STALKER: Shadow of Chernobyl Tweak Guide

[Page 5] In-Game Settings

In this section I provide full descriptions, comparitive screenshots and recommendations for STALKER's in-game settings, allowing you to determine your personal balance between image quality and performance. While I try to note the performance impact of each setting, it is impossible for me to give exact performance impacts (e.g. a 10% rise in FPS) because it all depends on your specific hardware combination and your other game and system-wide settings in combination. Each system is unique in the combination of components it has, so two people with the same graphics card but different CPUs for example may experience very different FPS results in certain scenes. For FPS comparisons of STALKER using various hardware see this STALKER Performance Analysis.

To access the in-game settings start STALKER and on the main menu screen select Options. The various settings available are covered in detail below:

Video

Render: This setting determines the renderer used for generating the game's graphics, and hence has a major impact on the overall visual quality and performance in the game. The options include Static Lighting, Objects Dynamic Lighting, and Full Dynamic Lighting. Screenshot comparisons of all three are provided above, and each is explained further below:

Static Lighting - While STALKER requires a full DirectX9-compatible graphics card to run, selecting this option switches STALKER to DirectX8 rendering mode. In DX8 mode, Dynamic Lighting is completely disabled, as are various special effects such as HDR. Dynamic lighting is the realistic interaction of moving light sources with objects, causing them to cast accurate shadows for example. In DX8 mode, basic Static Lighting is used, which requires far less graphics card power and hence provides much faster performance. This mode is recommended for everyone who cannot get STALKER to run smoothly regardless of anything else they try.

Objects Dynamic Lighting - In this mode, full DirectX9 graphics are used, however dynamic lighting is minimal, restricted only to the way your torchlight reacts with objects. Most objects in the game world will not cast shadows. Certain fixed objects such as trees or buildings will still cast shadows, but these shadows are not dynamically affected by light sources - they are fixed light maps. For example look at a tree as the sun sets; in this mode the shadow remains the same size and shape. In the Full Dynamic Lighting mode (see below) the tree shadow will be more detailed, and will move around and change shape as the sun moves. Note that High Dynamic Range (HDR) lighting will also be enabled automatically and cannot be turned off. This mode is a good balance of performance and image quality, as even without dynamic lighting most of the benefits of DX9 rendering are visible.

Full Dynamic Lighting - In this mode, full DirectX9 rendering is enabled, include major use of dynamic lighting. This can severely reduce performance on lower-end systems, because multiple light sources such as the sun, campfires, torches, etc. will all interact with the environment and cast complex shadows which constantly change as the light sources move. While this is very realistic, in areas with lots of complex objects or NPCs this can cause severe slowdowns. This mode should only be enabled on high-end graphics cards. Note that once again, HDR lighting is enabled by default if this mode is chosen and cannot be disabled.

Importantly, while these lighting modes can affect performance greatly, the impact also depends on the other relevant settings you have enabled. For example whether you've enabled or disable one or more of the Shadow-related settings (Sun Shadows, Grass Shadows, Shadows Quality) can have a major bearing on the impact of dynamic lighting. If you've enabled NPC Flashlights and Dynamic Lighting for example, then at night or in underground areas, if there are multiple NPCs present with torches then this will noticeably reduce FPS. The Lighting Distance setting also affects your FPS when dynamic lighting is enabled in large outdoor areas.

Furthermore, there are a range of advanced variables which can help you to customize the appearance of lighting in the game. For example you can use the r2_gi variable to turn on a more realistic (but FPS-draining) Global Illumination lighting method; you can customize the appearance of HDR using the r2_tonemap_middlegray variable; you can change how glossy surfaces appear under lighting using the r2_gloss_factor variable; and you can add motion blurring by using the r2_mblur command along with the -mblur switch. See the Advanced Tweaking section for more details of all these.

Quality Settings: You can choose from one of four predefined quality settings here (Minimum, Low, Medium, High, Maximum), which in turn will adjust the Advanced graphics settings (covered further below) accordingly. I do not recommend using a preset as you will get much better results customizing the advanced settings individually to suit your own preferences. See the Advanced settings further below for details.

Resolution: This setting allows you to choose the resolution for the game, as shown in pixel width by pixel height. The options shown are restricted to those supported by your particular combination of monitor and graphics card. The higher the resolution chosen, the more detailed the image but the lower the performance of the game. For more details and tips on resolution see this page of my Gamer's Graphics & Display Settings Guide. If you run a widescreen monitor, to get the correct Field of View (FOV) you can use this community-made Widescreen Fix.

Update: As of the 1.0003 Patch there should be proper widescreen support in STALKER without the need to apply any other fixes.

