Graphics Changes in Update 9.9

Tank Commanders,

In Update 9.9, the graphic part of World of Tanks was extensively upgraded. Methods of anti-aliasing were updated, shadows were significantly modified, and lighting improved and game client performance streamlined. Great attention was also paid to the overall stability of image – now you’ll see less “twinkling” in various post-effects (HDR Bloom, HBAO, RO, etc.).

. This article describes the implemented changes and clearly demonstrates the image quality progress.

New Anti-Aliasing

With version 9.9, a new method of full-screen anti-aliasing was introduced into the game— Temporal Super Sampling Anti-Aliasing (TSSAA).

Anti-Aliasing is a technique used to remove the aliasing effect on edges of objects.

Of all anti-aliasing techniques, TSSAA can be distinguished for excellent quality and general stabilization of images. It removes visual noise and pixels vibration on thin objects, as well as twinkling of glossing surfaces during movement.

Unlike FXAA, which is already used in World of Tanks, TSSAA is a highly efficient temporal method that applies anti-aliasing not only to the current frame, but also to some frames that were rendered before, restoring old positions of pixels by using their velocity. This allows the creation of smoother and more cinematic images in the game, with just a slight increase in the load on the video card.

Unlike TXAA, TSSAA is not confined to a particular manufacturer and works for the entire spectrum of video cards that support improved graphics.

These are the qualities for which TSSAA is considered to be the best choice for game industry. For version 9.9 TSSAA was written from scratch for version 9.9 to adapt it to BigWorld engine modification used in World of Tanks.  

The TSSA algorithm will be available in two variants:

• TSSAA-LQ is a lighter variant of the new anti-aliasing method; fewer previous frames are used during image processing.
• TSSAA-HQ is the highest quality anti-aliasing method.

Currently, research is being carried out to improve the reconstruction precision and, consequently, to sharpen images when seen from a distance.

New Shadows

Update 9.9 brought thoroughly revised shadows. This resulted in higher quality and strongly reduced load on the processor and video card.

• With the new algorithm, you do not have to calculate shadows from static objects for every frame over and over. What is also nice about this approach is that you get “soft shadows” without creating any external load on the computer. The feature is called Variable Penumbrasoft Shadow (a realistic optical effect of shadow blurring, occurring as the distance from the source object increases).
• Shadows from dynamic objects became much lighter and also feature “soft shadows” at maximum settings.
• Contact Shadows, or Ambient Occlusion, were improved, too. Previously, they were reproduced by the Horizon-Based Ambient Occlusion (HBAO) algorithm in the game. For 9.9 algorithm HBAO was rewritten and streamlined, which increased quality and temporal stability.
• For medium settings, HBAO was replaced with a simpler, but immensely quick and high-quality Screen Space Ambient Occlusion (SSAO) algorithm, which contributed to better performance.

This picture illustrates the optical effect of increasing blurring of shadows with increasing distance to the source of the shadow: on the right of the photo there are visible blurred, soft shadows of the tree, while the shadow of a tank is more contrast because the object - the source of the shadow is closer.

New Lighting Effects

The Bidirectional Reflectance Distribution Function (BRDF) was improved, too. It is responsible for the way the light is reflected at different angles, or absorbed by the surface depending on its roughness (micro-relief). The new lighting model is known as GGX (Microfacet BRDF with a GGX distribution). Being a cutting-edge real-time rendering technology, it ensures the best physical accuracy. Changes in lighting model enable more realistic simulation of a wider range of materials and will be particularly salient on tank models that were redesigned into HD quality.

For the new lighting model BRDF was written algorithm RO (Reflection Occlusion) required to remove artifacts that arise when reflected light passes through opaque objects. Put it crudely, Reflection Occlusion removes light reflection from places where they should not be.

Bloom has become much more stable, at the maximum of post-processing.

Other Optimizations

Besides optimized shadow calculations, Update 9.9 will also introduce numerous system optimizations in the graphic engine. This improved the graphics and reduced the load on the processor when creating static objects, trees, and effects.

Update 9.9 also features redesigned switching of graphic settings, reconfigured pre-settings, and a simpler scheme for creating fog and bloom.