz & 24-bit 96KHz, stereo wave data with all features
MP3 decompression (requires Miles license)
Support for audio streaming on any wave
Real-time wave file stitching
Pre-authored Doppler effect encoded waves
Pre-authored distance variant encoded waves
Server browser - Displays all active game servers and allows a player to choose which one to participate on. Players can filter and sort server lists in order to speed up the display and selection of a server.
Friends instant messenger - Allows players to message each other both in and out of the game as well as join friends in existing games. No more confusion about what server your friends are on, you can easily join with this feature.
VGUI - Valve's custom GUI interface mimics most of the windows controls but is rendered using the Source engine for both in game and out of game uniform UI display. VGUI is platform independent and is Unicode compliant for ease of localization
Core game mechanics programming langauge features:
All code written in C/C++ using Visual Studio 6.0. Easily and quickly derive new entities from existing base classes.
Internal context sensitive performance monitoring system
Graphics Renderer frame-rate benchmark performance measurement tools built into the engine
Modular code design (via DLL's) allows swapping out of core components for easy upgrading or code replacement
Direct-X 9 shaders all written in HLSL
-Facial expression tool used to craft speech and emotions
Valve Hammer Editor
-WYSIWYG World editor
-Create world brushes
-Place detailed world models and AI NPCs
-Set navigation points/paths for NPCs
-Place triggers, clip brushes, logic etc.
-Allows level designer to hook up I/O between entities to control AI
Half-Life Model Viewer
-Full, real-time 3D model previewer
-Rotate models in any direction in real-time
-Setup skeletal hit boxes
-View ragdoll physics hull
-View normal maps
-Wireframe, UV map, mesh, shaded or textured view modes
-3D Model compiler
Vbsp, Vrad, Vvis, VMPI
-Map compilation tools (bsp, lighting and visibility)
-VMPI distributed compilation tool allowing level compiles to be
spread across many PC's greatly reducing compile times
-Soft Image | XSI, 3D Studio Max and Maya .smd exporters for exporting 3D models
That's it for the current list of engine features, more will be added in when more information arrives.