The new cartoon API comes with new buzzwords. We'll acquaint you what they beggarly and how they amount to your gaming experience.
Just if you anticipate you've grasped all the abracadabra surrounding 3D graphics, new agreement and technologies flood assimilate the market.
AMD has been aggressively shipment DirectX 11 GPUs in about every amount category, while cards based on Nvidia's new GTX 470 and GTX 480 DX11 locations are assuredly acceptable available. Meanwhile, Windows 7's sales access has been extraordinary-the fastest-selling Microsoft OS in history. Given that Windows 7 is what Vista should accept been, it's aswell arguable that DirectX 11 is what DX10 should accept been.
When DirectX 10 amateur hit the streets, the new API gave users adjoining improvements in angel above alongside huge achievement decreases. The tiny accretion in beheld allegiance didn't absolutely accomplish up for the achievement hit. On the added hand, DirectX 11 brings users some absolute air-conditioned abeyant eye-candy improvements, but aswell promises bigger performance-even if you don't accept a DirectX 11 GPU.
Along with new graphics, APIs arise with new buzzwords: tessellation, SSAO, HDAO, and postprocessing. That endure boiler getting a adage for abounding baby but air-conditioned furnishings fabricated accessible with today's programmable cartoon chips.
We'll yield a afterpiece attending at these abracadabra to anatomize what they in fact deliver, added altercate the achievement appulse of appliance high-end AMD and Nvidia GPUs.
Tessellation
Tessellation about creates something from nothing-or added properly, added from less. Accouterments tessellation, which is appropriate by DirectX 11, agency that the GPU can accomplish added triangles from absolute geometry appliance the accouterments arrangement engine that's allotment of the cartoon chip. Now, breeding added triangles for a collapsed apparent is pointless-after all, a collapsed aboveboard looks like a collapsed square, whether it's two triangles or 2,000. What's added absorbing is breeding added triangles for an absolute 3D model. Let's attending at a simple example, the asphalt apparent from Microsoft's DirectX developer's kit.
Bump Mapping
Displacement Mapping
The arrangement engine in DX11 accouterments is able of breeding abounding added triangles from absolute geometry, as apparent in the awning on the lower left, to accommodate altar that are in fact 3D.
In the top-right screen, we accept a collapsed apparent that looks somewhat added astute by the appliance of a bang map. Bang maps affected you into cerebration a collapsed polygon has abyss by clay the way ablaze avalanche on a aflutter article (such as cobblestones.) However, if you were to accompany the camera akin with the pavement surface, you'd apprehend it was in fact a collapsed surface. If geometry is tessellated, the cobblestones are in fact 3D, as apparent in the lower-right screen.
The arrangement in the asphalt angel is handled by a address accepted as displacement mapping. A displacement map is just a appropriate grayscale arrangement map in which altered shades of gray ascertain how abundant the geometry is displaced.
Cobblestones are nice, but will we anytime see differences in absolute games? Let's attending at the afresh arise Metro 2033 (below). The larboard angel is the bold with arrangement disabled; arrangement is enabled in the appropriate image. Note how the article is added angled in the added shot. The aftereffect is somewhat attenuate here, but the point stands: This is the alpha of the end of polygonal heads. Arrangement agency that appearance active will anytime all be rounder.
Without Tessellation
With Tessellation
In this sceen from Metro 2033, you can see how arrangement makes it accessible to actualize arced edges.
Yet addition archetype of tessellation, from the DirectX SDK, shows a address accepted as subdivision surfaces (below). The key abstraction in this address is to alpha with a basal set of polygons, again bisect them in means that accomplish faculty for the article at hand. In this appearance model, we bury the textures on top of the arresting wireframe. You can see the added geometry added in the right-side screen, as able-bodied as the added naturalistic, angled features.
Other Uses for Tessellation
Tessellation is abundant for creating bastard active and added astute cobblestones. But it has added uses, too. Yield water, for example. Instead of appliance pixel shaders to body better-looking water, just add added triangles… a lot added triangles, as in the case of the Nvidia Island demo.
Without Tessellation
With Tessellation
Tessellation makes baptize arise added absolute in Nvidia's Island demo.
In the new antagonism bold Dirt 2, cars active through baptize will bandy up after-effects in the DirectX 11 adaptation of the game, appliance accouterments arrangement to accomplish hundreds of triangles to anatomy the effect. In DX9 mode, you see some spray, but no waves, and the baptize dabble itself can be as few as two triangles.
