Bill Gates' favorite game opened an era in 40 years

By Matthew S. Smith

Source|https://spectrum.ieee.org/microsoft-flight-simulator#toggle-gdpr

原标题：FLIGHT SIMULATOR GAVE BIRTH TO 3D VIDEO-GAME GRAPHICS

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In 1999, Bill Gates wrote a moving tribute to the Wright brothers, who described their wing invention as "the World Wide Web of that era" that gave people a global perspective. This also paved the way for Microsoft's later acquisition of Flight Simulator.

And, like the Wright brothers' original flying machine, the meaning of the game "Flight Simulator" has long been not only "flying" itself, but also the change of perspective brought about by "flying". Flight Simulator promises to put the whole world into your computer, and it delivers on that promise. That's why it's the best-selling flight simulation series in the world. Its latest version has sold more than 2 million copies.

Although 2022 marks the 40th anniversary of Microsoft Flight Simulator, it is actually older than its official release in 1982 and is still under active development. It has also become the second oldest video game. (The oldest was The Oregon Trail, which came out in 1971 and is still with us today.) ）

The core of the Flight Simulator series of games is not "gamification", but the "technical magic" it uses to simulate the flight experience and the ground under your feet. Its focus on "truthful descriptions" reflects the background of game developers.

01 Passion for flying

Bruce Artwick studied electrical engineering at the University of Illinois at Urbana-Champaign, but he still found time to pursue a dream that many teenagers had dreamed of but few realized: he learned to fly an airplane. It was also during the university's flight training program that he met Stu Moment, who would become his business partner.

In 1976, Atwick wrote his master's thesis on a flight simulator he designed to run on a PDP-11 microcomputer at Digital Equipment Cooperation. Its three-dimensional presentation can reach 9 frames per second, which is excellent in its time.

Atwick then landed a job at Hughes Aviation in California while continuing to work on 3D graphics in his free time.

Stu Moment and Bruce Artwick | Stu Moment, the two founders of Flight Simulator

In 1977, he wrote an article for Kilobaud describing his creation of the "sunLogic 3D Micrographics Package," which combined 3D technology with a microcomputer equipped with the popular Motorola 6800 microprocessor. Given that so many readers were interested in it, Atwick wanted to ask for help and turn the software into a business. He reconnected with Stuart Morment and founded sunLogic together.

Dave Danhart is the second employee of sunLogic. According to his recollections, the company was driven by Atwick's 3D software, which in turn was updated and iterated with the rise of microcomputers. "What Bruce and Stu are selling is basically a 3D software package for microcomputers," Danhart said. "Tandy's TRS-80 was a microcomputer, and I think the Apple II was there."

Atwick often said in his speeches that sunLogic's software could be used for "flight simulation," a suggestion that surprised the audience. Showing the perspective of soaring above the Earth on a computer? Most people have never seen anything like this. Encouraged by the audience, Artwick decided to bring it to life.

THE EVOLUTION OF FLIGHT SIMULATOR, FROM LEFT TO RIGHT, IS THE EFFECTS ON APPLE II, ATARI AND MICROSOFT DOS | JOSEF HAVLIK AND MICROSOFT

So, at the end of 1979, Flight Simulator was introduced on the Apple II and TRS-80, with wireframe graphics and single-digit frame rates. It does not describe real airspace or modern aircraft. Instead, players fly a World War I-era biplane, based on the famous Sopwith Camel. But at the same time, its first-person 3D visuals represented the advanced state of the day, even before more famous titles like Atari's Battlzone.

Danhart said, "Very early on, Bruce saw a potential market for Flight Simulator. When microprocessors became ubiquitous, Bruce's opportunity came." As Bruce says, "If I put my flight simulation idea on a cheaper computer and let it run, there must be a market."

Bruce is right. In September 1982, Computer Game World magazine ranked Flight Simulator as the fourth best-selling product to date.

IBM had been eager to showcase its PC platform, so it contacted sunLogic to fit Flight Simulator onto its new hardware. At the same time, Microsoft, which is deeply developing IBM PC DOS, quickly called, making similar requests, but with better conditions.

