Earlier today at GamesCom in Cologne, Germany, NVIDIA and Ubisoft announced the signing of a far-reaching technology agreement that will see the two firms bolster Ubisoft’s upcoming AAA PC games with advanced features, effects and technologies that make the most of GPUs like the GeForce GTX 780. The first game to benefit from this unprecedented relationship is Tom Clancy’s Splinter Cell Blacklist, which is launching worldwide this week with full support for NVIDIA TXAA Anti-Aliasing, NVIDIA HBAO+, and NVIDIA SLI, the smoothest and fastest multi-GPU solution available.
For those new to the long-running Splinter Cell franchise, Blacklist
casts you as series protagonist Sam Fisher, one of the world’s most
skilled covert operatives, tasked with the most challenging missions in
the world’s most dangerous hotspots. Using stealth, gadgets, and the
occasional overt action, Sam must sneak his way to the truth about a new
terrorist plot, and ultimately save the day before the United States of
America is consumed by terrorism. When you’ve saved the day, you can
jump into intense co-op missions, and a much-anticipated 4v4 multiplayer
mode that pits Sam-style stealth agents against gun-toting operatives
who desperately defend important objectives.
On all formats Blacklist looks lovely, but on PC there is a ton of extra tech for your PC to tackle.
NVIDIA HBAO+ Ambient Occlusion
Splinter Cell is a franchise dominated by shadows. Sam does his best
work when under their protection, sneaking, snapping necks, and
circumventing security systems, so it is imperative shadows are as
detailed and realistic as possible. The PC version of Blacklist features
higher-resolution, more detailed shadows, as you would expect, but to
take the PC version to the next level something new was required. To
that end, NVIDIA and Ubisoft have worked in concert to implement a brand
new shadowing effect called HBAO+, which makes its debut this week in
the critically-acclaimed Splinter Cell Blacklist.
An important advancement in the field of Ambient Occlusion (AO)
shadowing, HBAO+ dramatically improves upon existing AO techniques to
add richer, more detailed, more realistic shadows around objects that
occlude rays of light. In comparison to previous techniques (such as
the “SSAO+” technique available in Blacklist), HBAO+ doubles the overall
number of samples per pixel, runs twice as fast, and uses the latest DirectX 11 technologies.
The world of Blacklist is full of shadows, demanding new, cutting-edge shadow tech.
Most commonly, games use Screen Space Ambient Occlusion (SSAO) for
the rendering of AO effects. There are many variants, though all are
based on early AO tech, and as such suffer from a lack of shadow
definition and quality, resulting in a minimal increase in image quality
(IQ) compared to the same scene without AO.
At the 2008 SIGGRAPH tech conference NVIDIA introduced an upgraded SSAO variant called Horizon Based Ambient Occlusion
(HBAO). Unlike previous SSAO variants, HBAO uses a physically-based
algorithm that approximates an integral with depth buffer sampling. In
other words, the upgrade enables HBAO to generate higher-quality SSAO,
whilst increasing the definition, quality, and visibility of the AO
shadowing.
For performance reasons, however, HBAO is typically rendered at half-resolution, as in Battlefield: Bad Company 2 and Battlefield 3,
reducing the number of AO pixels by three-quarters. Unfortunately,
rendering HBAO at reduced resolutions inevitably causes flickering that
is challenging to hide in all situations – Battlefield 3 HBAO selective
temporal filtering helps, but in some cases flickering persists.
To overcome these issues, NVIDIA’s Louis Bavoil has completely
redeveloped and revamped Screen Space Ambient Occlusion to create HBAO+,
a paradigm shift in the field of Screen Space Ambient Occlusion
rendering.
Shadowing has come a long way since the release of the original Splinter Cell, a decade ago.
The first goal for Louis at the outset of his work was to create an
AO technique that could be rendered at full resolution at 1920x1200 on a
modern GPU like the GeForce GTX 660. HBAO offered good definition at
full resolution, but its crippling performance impact made it
impractical for modern games, and when it was used at a reduced
resolution it still had a heavy impact on frame rates in comparison to
SSAO.
Louis’s second goal was to maximize the efficiency of the AO
implementation by leveraging the speedy DirectX 11 tech on GPUs, and the
software advances that DX11 brought to the table when launched in 2009.
Ultimately, the new DirectX 11 hardware and software enabled Louis to
render HBAO+ with a fast Interleaved Rendering
technique instead of a slow Fullscreen Pass, which had to be further
supplemented by per-pixel jittering for the reduction of aliasing on AO
shadows.
Louis’s third and final goal was to improve the visual fidelity of
HBAO+ in comparison to HBAO, especially in scenes with grass, leaves,
and other fine detail. As seen in Far Cry 3, HBAO struggled in such
situations, creating overbearing, solid areas of shadowing.
HBAO+ is as-important when outside, helping to create a realistic scene lit by the sun and man-made lights.
The result of Louis’s work is a more accurate Ambient Occlusion
technique, with weighty shadows that are better defined, more accurate,
and more visible. Below, you can view an interactive comparison that
shows a scene with all textures and game elements removed, leaving only
the Ambient Occlusion shadowing, enabling an easy comparison between the
new and old techniques.
Note how the HBAO+ Ambient Occlusion shadowing is far more accurate,
sitting correctly on and around objects in a non-uniform fashion. Also
note the fence-like area towards the rear of the image. With HBAO, the
technique’s poor sampling quality results in the area being uniformly
shadowed, similar to the grass situation in Far Cry 3. In this demo, on a
GTX 680 at 1920x1200, HBAO+ is over three times faster than HBAO,
dramat
In Blacklist, Ubisoft’s full-resolution SSAO+ technique offers
superior image quality in comparison to half-resolution SSAO, but
seriously impacts the frame rate in the process, running 3.3
milliseconds per frame slower. HBAO’s implementation, meanwhile, runs at
full-resolution but with only 4 occlusion samples per pixel, far fewer
than the 16 used for SSAO and SSAO+. The trade-off is an increase in
performance and an AO’d image with its own, separate set of issues.
Full-resolution NVIDIA HBAO+, in comparison, is nearly twice as fast
as the next-best Blacklist AO technique, SSAO+, and achieves this feat
with more than double the number of occlusion samples. The result is a
speedy implementation that offers a far richer, more detailed image than
the other techniques.
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