GO What are particle systems used for, in general?

AD Particle systems are used to produce a wide range of effects, everything from weather, through dust and dirt coming from moving vehicles as they interact with terrain, and from small weapons fire to massive explosions and raging fires. Particle systems are used to model almost any kind of smoke, gas or fluid system.

GO Can you give us an idea of how complex the particle system is in Operation Flashpoint*: Dragon Rising? When something explodes, for example, what does the processor have to calculate?

AD When an explosion occurs the CPU has to run two closely linked systems. The first is the game’s Havok* physics engine. This controls the movement and interaction of large objects displaced by the explosion, as well as their deformation and destruction. The second is the particle simulation itself, which involves the creation of several layered particle systems.

GO Were there any innovations or new directions in terms of particle systems in Operation Flashpoint: Dragon Rising?

AD For us there were three key elements we wanted to tackle in Flashpoint. First we developed a flexible and highly efficient CPU-based system to enable us to create a huge number of effects at any one time. Second, we iterated our EGO* GPU solution to allow us to simulate large volumes of wafting smoke across the battlefield without killing the frame rate. Finally, we also built a brand new EGO particle editor, which gave our art teams full control over the final effect in a rapid and iterative manner.

GO How is the particle system processing managed in terms of hyper-threading and multi-core?

AD The particle system runs on a multi-core aware task-based system. This system creates a fixed number of threads based on the number of cores the system has. It can adapt to distribute the active particle effects across the optimal number of threads. The optimal number of threads will vary with the hardware. The EGO used for Operation Flashpoint: Dragon Rising dedicates several threads to fixed jobs, such as feeding the graphics engine and processing the critical game logic. The remaining threads are given to the task manager. On minimum-specification systems the particle system is run on a single thread that’s shared with one of the primary tasks, which is one reason the game really benefits from quad core and above.

GO Are there any other systems in the game that particularly benefit from a fast CPU?

AD A fast CPU is important for many aspects of the game. Operation Flashpoint: Dragon Rising has a great deal of complex artificial intelligence (AI) that needs to be calculated and this benefits from CPU performance. Even graphics benefit from a good CPU, as the game has a large number of individual units that need to be prepared for rendering. Additionally, the CPU uses visibility culling routines to determine exactly what is visible from the players viewpoint. Additional cores help, as many tasks can be split up and processed in parallel.

One particularly intensive task is the path-finding used by the AI to determine how characters and vehicles get from point to point. This task is made more difficult, because the environment can be changed by the player’s actions.

GO Can the player expect to notice a difference running the game on an Intel® Core™ i7?

AD Yes, the Intel Core i7 provides an excellent platform for Operation Flashpoint: Dragon Rising. It offers high performance for critical threads, such as the main game loop, while the EGO engine’s multi-core aware task-based system can use the large number of logical processors on the CPU to offload a significant amount of work from both the render and update threads.