Eventually, Microsoft and sunLogic partnered to license Flight Simulator, although Bruce could continue to own his company for years to come.

At the end of 1982, Microsoft Flight Simulator was officially released, and continued to be refined in the following months, reflecting the progress of microcomputers. Page animations change from monochrome to color (on PCs with the appropriate hardware), and the display refresh rate increases to 15 frames per second. One reviewer called the Microsoft Flight Simulator experience "very smooth."

In the game, players can fly a Cessna 182 aircraft in four real-world areas, including Chicago and Seattle.

For the first time ever, people can realize their dream of being a pilot at home and on a computer – flying a real plane through real terrain and taking off and landing on a model of a real airport.

This realism extends to the Flight Model, which uses an effective technique: lookup tables. This is because early IBM computers could not support real-time calculations of aircraft forces. But fortunately, aircraft manufacturers can help with the answer, which gives sunLogic a scalable foundation.

"Basically, you enter the requirements, and the simulator can simply do a lookup and output the results," Danhart said. "Now, due to resolution and memory limitations, you don't have a very large query table, but you can have a medium, even small, query table, and you can modify between data points."

With the flight model, sunLogic expands the scope of simulation.

Microsoft Flight Simulator 2.0 (1984) simulated the entire United States, Microsoft Flight Simulator 3.0 (1988) joined the Gates Learjet 25 and a large number of airports, and Microsoft Flight Simulator 4.0 (1989) added random events, including weather.

FLIGHT SIMULATOR CONTINUES TO EVOLVE FROM 1995 TO 2022 | JOSEF HAVLIK AND MICROSOFT

In 1993, Microsoft Flight Simulator 5.0 introduced a new killer feature: textures, which visually subverted the look of the game. Previously, the land between airports was represented by patches of color, green for forests, gray for cities, and blue for water.

Today, textures offer new details. Starting with Microsoft Flight Simulator 5.0, these details are based on satellite imagery. Therefore, Flight Simulator will be the first opportunity for many people to see satellite imagery in real-time 3D software.

Flight Simulator's first decade on the market was a period of steady upswing. However, there has been an undercurrent behind this, and Artwick and Mormente often disagree. By around 1980, they worked separately, with Momt during the day and Artwick at night. Eventually, in the late '80s, the split became permanent, and Artwick left sunLogic to form the Bruce Artwick Organization (BAO). 1988's Flight Simulator 3.0 became the last version to belong to sunLogic.

Perhaps, it was because of this split that Atvik decided to sell Flight Simulator to Microsoft in 1995. Although, this could not be confirmed by Atwick, employees familiar with the matter revealed that it was a sudden but not surprising decision, even though Atwick has spent nearly two decades working on the business, although the team also has disagreements with Microsoft.

Paul Donland served as a group manager at BAO the year prior to the Microsoft acquisition. "I think ultimately Microsoft wants absolute control of Flight Simulator, not Artwick holding it," he said. "We're a small company, we play by the rules of a small company, and that sometimes causes problems for people at Microsoft. It's easy for us to say no, and it makes them very frustrated."

02 Microsoft in power

With the advent of the Windows 95 operating system, a new chapter of Microsoft Flight Simulator has begun. At the flashy launch of Windows 95, Jay Renault relied on media attributes to convince consumers that "it's time to retire MS-DOS computers and buy Windows computers." (By the way, it was this push that brought the game into my sight: Microsoft Flight Simulator for Windows 95 was bundled with my first Windows 95 computer.)

Moving Flight Simulator to Windows is no small feat. The game is deeply rooted in MS-DOS and the increasingly mysterious software development practices of the early 80s of the 20th century. Windows 95 could theoretically run MS-DOS applications, but it wasn't a good fit for Flight Simulator.

SunLogic's Danhart explains, "Actually, up to this point, Flight Simulator still doesn't really use Microsoft's operating system: you stuff a floppy disk into a floppy drive and it boots." "I think Flight Simulator was running on Microsoft's smallest MS-DOS, but it just started running and then ignored MS-DOS." The team even boycotted earlier versions of Windows because they feared it would slow down Flight Simulator.