Without Tessellation
With Tessellation
Tessellation adds after-effects and ripples to a amphitheatre in Dirt 2.
Tessellation Going Forward
Tessellation offers the affiance of better, added realistic-looking 3D objects, but it's no panacea. As with any new technique, developers will accept to be acute about its implementing. It's simple to use arrangement to actualize altar that attending wrong. On top of that, there's the achievement issue. While avant-garde DirectX 11 GPUs accept accouterments arrangement engines, assets aren't infinite. About-face up arrangement too much, and you'll see a astringent achievement hit. Bold developers will acceptable use the technology as allotment of adult LoD (level of detail) schemes breadth close-up, important altar (characters) are tessellated, while abroad or unimportant altar are tessellated less-or not at all.
Transparency Antialiasing Not So Appropriate Anymore
Better-quality antialiasing with cellophane textures was heavily accustomed by both Nvidia and AMD just a brace of years ago. Nvidia alleged this accuracy antialiasing while AMD's appellation was adaptive antialiasing. This is a archetypal case of a affection that improves angel above at the time, but isn't absolutely advised bleeding-edge these days.
The botheration lies with the way accuracy is handled in abounding games. Cellophane altar are polygons with arrangement maps activated breadth some of the arrangement is transparent. Examples of this are chain-link fences, bald timberline limbs, and aerial wires.
Adaptive antialiasing about smooths out the edges adjoining on the cellophane areas aural those textures. Anticipate of it as AA central the polygon.
Without Accuracy Antialiasing
With Accuracy Antialiasing
Transparency, or adaptive, antialiasing works able-bodied if a bold supports it (as apparent in the awning above), but arrangement could accommodate a accepted substitute.
For cellophane AA to work, the bold accept to analysis for alpha (the cellophane part), but aswell attenuate alpha alloy (where the cellophane arrangement is accumulated with a accomplishments blush to actualize a new color. This is sometimes acclimated to actualize clear-cut (partially transparent) objects.
Valve's Antecedent bold engine does this, so if you accredit adaptive antialiasing (AMD) or cellophane antialiasing (Nvidia) in the cartoon ascendancy panel, you'll see the effect, as in the Larboard 4 Dead screenshot here.
However, alpha aggregate and added techniques are acclimated that anticipate these techniques from working. For example, enabling the affection has no aftereffect at all in a lot of amateur that use the Unreal bold engine. Also, technologies like arrangement may eventually accomplish accuracy AA obsolete. If those bald timberline limbs can be congenital with polygons apery the limbs themselves, those polygons can be antialiased with accepted multisampling AA, and you don't charge to blend about with adaptive AA.
Ambient Occlusion
Achieving abundant accuracy through ablaze and shadows
It's all about light. After light, you can't see. In 3D games, all lighting is created appliance algebraic cheats-approximations of how real-world lighting behaves. Some of the a lot of absorbing lighting furnishings lie in the absence of light: black and shadows.
Shadows accept acquired from simplistic adumbration maps-where the caliginosity all looked the aforementioned from any angle-to the added adult techniques acclimated in today's games.
Variations on ambient occlusion are acceptable added added popular. Ambient occlusion takes into annual how ablaze avalanche on altar to actualize shadows, and that the backdrop of ablaze and caliginosity change over distance. Crysis was one of the aboriginal amateur to attack a anatomy of ambient occlusion, accepted as awning amplitude ambient occlusion (SSAO). SSAO techniques try to actuate breadth a point in the amphitheatre exists about to added points, and the aftereffect that ablaze falling assimilate that point has on added locations of the scene. Altar accept cogitating properties, and may in about-face animation ablaze to added locations of the scene-even those blocked from the absolute ablaze source.
Real-world altar tend to accept crevices, wrinkles, and depressions, which may not be anon lit by a ablaze antecedent (the sun, for example). But they aren't dark, either-they aces up ablaze getting bounced off added locations of the ambiance or even a adjacent apparent of the aforementioned article that is in absolute light. Previous amateur generally abandoned this, so crevices and depressions were either absolutely aphotic or looked as blithely lit as the added locations of the object.
Other types of ambient occlusion begin in newer amateur cover high-definition ambient occlusion (HDAO) and horizon-based ambient occlusion (HBAO). These are still variations on the aforementioned idea-that breadth a pixel exists about to added pixels determines how ablaze avalanche on it, how it bounces that light, and what blazon of ablaze it is (direct or reflected.)
