The original Starcraft engine, though much adored, was mostly 2D and supported a maximum resolution of 640 x 480. When it was being developed, 3D graphics was still in its infancy—3dfx had just launched the Voodoo. DirectX had barely reached version 5.
For a game with such an illustrious history, the team at Blizzard wanted to make sure that Starcraft II’s graphics engine would utilize all the graphical enhancements that had evolved over the last decade.
Unlike typical graphics engines which have a singular focus, Starcraft II's engine serves two distinct purposes. First, it provide the top down view for directing a large number of units on the battlefield. Second, it provides a first-person view for high quality in-game cut scenes. In order to satisfy both scenarios, Starcraft II's engine incorporates a variety of modern rendering techniques.
A full-fledged battle in Starcraft II may have over hundreds of units on-screen at a given time. When one unit fires, its generates a light that affects nearby units. When hundreds of units fire, most engines grind to a halt as they try to compute how hundreds of lights affect hundreds of units. To enable a large number of dynamic lights, Starcraft II uses a deferred lighting engine. Unlike traditional engines which require perform lighting calculations on every pixel—whether visible or not—deferred lighting waits until all pixels are deemed visible, then performs the lighting calculation. The result is that a much large number of lights can be used in a given scene. When dozens of marines are firing, tanks are shelling from behind, and Battlecruisers are discharging their Yamato cannons, the combined lighting from these units are made possible thanks to the deferred lighting engine.
High-quality in-game cut scenes form the backbone of Starcraft II's storytelling. To adopt an RTS engine for close-up view, Blizzard authored highly detailed models of key characters and incorporated a sophisticated depth-of-field shader. The depth-of-field shader allows the game designer to selectively blur the background or foreground, drawing the attention of the player to key characters in the same way the director changes the focus of the camera in a movie scene. The result is that every mission has its own in-game cut-scene sequence, making the single-player campaign highly engaging.
Antialiasing for GeForce Users
One of the drawbacks of deferred lighting engines is that it's difficult to support antialiasing. In a game where total mental concentration is required, jaggies are the last annoyance a player needs. Thankfully, GeForce drivers can provide antialiasing even if the game doesn't natively support it. To play Starcraft II with antialiasing, install the latest graphics driver, right click on the desktop to reach NVIDIA's Control Panel, then set antialiasing to override the application.
With the v1.1 patch, Blizzard added official support for NVIDIA 3D Vision to Starcraft II. 3D Vision adds even more depth and immersion to Starcraft II's gameplay.
In 3D mode, the command console floats on top of the 3D scene, giving the impression that one is commanding the battle from a vantage point. Flying units such as Battlecruisers and Carriers appear much closer to the camera than ground units such as Marines and Zealots. When viewing major battles zoomed-in, the various units have an amazing sense of perspective and scale. A group of stacked Mutalisks—the bane of the Terran commander, becomes easier to pick apart.