But now that Microsoft is in power, defeat is impossible!

Paul Donland recalls, "When we entered Flight Sim 95, there was a huge port". He credits Mike Schroitt, a software engineer for Lockheed's Prepar3D simulation platform, as a guide. "I can't say how important it is for everything, but a lot of the code has moved from assembly language to C, and it's a huge amount of work."

Moving Flight Simulator to Windows was the first foray into Microsoft's labor culture. It was also only partially successful, as reviewers found that even the fastest home computers had performance issues. As it turns out, the Flight Simulator team's concerns about Windows' ability to handle "simulation" are not unfounded. Nevertheless, "Flight Simulator" is still an indispensable "gimmick" for Microsoft to expand the media influence of Windows 95.

The team went the extra mile on the visuals of Flight Simulator 98, once again pushing the cutting edge with 3D hardware acceleration. Hal Bryan, head of testing, said, "This work takes a long time to test various 3D accelerators that don't yet have a common standard." Fortunately, these tests paid off, and Flight Simulator 98 quelled critics' complaints about fake performance.

In addition, users have benefited from the rise of CD-ROM and DVD-ROM media, which provide room for more detailed textures, more terrain data, and faster data transfer speeds in games.

Gameplay screen for the 40th Anniversary Edition of Flight Simulator | Steam

Jason Dent was initially employed by Microsoft's Encarta World Atlas and soon switched to assisting with Flight Simulator. Satellite imagery improved the simulator's visuals, but its data was still crude, "with sides between 4 and 16 kilometers." In inaccessible areas, entire mountains are missing. To avoid this gap, Dante and his colleagues combined satellite imagery with land-use data while providing scale and precision.

These efforts paid off in Flight Simulator 2000. Flight Simulator 2000 reached a technical milestone: it mapped the entire planet in 1-kilometer increments. Studio manager Scott Belles, who oversaw the team, said, "Early effects demos made Bill. Gates was stunned."

According to Belles' recollection, after showing Bill Gates that the software included every airport on the planet, Gates responded, "You're talking nonsense." It's the dumbest thing I've ever heard." Belles emphasized, "This is Bill Gates' highest form of praise. According to Microsoft gossip, if Bill Gates says this to you, you've succeeded."

And, for a while, Flight Simulator was a real success. The new version hit the bestseller list. The Flight Simulator team also changed its name to Aces Game Studio and created or contracted derivative products such as Microsoft Combat Flight Simulator and Microsoft Space Flight Simulator.

There were even rumors that Microsoft was going to build a general-purpose, world-scale simulation platform, which eventually became Microsoft's Enterprise Simulation Platform (ESP). Although ESP only lasted a few years, it was licensed by Lockheed Martin for its Prepar3D simulation platform. In retrospect, ESP is like a pioneer in the effort to build "digital twins" to simulate and replicate the real world.

However, there is one problem with Microsoft Flight Simulator, and it comes from within Microsoft, and that is the Xbox console. Microsoft introduced the Xbox in 2001 to counter Sony's PlayStation 2, released in 2000. It has a DVD drive and can be connected to the internet through an accessory. Microsoft is concerned that some consumers will see it as a low-cost PC alternative.

Brian said Aces Game Studio has discussed bringing Flight Simulator to Xbox. But the plan was hampered by the need to adjust keyboard and mouse controls to fit the gamepad. Belles believes this has created a rift between Aces Game Studio and Microsoft, and he laments not pushing harder for the Xbox version of Flight Simulator. "I think we will end up with an engine that is stronger, more flexible, more robust, and fit for the future."

Aces Game Studio is independent within Microsoft's Xbox-centric gaming division. It's not hard to understand, when the 2008 financial crisis forced company-wide layoffs, it bore the brunt. It's a nasty surprise for those affected, but over the years some of them have accepted Microsoft's decision to make sense, since the last iteration of the emulator was arguably stagnant, focusing on the strengths of the past and neglecting the new platform.

