Exclusive: PhysX In Batman: Arkham City - A First Look
October 18, 2011
By Andrew Burnes
Rocksteady Studios accomplished the inconceivable in 2009: they made an excellent superhero game. Batman: Arkham Asylum took the sales charts by storm, racking up several million sales; received heaps of praise from reviewers; and was eventually crowned 'Most Critically Acclaimed Superhero Game Ever' by the Guinness World Records Gamer's Edition reference book. On the PC, Arkham Asylum was one of the first games to make abundant use of Hardware-Accelerated PhysX effects, enhancing background details, incidental items that added to the immersion, and even entire levels (Scarecrow’s nightmare world was particularly memorable). For Batman: Arkham City, developer Rocksteady Studios has gone all out, making the most extensive use of PhysX to date.
PhysX, a real-time physics engine, makes use of the CUDA Cores present within NVIDIA’s graphics cards to calculate physically accurate effects that heighten immersion and realism. While CPUs are capable of providing a baseline level of physical simulation, with GPU acceleration, the scale and accuracy of the simulation is increases dramatically. For example, particles in most games clip through walls and objects to preserve performance. With GPU accelerated physics, up to ten times as many particles can be simulated accurately, allowing them to bounce and collide against the environment and other objects in the scene. Beyond particles, the technology can be used to simulate cloth, destruction and any number of other effects.
Arkham Asylum impressed with its lengthy single-player campaign, excellent story, pitch-perfect voice acting, refined controls and combat system, and its leaderboard-rated Challenge Rooms that added further longevity to a title breaking the trend of ever-shorter, even more expensive games. Now, two years later, we’re less than a month away from the November 15th release of Batman: Arkham City, a direct sequel first hinted at in Arkham Asylum’s secret room.
Taking the action into the eponymous Arkham City, Batman finds himself tracking-down several of the escaped villains who were previously held in the aforementioned asylum, in addition to well-known and obscure enemies from DC Comics’ graphic novels of old. Alongside a lengthier single-player campaign Arkham City also includes hundreds of hidden secrets, more Challenge Rooms, unlockables galore and a more difficult New Game Plus mode, allowing you to replay the entire game with all your gadgets and abilities from the off. To keep things interesting in New Game Plus there are more enemies, combat requires the use of more combos, and all dodge prompts are removed (these prompts are a key component to the combat, letting you know when to block and counter an enemy’s attacks).
Today, we’re releasing the first footage from the PC version of Arkham City, showing the level of graphical fidelity you can expect when running the game using the recommended graphics card, the GeForce GTX 560, with all settings and PhysX enabled:
As you will have seen we also show the game running on the GeForce 8800 GT, which recently celebrated its fourth birthday and continues to be the most popular graphics card amongst Steam’s 35 million gamers (the 9800 and 8800 are one in the same, and combined account for 9.69% of all graphics cards used on Valve’s service). While the overall graphical fidelity is close to that of the GTX 560, the 8800 GT cannot maintain an adequate frame rate with PhysX enabled, nor will it be able to cope with some of the more demanding scenes in the game without suffering from frame rate hiccups.
In the PhysX portion of the video, we start by seeing PhysX-powered bank notes (0:33) reacting realistically to the movement of Catwoman’s whip and the movement of the air around the whip as she attacks enemies; Catwoman herself; the enemies; and the other bank notes. Each note’s movement is calculated and updated every frame by the PhysX engine and the GPU's CUDA Cores, and each remains within the scene after falling to the floor, rather than vanishing to reduce the load on the CPU or GPU as in other games.
In the next scene, 0:41, we see Batman fighting hoodlums in a fully-functional steel mill. On the left of the screen you’ll note a few particles emanating from the furnace, but these are in fact pre-canned animations, looping constantly. On the right, the CUDA Cores generate hundreds of simultaneous particles that bounce off surfaces and collide with the characters, creating the impression that steel really is being created.
A close-up of dynamic particle movement follows in our next scene at 0:45. On the right of the screen, with the assistance of GPU physics, the fire extinguisher now emits a cloud of ‘fog’ that reacts realistically as the thug passes through it. Note also how the fog nearest the camera is pushed out that bit further once the thug stops moving due to the kinetic energy exerted, and the volume of fog behind colliding with the fog at the fore. Contrast this with most of today's games, where smoke or fog rarely interacts with dynamic bodies.
As the thug runs he also causes the papers on the floor to move, and to his left a colleague walks through a doorway, pushing aside thick, heavy strips of a rubbery material, as you might see in a refrigerated area of a warehouse. Both of these effects repurpose PhysX code previously used to realistically render the movement of banners and cloth in Batman: Arkham Asylum and other games, and as in other scenes they are absent when playing Batman: Arkham City without PhysX enabled, as shown on the left of the screen.
Perhaps the most impressive use of PhyX in the video is in the final side-by-side scene at 0:53. Here, Rocksteady goes all-out, showering the area with thousands of Mr. Freeze’s ice particles that bounce off one-another and react realistically to collisions with the floor and walls, and with several uses of the cloth movement effect to manipulate the curtains, drapes and rope barriers.
That one comparison, more than any other, exemplifies how Hardware-Accelerated PhysX effects can add immersion and excitement to a scene, and once you get your hands on Arkham City you’ll discover many other excellent uses of the industry-leading technology and have the opportunity to see first-hand how PhysX can enhance games.
With a graphics card capable of powering the PhysX effects you can also enable a number of other enhancements, chief amongst which is DirectX 11 tessellation. Adding extra detail to objects and scenes, tessellation is one of the hottest new properties in game engine programming and will be the focus of a future Arkham City article that also examines the other enhancements and additions to the PC version of the game.
As a host of reviews attest Batman: Arkham City is an exemplary follow-up to Arkham Asylum, an assessment I fully agree with. Having completed the game in stereoscopic 3D with PhysX and every other setting enabled and maxed out, I can further add that Arkham City on the PC looks absolutely fantastic and is categorically worth the extra wait if you’re interested in playing the preeminent version of one of the year’s best games.
If you need a new graphics card to enjoy the eye candy and enhancements, our preliminary tests show that Batman: Arkham City runs smoothly on a GeForce GTX 560 at 1920x1080 using High Quality presets, just like Battlefield 3. And remember, many e-tailers are bundling a free copy of the game with GeForce GTX 500-Series graphics cards for a limited time, saving you money and allowing you to play Arkham City the moment it is released on November 15th.
For more on Batman: Arkham City check out our game page.