View source for S.T.A.L.K.E.R.: Shadow of Chernobyl

==Technical features==

===X-Ray graphics engine===
{{main|X-Ray (Engine)}}
[[Image:STALKER screenshot.jpg|thumb|right|200px|A screenshot of ''Shadow of Chernobyl'']]
The X-Ray Engine is a DirectX 8.1/9 Shader Model 3.0 graphics engine. Up to a million polygons can be on-screen at any one time. The engine features HDR rendering, Parallax mapping and normal mapping, soft shadows, motion blur, widescreen support, weather effects, and day/night cycles. As with other engines that use deferred shading, the X-Ray Engine does not support anti-aliasing with dynamic lighting enabled. However, a "fake" form of anti-aliasing can be enabled with the static lighting option; this form uses a blurring technique to simulate anti-aliasing.<ref>{{cite web | url=http://www.tweakguides.com/STALKER_5.html | title=Stalker Tweak Guide | author=TweakGuides | publisher=TweakGuides | accessdate=2007-04-03}}</ref> The game takes place in a thirty-square-kilometer area, and both the outside and inside of this area are rendered to the same amount of detail. Some textures in the game were photographs of the walls in the developers' studio.<ref>{{cite journal | year=2004 | month=May | title=PC Gamer UK | issue=135 | pages=38–41}}</ref>

As of patch 1.0003, the X-Ray engine supports "surround screen" monitor setups, including a 16:9 native resolution ratio. A community-developed patch also enables setting a custom field of view and aspect ratio combination.<ref>[http://www.widescreengamingforum.com/forum/viewtopic.php?p=91405#91405 Widescreen Gaming Forum :: View topic - Solution: ''S.T.A.L.K.E.R.'' [Patch&#93;<!-- Bot generated title -->]</ref>

===AI===
[[Image:Ss_benjamin_11-19-08_22-20-49_(l06_rostok).jpg|thumb|left|200px|A screenshot demonstrating the abilities of the X-Ray rendering engine after enabling anti-aliasing and tone mapping.]]
The X-ray engine uses GSC Game World's proprietary A-Life artificial intelligence engine. A-Life supports more than 1,000 characters inhabiting the Zone. These characters are non-scripted, meaning that AI life can be developed even when not in contact with the player.

The [[wikipedia:Non-player character|NPC]]s have a full life cycle (task accomplishment, combat, rest, feeding, and sleep) and the same applies to the many monsters living in the Zone (hunting, attacking Stalkers and other monsters, resting, eating, sleeping). These monsters migrate in large groups. The non-scripted nature of the characters means that there are an unlimited number of random quests. For instance, rescuing Stalkers from danger, destroying Stalker renegades, protecting or attacking Stalker camps, or searching for treasure. The AI characters travel around the entire zone as they see fit.

Numerous tactics can be employed to complete the game, such as rushing or using stealth and sniping. The NPCs will react in a different way to each of them. ''S.T.A.L.K.E.R.''{{'}}s NPCs plan ahead by "Goal-Oriented Action Planning" to achieve this.

===Physics===
''S.T.A.L.K.E.R.: Shadow of Chernobyl'' uses a heavily modified version of the [[wikipedia:Open Dynamics Engine|ODE physics engine]]. [[wikipedia:Ragdoll physics|Ragdoll physics]], destructible objects, realistic bullet ballistics and skeletal animation can all be found in the game.

The game's use of bullet physics is similar in nature to [[wikipedia:Tactical shooter|tactical shooters]] such as ''[[wikipedia:Ghost Recon Advanced Warfighter|Ghost Recon Advanced Warfighter]]'' or ''[[wikipedia:Operation Flashpoint|Operation Flashpoint]]''. Bullets are affected by gravity, bounce against solid surfaces at oblique angles, and firearms are highly inaccurate when fired without aiming. To score consistent hits at medium or long range, players must aim using the [[wikipedia:Iron sights|iron sights]] on their guns. Additionally, hit damage is pseudo-realistic, and the player can die after only being shot a few times (although later in the game various armor suits and artifacts can be acquired that increase the player's resistance to damage). Success late in the game depends heavily on scoped weaponry because of the well-armed and armored enemies who keep their distance from the player. <ref>{{cite web | url=http://gamereviewonly.com/3/stalker-shadow-of-chernobyl/ | title=''S.T.A.L.K.E.R.: Shadow of Chernobyl'' | accessdate=2007-11-28 | author="Game Review Only" | date=2007-11-28 | language=English }}</ref>

===Weather===
A weather system is integrated into various parts of the landscape and allows a variety of weather effects, such as sunshine, storms, and showers. The weapons available, behavior of the AI, game tactics, and ranking systems depend on the weather.