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How 3DO creates video games

How 3DO Creates Video Games
by Jeff Tyson

Video games are enormously popular all over the world. In fact, the video game industry is a
multibillion dollar a year machine -- A successful video game, just like a popular music CD, can
sell hundreds of thousands or even millions of copies!
You have probably wondered what goes into making a good video game. You may even want to
get into the business yourself. Here are some of the questions that you may be wondering about:

Where do game ideas come from?
How many people are involved in making a game and what do they do?
How is a game developed?
How does a game get to my local store?

Photo courtesy 3DO

3DO's newest game is called Portal Runner.

To understand the entire process of video game development,
we went to the folks at 3DO. 3DO is a major publisher of video
games, with several popular titles for the Nintendo 64 and other
game consoles, as well as PC and Mac computer systems. In
this edition of How Stuff Works, we will follow the development of Portal Runner TM, a new
game from 3DO. You will learn about the game's technology, how the idea was developed and
how the game will be distributed.

Where the Game Comes From
All games start with an idea. But where that idea originates can be traced to one of several

An original concept presented by an employee
An original concept pitched to the company by an outsider
A sequel to an existing game
A spinoff based on a character from an existing game
A game based on an existing character or story (such as movie, TV or comic characters)
A simulation of another game medium (such as board games and card games)
A game targeted to a specific demographic
A simulation of a real world event
A game designed to take advantage of a specific game platform (such as the Internet or
an advanced interactive game system).

Once the idea is accepted by the company as a viable game, then a preproduction team is
assembled to begin developing the idea into a fully realized game. How the game develops
depends greatly on what type of game it is. The story line and design of a game based on an
existing movie or comic character are going to be much more restricted than those for a
completely original game concept. Likewise, a simulation based on a real world event, such as a
baseball game, has definite boundaries in what can be done.

Video games can be extremely different from one another. And while there is a huge variety of
games available, most fall into certain broad categories:

3D Action/Adventure (Portal Runner, Army Men, Tomb Raider)
Simulation (Army Men: Air Combat, Aero Fighters' Assault, Maestro Music)
Sports (Sammy Sosa High Heat Baseball, Tony Hawk Pro Skater)
Strategy/Role-playing/Adventure (Heroes of Might and Magic, Zelda, Final Fantasy)
Fighting (Mortal Kombat, SoulFighter)
Puzzle (Tetris, Pokemon Puzzle League)
Shooter (Defender, Silpheed)
Platform (Sonic, Super Mario Brothers)
Racing (Mario Kart, Tokyo Xtreme Racer)
Conversion (American Arcade Pinball, Who Wants to Be a Millionaire?)

Of course, a lot of games include aspects from more than one of these categories, and a few
games are in a category all their own.

Vikki Grimm

Sarge's Heroes, one of the
games in the Army Men series

In the case of Portal Runner, 3DO took a character from one of its most popular franchises and
gave her a spinoff title of her own that falls into the 3D Action/Adventure category. The
character, Vikki Grimm, has figured prominently in the Army Men TM universe. Portal Runner is
not considered a sequel because 3DO is taking one character and building an entirely new game
universe around her. As you learn about the development of Portal Runner, remember that many
of the steps in the process could change significantly for a different title based on the nature of
the game being developed.

Planning the Game
The preproduction team normally includes one each of the following people:

Software Engineer/Programmer

Sometimes a team will not have every one of these people and other times it will have more than
one person in a particular category. Another person assigned to the game from the outset is the
producer. While the director provides the overall vision and direction for the game and is in
charge of managing all the team members, the producer is in charge of the business side. For
example, the producer maintains the production and advertising budgets and makes sure that the
game stays within budget.
The first thing that the preproduction team does is develop the story line for the game. Think of
this like writing the outline for a novel. The story line identifies the theme of the game, the main
characters and the overall plot. Also, areas in the game where a full motion video (FMV)
sequence would help the story along are established. An important part of developing the story
line is knowing the nature of the game. This means that the game designer is typically involved
from the very beginning; he/she is responsible for things like:

identifying traits and features of the game
the type of gameplay and user interaction that is developed
how the game will use the technology available on a particular platform (video game
system or computer).