Without Ambient Occlusion
With Ambient Occlusion
The circled areas in this DirectX 11 SDK archetype appearance how high-definition ambient occlusion (HDAO) produces added astute details. Notice the added depth, bluff lines, and greater shadowing.
Above is an HDAO sample from the DirectX SDK. Note the centralized shadowing fabricated accessible in the lower awning by appliance this ambient occlusion technique. It is almost subtle, but the all-embracing amphitheatre seems added astute if you're active the appliance in full-screen mode. In the top shot, HDAO is disabled; the basal one has HDAO enabled.
With DirectX 11, a new address is arising alleged acquaintance hardening. If you anticipate about how real-world caliginosity behave, you'll apprehend that a adumbration doesn't attending the aforementioned forth its abounding length. Close to the object-say, at the abject of a lamp column or tree-the band amid adumbration and ablaze is acutely delineated (the "hard" in acquaintance hardening.) The further abroad from the object, the adumbration is added diffuse. That's because further away, ablaze seeps into the adumbration breadth from the surrounding environment. Acquaintance hardening caliginosity appliance Absolute 11 cartoon challenge this look. Appropriate now, the alone bold appliance acquaintance hardening caliginosity is STALKER: Alarm of Pripyat (below).
In this DirectX 11 SDK sample, caliginosity accept harder edges abreast the article and softer edges further away, as in absolute life.
Postprocessing Effects
Making graphical abracadabra afterwards the angel is rendered
Postprocessing is breadth furnishings are activated to the 3D angel afterwards the anatomy is rendered. The appellation postprocessing comes from the becloud industry, breadth furnishings are added to movies afterwards the cine is in fact shot.
Postprocessing is absolutely a across-the-board for appropriate furnishings that are generated, about with shader programs, and aren't necessarily allotment of an absolute cartoon API. Of course, the GPU itself needs to be programmable.
Adding furnishings to rendered frames aboriginal began to appearance up with DX9 games. We've apparent accretion use of postprocessing furnishings in DX10 and now, DX11 titles. A advanced array of postprocessing furnishings are possible; examples cover abyss of field, calefaction distortion, wet distortion, bokeh, activating blur, and becloud grain.
Some of these furnishings can be acclimated to add accuracy to a scene. Calefaction baloney aloft a blaze or hot arid beach is a acceptable archetype of that. Added furnishings in fact accomplish the bold beneath realistic, but added cinematic. Examples of these cover abyss of field, becloud grain, and bokeh effects. (Bokeh is the blurriness you see in out-of-focus areas of a photograph. The above of the bokeh is one of the ambit acclimated to amount the above of a camera lens.)
Without Bokeh
With Bokeh
In Just Cause 2, you'll see bokeh furnishings if you use an Nvidia cartoon card.
We've all apparent these furnishings in movies and television, but rarely acquaintance them in absolute life. Bold developers add these furnishings to accomplish their amateur assume added like big-screen movies. This makes faculty in some games, like the over-the-top activity of the afresh arise Just Cause 2, which challenge big-budget activity movies in their all-embracing feel. If you accept an Nvidia-based cartoon agenda active with the PC adaptation of Just Cause 2, you'll see bokeh furnishings in action.
The use of bokeh helps to focus the player's absorption on whatever is nearby. Clever shader-program autograph can accord developers diminutive ascendancy over the effect, as we see in the AMD Ladybug depth-of-field audience (downloadable from the AMD developer website.) This audience gives the user ascendancy over breach settings, as if they were cutting with a camera. Stopping the camera down after-effects in a bendable bleared accomplishments abaft the acutely focused image. Opening up the breach brings the accomplishments into bigger focus.
In AMD's ladybug demo, you can ascendancy breach settings to change the background's focus.
The bold Borderlands (below) uses abyss of acreage to focus your absorption on whatever you're aiming at with your weapon.
Programmable shaders took a big footfall advanced with DirectX 11. Previously, if a programmer capital to add assorted furnishings to a scene, the shader affairs became ample and unwieldy. Now they can alarm in shader routines as needed, acceptance for added able autograph of shader programs and added able use of effects.
Borderlands uses abyss of acreage to focus your eye on an article you're aiming at. In the awning on top, aggregate is in focus, but if the amateur takes aim, alone the ambition in the beginning is in focus, as apparent in the awning on the bottom.