Gamma, Contrast, Brightness: These sliders control the overall brightness and definition of the image on screen. They have no impact on performance so set to suit your taste.

Full Screen: If enabled, runs the game in full screen mode which is recommended for maximum stability. If unticked, the game will run in a window which may improve performance if a low resolution is also chosen. Again, windowed mode is generally not recommended as it can cause problems with Windows resource management. Note that if you want the window to be centered in Windowed mode, you can use the -center_screen switch - see the Advanced Tweaking section for details.

[Advanced]

The following settings are available when you click the Advanced button at the bottom of the screen. It is strongly recommended that you adjust them individually rather than using the 'Quality Settings' preset above.

Vision Distance: This slider determines the maximum viewable distance in the game world. As viewing distance is lowered, FPS rises because less of the game world has to be rendered. As the screenshot comparisons above show, the practical difference between the 100% and 50% points along the slider is insignificant. In fact even at 25% only a barely noticeable reduction in the far distance is discernable. The main visual impact is between the 25% and 0% point on the slider, where at 0% there is a clear drop in visibility. If you're after a few extra FPS with no noticeable drop in image quality, set this slider around the 50% or even 25% mark. Note however that any lower places you at a playing disadvantage since even the use of binoculars won't extend your viewable distance.

Objects Detail: This slider changes the Level of Detail (LOD) on objects in the game world. As the slider is moved to the left, fewer polygons are used to construct these objects, which can improve performance. However the only noticeable difference as this slider is reduced is the level of detail on trees. Trees further away will become generic-looking blobs and lose their detailed branches. This can help improve FPS particularly in large outdoor areas, but whether the reduction in realism is acceptable is up to you to determine. Note that you can further change the LOD level by using the r2_ssa_lod_a and r2_ssa_lod_b commands - see the Advanced Tweaking section.

Grass Density: This slider controls how thick the presence of grass is in outdoor areas. Grass can cause a noticeable drop in FPS while wandering around outdoors, since it is present in many areas. Lowering the slider from the far right to around the 50% mark thins out the grass noticeably, but still leaves relatively realistic coverage for a nice boost in FPS. Further reductions of the slider don't bring as noticeable a reduction in grass coverage, nor much more of a boost in FPS.

Textures Detail: This slider controls the quality of the textures used in the game. Textures are the images which cover the surface of every object in the game world. The further to the right this slider, the more detailed those textures will be. An animated screenshot comparison of the various positions on the slider can be seen by clicking this link: STALKER_Textures.gif (1MB). Aside from the detailing on the chopper, pay attention to the detail on the character's sleeve, and the ground in front of him. The main impact of using more detailed textures is not so much a drop in FPS, but an increase in loading times and stuttering/loading pauses during the game. This is particularly true for those with graphics cards that have less than 256MB of Video RAM. Importantly, if you change this setting, to see its correct impact you need to quit and restart STALKER otherwise no visible change will occur.

Anisotropic Filtering: Anisotropic Filtering (AF) is explained in more detail on this page of my Gamer's Graphics & Display Settings Guide. Essentially it is a method of making textures sharper as they recede into the distance. This slider controls the sample rate of AF used, up to 16x AF. Most recent graphics cards can enable a reasonable level of AF, such as 2x or 4x, which provides a good level of image quality without any real drop in FPS. However it appears the AF slider doesn't have any significant noticeable impact on the image quality in the game, even when set to the far right. It appears this feature may be broken in STALKER. You can however use the r1_tf_mipbias or r2_tf_mipbias variable (depending on which renderer you're using) to increase texture clarity - see the Advanced Tweaking section.

Antialiasing: Antialiasing (AA) is a method of reducing the jaggedness of lines in 3D graphics. It is explained in more detail on this page of my Gamer's Graphics & Display Settings Guide. However STALKER's game engine uses a form of rendering called Deferred Shading. This effectively means it cannot support proper Antialiasing which would remove all the jagged outlines in the game world, regardless of which type of graphics card you have. Thus the Antialiasing slider has no real impact on performance or image quality, and also cannot be forced on using the graphics card control panel. You can instead use the r2_aa command, and related commands, to enable and customize a fake form of blurred AA - see the Advanced Tweaking section for details.

Update: It appears that as of the most recent Nvidia Forceware drivers that you can force standard Antialiasing in STALKER through the graphics card control panel. This will reduce jaggedness, primarily on terrain and buildings rather than the foliage, however it can come at a very high cost in performance, especially at anything above 2xAA.

The next page continues the descriptions of STALKER's In-Game Settings.