Brigitte Blue, Vikki's nemesis

Vikki in a spacesuit

Portal Runner is a linear game. This means that you follow a predetermined path and accomplish
specific goals to complete the game. The pattern of the game is: FMV1, Play1, FMV2, Play2,
FMV3, Play3 and so on until the end. Each play portion has a different look, theme and goal, all
of which combine to form the game world. Linear play makes the story line much easier to create
than it would be for a game that branches or has multiple endings. Branching games can
contain a series of paths that all lead to the same ending. Even more difficult are branching
games that can result in one of several different endings, depending on the path taken. Of
course, the type of game largely determines what the story line and style can be. A puzzle or
sports game would not require as detailed a story line as a 3D action or role-playing game.
Once the story line is developed, the team creates a set of storyboards. A storyboard is a
collection of still drawings, words and technical instructions that describe each scene of the
game. These include storyboards for the FMV sequences that introduce the story and continue it
between the periods of actual gameplay. Here are several examples:

A storyboard for the opening FMV in Portal Runner

Close-up view of the storyboard images

In addition to storyboarding the game, the designers will map out the different worlds, or levels of
play, within the game during the preproduction phase. The attributes of each world and the
elements contained within it are pulled directly from the story line.

Developing the Game
Once the storyboards and overall game level designs are complete, the game enters the
production phase. The preproduction team expands as needed to include additional artists,
programmers and designers.
3DO's artists begin developing the 3D models that will make up the worlds of Portal Runner using
a software application called 3D Studio Max. Richly detailed texture maps are created for each
object. While the game developers at 3DO create the actual game environment using these
models and textures, another division of the company, PlayWorks, will use the same models to
develop the animated FMV sequences for the game.

A good example of the models and textures in Portal Runner

Meanwhile, the programmers are writing custom code in C programming language that will
provide the framework for the game objects. A lot of code is pulled from the company's library,
which is a bank of already-developed code that can be repurposed for different games. Some of
the code is the 3D engine, an application that generates all the polygons, shadows and textures
that you see. Another piece of code is the artificial intelligence component. This is the logic of the
game. It establishes the physics of the game, detects interaction and collisions of objects and
controls movement of the characters. Development of the game code is done using a special
development version of the particular game system that has increased memory, a SVGA monitor
connection, a network connection and a hard drive.
All the bits and pieces -- objects, textures and code -- are fed into a special utility called a tool
chain that combines the pieces into one big piece of code. The tool chain makes code that is
executable on a specific platform, which basically means that the game code will actually run on
the game system that it was designed for. To test the game, Portal Runner director John Salera
uses another specialized game console built for debugging games.

The Game World
Portal Runner uses an over-the-shoulder perspective. You, as the game player, seem to be
hovering in the air slightly behind the character you are controlling. As your character moves
around, you see the world of the game stretch out into the distance. But what you are really
seeing is a very clever illusion reminiscent of the backlots of Hollywood!
The world that Vikki can actually interact with in Portal Runner is a very defined area. If you could
pull the camera view up in the air, you would see that the play area is completely self-contained.
Other parts of the world that you can see in the distance are actually two-dimensional images
mapped onto a flat surface that surrounds the play area like a barrel. The sky is created in the
same way, by mapping the sky image onto a large dome or cylinder that fits over everything else.
Look at the example below to get a better idea of how this works.

Click on the magnifying glass to move your viewpoint away
from the game character. As you move farther away, you will
see the edges of the game world and the dome that surrounds
it with the city skyline and sky mapped onto it.

The production team constantly looks for ways to add cool effects without degrading the
performance of the game. A good example of this is the reflections of objects on shiny surfaces,
like the chess board in the medieval world of Portal Runner. The chess pieces and characters
moving around on the chess board appear to have detailed reflections on the polished surface of
the chess board. What is actually happening is that a second version of each object is positioned
upside-down just below the semi-transparent surface of the chess board! The upside-down
version moves in concert with the "real" version of the object, providing an illusion of reflection.

Polygons, Shading and Skeletons
The vast majority of 3-D objects created for computer games are made up of polygons. A
polygon is an area defined by lines. To have a polygon, you must have at least three lines.

A simple triangular polygon. Each point of the triangle is a vertex.

The lines connect a series of coordinates in the three-dimensional "space" the computer creates.
The point where the lines connect is known as a vertex. Each vertex has X, Y and Z coordinates.

X determines the position relative to right or left in the virtual space
Y determines the position relative to top or bottom in the virtual space
Z determines the position relative to front or back in the virtual space

Once each polygon has a set of vertices to define its shape, it needs information that tells it what
to look like. There are four common ways to do this:

Flat shading

Gouraud shading
Phong shading
Texture mapping

Flat shading simply assigns a single color to a polygon. It is very simple and fast, but makes the
object look artificial. Gouraud shading is more involved. Colors are assigned to each vertex and
then are blended across the face of the polygon. Since each vertex is typically associated with at
least three distinct polygons, this makes the object look natural instead of faceted. Look at this

The same object with flat and Gouraud shading applied.

