Flight Unlimited is a 1995 aerobatic flight simulation video game developed and published by LookingGlass Technologies. It allows players to pilot reproductions of real-world aircraft and to perform aerobatic maneuvers. They may fly freely, race through floating rings against a timer or take lessons from a virtual flight instructor. The instructor teaches basic and advanced techniques, ranging from rudder turns to maneuvers such as the tailslide, Lomcovák and Immelmann turn.
Flight Unlimited was the first self-published game released by Looking Glass Technologies. It was intended to establish the company as a video game publisher and to compete with flight simulator franchises such as Microsoft Flight Simulator. Project leader Seamus Blackley, a particle physicist and amateur pilot, conceived the game in 1992. He felt that other flight simulators failed to convey the experience of real flight, and he reacted by coding a simulated atmosphere for Flight Unlimited based on real-time computational fluid dynamics. Aerobatic pilot Michael Goulian endorsed the game and assisted the team in making it more true to life.
Flight Unlimited received positive reviews from critics and was a commercial success; its sales exceeded 780,000 copies by 2002. Reviewers lauded its realism, flight instruction, graphics and sense of flight, but some criticized its high system requirements. The game was followed by two sequels: Flight Unlimited II (1997) and Flight Unlimited III (1999). A combat-oriented successor, Flight Combat, was released in 2002 as Jane's Attack Squadron after a series of setbacks. Soon after Flight Unlimiteds completion, Blackley was fired from Looking Glass. He went on to design Jurassic Park: Trespasser at DreamWorks Interactive and later spearhead the Xbox project at Microsoft.
Gameplay
Flight Unlimited is a three-dimensional (3D) flight simulator video game: its gameplay is a simulation of piloting real-world airplanes. Players may control the Bellanca Decathlon, Extra 300S, Pitts Special S-2B, Sukhoi Su-31 and Grob G103a Twin II sailplane. The game begins at the fixed-base operator (FBO) interface—a traversable 3D room whose contents represent menu options. For example, the player interacts with a row of scale airplane models to select an aircraft, and with a world globe to change airfield locations. Six settings are available, including Sedona, Arizona and Springfield, Vermont.
The player may choose to begin flight on a runway or taxiway, or in the air. Aircraft are controlled via keyboard, joystick, head-mounted display or specialized input devices such as pedals. During flight, several third- and first-person camera angles may be selected. For example, the third-person Flyby View places the camera in front of the plane as it flies past, while the first-person Three-Way View displays more information about the plane's position and speed than other angles. Certain camera angles, including the Three-Way View and 3-D Cockpit view, provide the player with simulated flight instruments such as an altimeter, airspeed indicator, accelerometer, variometer and tachometer. The game is designed to allow players to perform aerobatic maneuvers such as the Immelmann turn, tailslide, Lomcevak and Cuban Eight. Performances may be recorded and played back, with controls that allow the player to pause, rewind and fast forward. At any time, the player may stop a recording and resume flight from that point.
The game contains lessons that cover basic and advanced flight techniques, ranging from rudder turns to challenging aerobatic maneuvers. A simulated flight instructor offers real-time advice based on the player's performance. Certificates are earned by performing well during lessons. In Hoops courses, the player undertakes a time trial through rings that float in the sky, with the option to enable a "ghost plane" of the highest score. Four types of Hoops courses are available: Basic, Challenge, Distance and Trick. The last is intended as a highly demanding test of the player's aerobatic ability. The game's sole non-powered aircraft, the Grob G103a Twin II sailplane, features its own game mode focused on energy management. The player attempts to use the direction of the wind, thermals—which realistically occur above areas that absorb more heat, such as plains and parking lots—and the orographic lift caused by slopes to stay airborne for as long as possible.
Development
Origin
The concept of Flight Unlimited originated from Looking Glass Technologies' discontent with contemporary flight simulators. Company co-founders Paul Neurath and Ned Lerner wanted to develop an exceptional game in the genre, and Neurath considered the idea during the production of Ultima Underworld: The Stygian Abyss and Ultima Underworld II: Labyrinth of Worlds. In 1992, Seamus Blackley, who had been undertaking graduate studies in particle physics at the Fermilab research facility, was hired through a want advertisement that Lerner had placed on a bulletin board. At the company, Blackley programmed the physics modeling system for a racing game and designed a large number of standalone physics demonstrations. He became fascinated by physics programming. An amateur pilot and flight devotee, Blackley asked Lerner extensive questions about his earlier game Chuck Yeager's Advanced Flight Trainer, which Blackley held in high regard. In reaction to Blackley's enthusiasm, Neurath suggested that the company develop a "traditional Cessna sim".
