Half-Life 2: Lost Coast

Half-Life 2: Lost Coast is a small additional level for the 2004 first-person shooter video game Half-Life 2. Developed by Valve Software, it was released on October 27, 2005, through the Steam content delivery service as a free download to owners of the Microsoft Windows version of Half-Life 2. Lost Coast serves as a technology demonstration, specifically showcasing the high dynamic range rendering implemented in the Source engine. The level was designed with a variety of appropriate environments to emphasize these effects. In addition, Lost Coast was the first video game developed by Valve to allow developers to explain various elements of design as the player progresses through the level.

Lost Coast follows Half-Life protagonist Gordon Freeman as he travels up a coastal cliff to destroy a Combine artillery launcher in a monastery, which is firing on a nearby town. The Lost Coast level was originally created for Half-Life 2, but was ultimately removed from the game. As a result, it has several minor story details that were not included in Half-Life 2. The level received a generally positive reception, and there was consensus among reviewers that the new features included in Lost Coast should be integrated into future games released by Valve.

Plot
Lost Coast opens with the protagonist, Gordon Freeman, gaining consciousness near a group of decaying piers, underneath the shadow of a large Byzantine-style monastery set up on rocks and overlooking the small coastal town of St. Olga. An unnamed man referred to in the commentary as "The Fisherman" standing on a dock recognizes Freeman, although he cannot accurately remember his name, and directs him to the monastery, which the enemy Combine are using as a platform to launch artillery shells filled with Headcrabs into the town. He tells Gordon to "take out that gun".

The fisherman opens a gate leading to a winding path along the side of the outcrop the church is located. As Freeman proceeds up the cliffside to the monastery, he encounters heavy resistance from Overwatch Soldiers who rappel down the cliff to engage him. As he proceeds up the cliff, a launcher based in the church at the top begins bombarding the nearby town with headcrab shells. Upon reaching the top of the cliff, the player finds the church and its courtyard unguarded The church itself is relatively undamaged except for the religious paintings on the walls, the faces of all but a few of the characters having been rubbed away.

On one wall of the structure, the Combine have constructed the shell launcher. At a regular interval shells are loaded into the chamber and launched at the town. When the player destroys the launcher by jamming the mechanism with debris, an alarm is triggered, prompting the Combine to launch a second attack on the church itself, with a Hunter-Chopper acting as air support. The player must fight their way out of the church and shoot down the Hunter-Chopper with an RPG. After completing the task, the player must ride an elevator back down to the docks to meet The Fisherman. He congratulates Freeman on his success, invites him to a feast in St. Olga, and the screen fades out. The fisherman exclaims that Gordon is "getting all fuzzy round the edges" as the level ends.

Development
Level design

Half-Life 2 Lost Coast was originally conceived as a level in Half-Life 2, but was later discarded during development. As a result, Lost Coast features minor storyline details that were removed from Half-Life 2, such as the Headcrab artillery launchers. Each area of the level was designed with a specific purpose. An Eastern Orthodox architectural style was deliberately chosen for the monastery, as buildings of this type "are very colorful and have a large variety of materials" and are "often lit naturally, with extremes of darkness and brightness," providing an ideal showcase for the HDR lighting effects. Valve also thought that the use of a monastery would help provide a starker contrast between old human architecture and futuristic Combine technology found within it. The cliffside that leads to the monastery had a gameplay-oriented purpose, and was meant to emulate a similar cliffside combat scene in Half-Life. The cliffside also forces the player to be observant of threats from above and below, breaking from normal horizontal combat. The monastery's courtyard was designed as an area where the player recovers from the cliffside combat, while also presenting a contained combat arena later in the level in which the player must hold their ground while they are attacked from multiple directions.

