Sneak peak at Far Cry 2 and its use of a multi-core CPU

Posted at: 8:26pm 20th August 2008 by Clive Webster at IDF in San Francisco

Far Cry 2 will definitely use multi-core and CPU-based Havok physics

Today at IDF Intel showed a demo of Far Cry 2, and confirmed that it’s not only incredibly pretty, but is multi-threaded, with AI and CPU-based Havok physics running as separate threads for multi-core CPU. Renee James, Vice President and General Manger of Intel Software and Solutions Group, talked us through the gameplay to explain what was happening.

First off James pointed out the complex and detailed scenary, with grass and other foliage blowing in the wind. The underlying geometry of these objects is created by the CPU, though James didn't say whether the object animations are scripted or dynamic - either way, it's the CPU that calculated the movement. Next she revealed that the clouds of Far Cry 2 are not merely painted onto a skybox texture as with most games, but are actually calculated, again on the CPU.

Explosions in Far Cry 2 tend to smash up the world spectacularly, as the game uses a Havok physics engine, which is run as a separate unit (and therefore as a independent thread) on the CPU. This is unlike Nvidia’s PhysX physics APU which is accelerated on a GeForce GPU. james didn't elaborate whether the havok engine in Far Cry 2 was Havok FX (which was previously only accelerated on GPUs) or another Havok physics engine.


AI in Far Cry 2 is also run as a separate work unit on the CPU, making animals (and we presume enemies, though James only talked about deer as the demo we saw didn’t have combat) react differently and realistically to threats or environmental changes. Advanced AI is important in games with destructible scenery, as NPCs need sufficientlt adept pathfinding skills to navigate the ever-changing layout of the game world.

Intel is obviously keen to push multi-threading applications, whether those applications are games or more mundane software, as the message being repeated again and again during IDF is that Intel will just add more cores rather than significantly ramping up single-core performance. To aid developers in the creation of multi-threaded applications Intel will launch Parallel Studio (a four-tool plug-in for Microsoft’s Visual Studio) in BETA in November. Intel will also be releasing plug-ins for compilers for Nehalem and Larrabee in the near future.

As yet we don’t know how many cores Far Cry 2 will scale across, so we’ll have to wait until it’s released later this year and run our own tests.