However, Blackley instead proposed an aerobatics training simulation, which he had conceived while reading an aerobatics magazine on a Lexington, Massachusetts bus. Collaborating with Ultima Underworld II programmer Greg Travis, he created a thirty page concept document that outlined the game. His core idea was to recreate the "yummy, visceral, fluid feeling that you get when flying a real airplane". He wanted the project to bear more resemblance to a playground than to a video game, and he sought to give it simple controls and realistic terrain to decrease the learning curve for beginners. Blackley assumed the role of project leader and then engaged the team in "flaming sessions" to generate ideas. According to programmer Doug Church, Blackley's concept of the game was not fully developed, but he clearly expressed his thoughts and motivated the team. The first months of the project produced disparate prototypes that demonstrated prospective features. The company committed to full development of the game in early 1993, and production commenced in March.
Production Blackley's first objective was to code the game's simulated physics. He began by deciding on a programming method—in particular, he sought one that would allow aircraft to perform the "knife-edge spin" maneuver that he had witnessed at air shows. In 1995, he said that he had never played a flight simulator with an accurate sense of flight. He later described his belief that the genre had stagnated, and that flight games were evaluated "by [their] implementation of the standard feature set", rather than by their enjoyability. Blackley researched physics programming in contemporary flight simulators, and he discovered that many used large databases of wind tunnel and plane sensory equipment information to dictate how aircraft would operate in prerecorded scenarios. Higher-end simulators used a "Newtonian" system, in which algebra-based measurements of force vectors determine a plane's position in real-time. However, Blackley believed that neither system correctly simulated the experience of flight.
In reaction, he used his knowledge of particle physics to create a real-time computational fluid dynamics (CFDs) model for Flight Unlimited. The result is a simulated atmosphere: air acts as a fluid that automatically reacts to the shape of any object placed within it. Blackley gave the example that a lawn chair, if placed within the game's real-time CFDs model, would fall merely because of its shape. The game's planes fly because the interaction of their architecture with the atmosphere creates lift, as with real-world aircraft. Changes in the plane's direction are caused by the interaction of their flight control surfaces (ailerons, elevators and rudders) with the simulated atmosphere. Because it simulates the dynamics of flight in real-time, the system allows for aerobatic maneuvers that were impossible in previous flight simulators. In 1994, Blackley said that it was possibly the first flight code designed for aerobatics. In constructing the CFDs model, Blackley and the team built from the Navier–Stokes equations of fluid motion, which Blackley described as "horrible, complicated partial differential equations". According to Computer Gaming World, Blackley did not seek to represent the equations with perfect accuracy, and he was satisfied when the results were consistent and the sensation that they generated was correct.
After programming a basic version of the CFDs model, Blackley used several programs to examine the simulated currents of air that flowed across a model of a flat plate. He adjusted the code until the plate fell realistically, and then constructed test models for a plane wing and fuselage. He eventually built a complete but dysfunctional plane by using data from "pinhead books". By reading aircraft design manuals, he discovered that the problems were caused by his plane's incorrect tail and center of gravity. Following this, he created an exact three-dimensional model of the Extra 300S over roughly three days. As he had not yet simulated the physical attributes of its propeller, Blackley programmed the plane to be propelled from the rear. However, the accurate model performed properly in the simulated atmosphere.
Artists Mike Marsicano and Kurt Bickenbach played critical roles in the creation of the game's aircraft models, which were built in 3D Studio. As reference material, the team photographed real planes at several airfields, and they received blueprints and datasheets from aircraft manufacturers. The game's Grob G103a Twin II sailplane was based directly on the one that Blackley owned at the time. The sophistication of the real-time CFDs complicated the 3D modeling process, as the planes required accurate geometry to fly properly. While attempting to meet this goal, however, Bickenbach said that the models he created were overly detailed, which caused the team to struggle with performance issues related to the high number of polygons. Reducing the number altered the plane's shape, which in turn reduced its flight realism; this necessitated a balance between performance and accuracy. To obtain audio for the planes, Greg LoPiccolo and Tom Streit—former bassist and road manager, respectively, of the band Tribe—visited a Florida importer of Russian aerobatic aircraft. The two placed microphones inside the cockpits and next to the engines, and they flew each plane at multiple speeds while recording with a digital audio tape machine. Combining this material with digital recordings of wind sounds, the team fashioned a physics-based sound system: sounds of the wind and engine are altered in real-time based on wind speed in the game.