High dynamic range rendering

The goal of Lost Coast was to demonstrate the new high dynamic range (HDR) rendering implemented into the Source game engine. Valve first attempted to implement HDR rendering in Source in late 2003. The first method stored textures in RGBA color space, allowing for multisample anti-aliasing and pixel shaders to be used, but this prevented alpha mapping and fog effects from working properly, as well as making textures appear sharp and jagged. The second method involved saving two versions of a texture: one with regular data, and the other with overbrightening data. However, this technique did not allow for multisample anti-aliasing and consumed twice as much video card memory, making it unfeasible. The third method, shown at the E3 convention in 2005, used floating point data to define the RGB color space, allowing for reasonably efficient storage of the HDR data. However, this method also did not allow for multisample anti-aliasing, and was only compatible with Nvidia video cards, leaving ATI cards unable to run HDR.The fourth and final method compromised between the second and third methods, using overbrightening textures sparingly and allowing ATI cards to render HDR in a different way to the Nvidia ones while nearly producing the same end result.

The final version of Valve's HDR technology adds a significant number of lighting effects to the engine, aimed at making the game appear more realistic. Bloom shading was introduced, blurring bright edges in the game world and emulating a camera's overexposure to light. This is combined with exposure control to tailor the effect to represent the human eye. For example, as the player exits a dark area into a light area, the new area is initially glaringly bright, but quickly darkens, representing the adjustment of the player character's eyes to the light. New cube mapping techniques allow the reflection cast by an object to correspond with the brightness of the light source, and lightmaps enable light bouncing and global illumination to be taken into account in the rendering. Refraction effects were added to make light account for the physical attributes of an object and to emulate the way light is reflected by water. The Lost Coast level is specifically designed to showcase these effects. It uses the sea and beach as opportunities to demonstrate water-based effects, the monastery to demonstrate bloom from its whitewash walls, and the sanctuary to provide the means to show refraction through stained glass windows and cube maps on golden urns and candlesticks.

As a technology showcase, Valve considered Lost Coast to have very demanding system requirements. The game runs on computers with specifications lower than what is recommended, albeit without some key features such as HDR. If a non-HDR capable card is used, the developer commentary is changed slightly to reflect this. For example, Gabe Newell would describe the effects that are seen in a different manner.

Developer commentary
Aside from visual fidelity and HDR, Lost Coast also acted as a testbed for a commentary system where, when the option is enabled, additional items appear in-game that can be interacted with to play audio commentary, each piece ranging anywhere from ten seconds to a minute of commentary. Players will hear the developers talk about what they are seeing, what is happening, why the team chose to do what they did, what kind of challenges they faced, and so on. Commentary tracks are represented by floating speech bubbles known as commentary nodes. To listen to a commentary track, the player must place the crosshairs over it, and presses the  key. Doing the same again will stop the commentary track. Commands can be run when a commentary track starts and stops; in Lost Coast, this is used to completely disable the AI while the track plays. However, in Half-Life 2: Episode One, running a commentary track renders the player invulnerable to in-game damage for the time being rather than disabling the AI.

Valve has added the commentary system to all subsequent games.

Recommended system specifications



 * Processor: Pentium 4 2.4GHz or AMD 2800+
 * Memory: 1 GB RAM.
 * Graphics Card: DirectX 9 native
 * 335 MB disk space (with Half-Life 2 installed)

Lost Coast is a 98 MB compressed download from Steam.

Despite some claims, Lost Coast can run on computers with specifications lower than those listed above, albeit without some of the key visual features, such as HDR. It should be noted that a computer with the bare minimum specifications to run Half-Life 2 will not be able to run Lost Coast.

Behind the scenes

 * The subtitles file indicates that the game was intended to be longer, with The Fisherman staying with the player for a longer time and mentioning Bullsquids.

Trivia

 * The Fisherman does not have a physics model and, if killed, he will either crash the game or he will do a reference pose.


 * The Hunter-Chopper that opposes the player towards the end of the demo behaves and even sounds like the Combine Gunship; it shoots down incoming rockets and its pulse gun is much more accurate.


 * The Fisherman is the first Source character whose face was made from scratch without a real-life model.


 * In the Source SDK Base, a flyby of this level can be launched as a video stress test.


 * The shell launcher, despite its printed warning sign stating that its moving parts can crush objects, can be disabled with any available physics object small enough to pick up and fit into it. Oddly enough, it cannot be destroyed with a grenade or any other weapon.


 * Half-Life 2: Lost Coast is currently the only game to not get updated to use Source Engine version 15.