Bringing GameWorks Out of the Shadows with HBAO+

by Monier Maher

Photographers and moviemakers know it’s critical. Game designers do, too. Shadowing is a critical component of the visual arts, including video games.

Lighting and shadows add depth to a scene, drastically raising image quality. They can be an important part of game play, like the shadows you hide in while playing in Tom Clancy’s Splinter Cell Blacklist, or a key part of setting a mood, like in the horror game Daylight.

Shadowing helps Paris come to life in Assassin’s Creed Unity. And it makes the Dark Knight more ominous in Batman: Arkham Origins.

It took just an hour to add NVIDIA HBAO+ to Warmachine: Tactics.

That’s why NVIDIA HBAO+ has quickly gained traction in the development community. The most recent example of a game using HBAO+ is Son of Nor. Launched this week at the Game Developers Conference in San Francisco, it’s the first Unity Engine-based game to feature HBAO+.

What is HBAO+?

HBAO+ is an advanced form of ambient occlusion; a technique used in film production to approximate the effect of environment lighting. Unlike the dull, flat look of local lighting models, ambient occlusion can add realism to a scene by accentuating small surface details and adding soft shadows.

Screen space ambient occlusion (SSAO) is the most commonly used method for rendering of AO effects in games. It approximates ambient occlusion by using the depth buffer to approximate the geometry in the scene.

What does HBAO+ look like? In this image, each shaded pixel comes thanks to HBAO+. Without Ambient Occlusion all you would see, with the exception of the fire effect, is a white screen.
What does HBAO+ look like? In this image, each shaded pixel comes thanks to HBAO+. Without ambient occlusion all you would see, with the exception of the fire effect, is a white screen.

NVIDIA’s HBAO+ is the most advanced form of SSAO, providing significantly higher quality and less visual artifacts, for less cost in terms of performance.

Because it’s middleware, HBAO+ is easy for developers to add to their games. NVIDIA has worked closely with Epic Games to make integration into games that use their popular Unreal Engine a snap through the GitHub code repository. (See NVIDIA Opens PhysX Code to UE4 Developers.)

WhiteMoon Dreams said it took about an hour to add it to their Unreal Engine 4 title Warmachine: Tactics.

HBAO+ works on GPUs from NVIDIA and its competitors and can be easily integrated into any major game engine. It has been used in games built with CryEngine, Dunia 2, IwGame Engine, Source, Unreal Engine 3, Unreal Engine 4 and many proprietary game engines. A full list of titles that use HBAO+ can be found here.

NVIDIA HBAO+ now enhances World of Warcraft: Warlord of Draenor.

Recently, big name titles have used HBAO+ to upgrade graphics to games that have already shipped. Just last week World of Warcraft upgraded image quality by releasing a patch that included HBAO+ support for gamers to enjoy. The patch updated the render, so HBAO+ was added to the latest expansion, World of Warcraft: Warlord of Draenor, and previous expansions such as Mists of Pandaria and Cataclysm.

So now that you know what HBAO is, look for more of it in upcoming games, as well as updates to old favorites.

More coverage of our announcements at GDC: Latest PhysX Source Code Now Available on GitHub, New NVIDIA Titan X GPU Powers Virtual Experience “Thief in the Shadows” at GDC, Why We’re Building SHIELD, the World’s First Android TV Console.