At the beginning of the layoffs, SunLogic employee Dent was there, and he ended the project. He stayed behind to archive the studio's work, bringing to an end to this era of Flight Simulator.

03 Nirvana rebirth

Jörg Neumann is a Microsoft veteran working on a HoloLens project called HoloTour. This is an immersive virtual reality travel guide that includes a bird's-eye view of places like Machu Picchu, Peru. However, the project also faced challenges, especially in Machu Picchu, where the team actually obtained much lower than expected.

Neumann said: "It was clear that even with photos of the scene, it was very difficult to make a complete, beautiful three-dimensional model." "In response to this, we just said, why don't we just fly the plane overhead and give us lidar data and proper photogrammetry"? (Lidar is a laser-based technique used to estimate the extent of an object, while photogrammetry is three-dimensional information extracted from photographs.)

Cessna C172 aircraft in Flight Simulator |

Although, the plane did not fly overhead, Neumann's point of view changed. He realized that Microsoft already had the perfect solution, and that was Flight Simulator. "Actually, this idea has always been in my head. We should try to enhance our game world with aerial data."

Neumann used data from Bing to create a demonstration of a Cessna flying over Seattle, the same plane and city as in the original Microsoft Flight Simulator. Even at that early stage, it looked spectacular. Progress has been made on the project, and Danhart's record has proven invaluable.

Neumann said, "The codebase and project archiving is very good." The code was sent to Asobo Studios, the main developer of the HoloTour project, and used to preserve compatibility with Flight Simulator X's third-party aircraft, the last iteration of Aces Game Studio release.

Flight Simulator X also retains a "legacy" mode that activates old flight models, preserving the lineage that dates back to 1982.

Today, most Flight Simulator players will love the default "modern" simulation, with models of up to 1500 flight surfaces. The airflow at each point in the simulation is determined not only by the speed and design of the aircraft, but also by the conditions of the surrounding environment, such as weather and nearby terrain.

This level of simulation was unimaginable in 1982, but today it can run on any recent mid-range AMD or Intel processor.

Hal Brian points out that previous simulations would collapse in extreme situations, such as stalling and spinning, so that the plane would behave too wooden and too predictable. He knew because that's how he had tested this thing before. The new simulation accurately simulates airflow on many surfaces, so it is possible to determine when the stall will begin and whether it will turn into rotation.

While Bing's data was helpful in creating Flight Simulator's game world, the team faced obstacles as not every inch of ground had high-quality photogrammetry data.

To fill these gaps, Asobo uses Blackshark.ai's machine learning technology to convert photogrammetric data and satellite photos into "replicas of the Earth's surface."

Blackshark.ai technology automatically creates buildings based on satellite photos and adds buildings where appropriate. Machine learning also corrected for color changes between photos while eliminating clouds and shadows.

The picture of the city below in the 2020 version of Flight Simulator is clearly visible |

Arno Holosi, CTO of Blackshark.ai, said, "We want to have unique buildings, basically you do it through procedural generation, which collects building footprints, roof types, roof colors, zoning, building density and other information." This data is then modified with "archetypes" that fit the style of the geographic region. As a result, all kinds of 3D buildings look real from at least a thousand meters above the ground. This technique can also depict small neighborhoods or even unattended rural houses and buildings, something artists can never accomplish when adding buildings one by one.

Even so, Microsoft's simulations today aren't perfect. A city street may look right, but your house may not. Simulated air traffic is not as busy as it is in reality. Simulated air traffic control information is also often inaccurate or non-existent, especially at medium-sized airports. The simulated weather is often stunningly beautiful, but it only vaguely mimics the real world. Solving these problems, like many of the additional features of Flight Simulator, requires new technology to support it.

However, one of the core achievements of Microsoft Flight Simulator is undeniable: it packs the whole world into your computer. It can even put the whole world in your pocket through Microsoft's xCloud streaming app for smartphones, allowing anyone with a modern smartphone to download Flight Simulator and "soar freely" around the world.

"Our ambition is to replicate the whole world, and we do!"