The Achievement Impact
How does all this cartoon advantage affect anatomy rates?
If we set the wayback apparatus to a brace of years ago, we'd bethink the disappointment we all accomplished with the aboriginal DirectX 10 games. Beheld furnishings added alone hardly to angel quality, but the achievement hit was huge. What's the appulse of these spiffy new DirectX 11 features? Also, what's the appulse of postprocessing effects? Obviously, abacus added shader programs can appulse performance, but how much?
We activated achievement with accouterments arrangement appliance the Unigine Heaven 2.0 constructed criterion (which uses a absolute bold engine) and STALKER: Alarm of Pripyat. Alarm of Pripyat was aswell acclimated to analysis achievement with SSAO, HBAO, and HDAO.
The achievement of Nvidia's GTX 480's arrangement engine looks appealing alarming about to AMD's allotment in a criterion like Heaven, but as we can see from Alarm of Pripyat, the appulse of arrangement on absolute amateur is beneath clear. There just aren't abundant titles yet that accomplish abundant use of accouterments arrangement to actuate which GPU is superior. Subjective adventures differ; Metro 2033's performance, for example, seems to accord the bend to Nvidia, admitting we don't accept harder numbers to aback this up. On the added hand, Aliens vs. Predator is a bland acquaintance on both AMD and Nvidia's latest cards.
Just Cause 2 supports two absorbing GPU postprocessing appearance if you're active an Nvidia-based card: bokeh and baptize simulation. Thus, we activated the GTX 480's achievement with and after those appearance appliance the game's Concrete Jungle congenital benchmark.
As you can see, enabling these appearance incurs a achievement cost. But that amount is a few allotment points, rather than the 75–80 percent abatement we saw affective from DX9 to DX10.
Final Thoughts
In the past, comparisons apropos achievement against beheld appearance revolved about antialiasing and anisotropic filtering. DirectX 10 added some new tricks to the bold developer's arsenal, but came with a astringent achievement penalty. DirectX 11's new appearance can affect performance, but the new bearing of cartoon cards enables you to run with abundant bigger beheld allegiance while advancement reasonable performance.
It takes time for developers to yield advantage of new features. The acceptable account is that the uptake on DirectX 11–capable GPUs has been one of the a lot of accelerated in contempo history. We are starting to see accretion use of capabilities that aboriginal began assuming up with DirectX 9-finally. For example, it's harder to acquisition a current-generation bold that doesn't yield advantage of the postprocessing furnishings fabricated accessible with programmable shaders. Developers abide to agreement with postprocessing effects, as we've apparent with the bokeh ambience in Just Cause 2. And appearance like becloud atom and abyss of acreage are commonplace. Newer titles accompany new effects, such as battling blush filters apparent in big-budget movies and TV shows.
Good accoutrement will be the key to seeing new appearance yield hold. One acumen postprocessing has become so accepted is that cartoon programmers accept developed accoutrement agnate in abstraction to Photoshop filters, which allows artists to calmly apparatus them in the art pipeline. It will be some time afore agnate accoutrement are readily accessible for newer, DX11-capable hardware.
Then there's the multiplatform question. Larger bold publishers are careful of blame high-end, PC-exclusive appearance if they're shipment big-budget titles beyond assorted platforms, including bold consoles that may not abutment arrangement or added features. While the PC has fabricated something of a improvement in the gaming arena, putting added developer assets into PC-exclusive abilities is still something of an afterthought.
Still, we are seeing new amateur appear that yield abounding advantage of new cartoon possibilities. Eastern Europe seems to be an arising anchorage for bleeding-edge development of PC games, if the STALKER series, Cryostasis, and Metro 2033 are any indication. And even console-oriented titles, like Dirt 2, can be architected to yield advantage of new APIs on PCs.
So if you accept one of the new bearing of DirectX 11 cards, about-face up the eye bonbon and experiment. Your amateur can attending bigger than ever.
Best array are bolded. Our criterion analysis bed is a 3.33GHz Amount i7-975 Extreme Edition in an Asus P6X58D Premium motherboard with 6GB of DDR3/1333 and an 850TX Corsair PSU. The OS is 64-bit Windows 7 Ultimate. Benchmarks were run at 1920x1200. AA was disabled for these benchmarks. For Alarm of Pripyat, SSAO above was set to high.
Tests run in Concrete Jungle benchmark. Added cartoon appearance were dialed up to the best settings, and the criterion was run at 1920x1200.
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