You will notice that the ball with Gouraud shading appears much smoother than the flat shaded
one. But look closely at the outlines of the two balls. That is where you can tell that both balls
have the exact same number of polygons!
A more complex version of shading, Phong, is rarely used in games. Whereas Gouraud shading
interpolates colors by averaging between the vertices, Phong shading averages each pixel based
on the colors of the pixels adjacent to it.
Another common technique for determining the appearance of a polygon is to use texture
mapping. Think of texture mapping as wrapping a present. Each side of the box you are
wrapping is a blank polygon. You could paint the box, but it would be very difficult to make it
match all the designs on the wrapping paper. However, if you take the wrapping paper and tightly
cover the box with it, you have completely transformed the box with just a little effort.
Texture mapping works the same way. Mapping requires the use of another image. Essentially,
this other image is stretched over the object like a skin. Most video game consoles and computer
graphics adapters contain a special chip and dedicated memory that store the special images
used for texture mapping and apply them to each polygon on the fly. This allows games such as
Portal Runner to have incredibly detailed 3-D environments that you can interact with in real time.
The characters in a game have skeletons. Similar to our own skeleton, this is a hidden series of
objects that connect with and move in relation to each other. Using a technique called parenting,
a target object (the child) is assigned to another object (the parent). Every time the parent object
moves, the child object will follow according to the attributes assigned to it. A complete hierarchy
can be created with objects that have children and parents. Here's an example for a human

The closeup shows the skeleton's arm. You see that the finger
objects are children to the hand object, which in turn is a child
to the forearm object.

Once the skeleton is created and all of the parenting controls put in place, the character is
animated. Probably the most popular method of character animation relies on inverse
kinematics. This technique moves the child object to where the animator wants it, causing the
parent object and all other attached objects to follow. Another method that is popular for games is
motion capture, which uses a suit of sensors on a real person to transmit a series of coordinates
to a computer system. The coordinates are mapped to the skeleton of a game character and
translated into fluid, realistic motion.
Each character's range of motion is programmed into the game. Here's a typical sequence of

You press a button on the controller to make the character move forward.
The button completes a circuit, and the controller sends the resulting data to the console.
The controller chip in the console processes the data and forwards it to the game
application logic.
The game logic determines what the appropriate action at that point in the game is (move
the character forward).
The game logic analyzes all factors involved in making the movement (shadows, collision
models, change of viewing angle).
The game logic sends the new coordinates for the character's skeleton, and all other
changes, to the rendering engine.
The rendering engine renders the scene with new polygons for each affected object,
redrawing the scene about sixty times each second.
You see the character move forward.

Finishing Touches
After the basics are in place, the production team begins to refine the game. Part of this
refinement involves optimizing the game code, polygon count and logic, including adjusting the
clipping planes and culling. The polygon count (number of polygons on screen at the same
time) is a major factor in the smooth rendering and quick response of a game. Portal Runner
often has more than 50,000 polygons on screen!

Clipping planes determine whether or not polygons in the field of view will be rendered. This
depends on how close to the camera the polygons are. Typically, the near clipping plane will not
render polygons that are close enough to intersect the plane of the camera. This keeps your
viewpoint in the game from intersecting another object and thus blanking out. And the far
clipping plane is normally set at the point where the screen resolution causes the details to
become impossible to see. There is no need to render objects that you cannot see.

Only the portions of the objects in view are rendered.

This leads to another area of optimization. While the far clipping plane does not render entire
objects that are too far away, culling means that the video game system does not render the parts
of objects that are outside your viewing area. For example, when you look at a building, you
normally only see one or two sides of the building. In a game, you can increase performance by
not rendering the other sides of the building until you move around to the point that you can see
them. And as you move, the game can stop rendering the things you can no longer see.
One of the refinements that John Salera said 3DO wanted to make to Portal Runner was to
determine where they could eliminate polygons through culling in order to increase the polygon
count for Vikki, from 1,500 polygons to 3,000. They want to do this without increasing the overall
number of polygons onscreen. By increasing the polygon count of a specific object (like Vikki), the
object can be made to look smoother and more realistic.
Periodically during the development of the game, 3DO sends builds (partially complete versions)
of the game to the game console maker. This is done to keep the console maker informed about
how the game is developing and to ensure that there are no surprises that the manufacturer
might take issue with.
As the game nears completion, it enters the post-production phase. This phase has several

Game versions
Product testing
ESRB review
Marketing and advertising

Once the game is done, an alpha version is sent to designated game testers. This preliminary

version is a first pass meant to find any major flaws in the game. The problems are identified and
the game is released again in beta form. The beta version is tested exhaustively to find any bugs
and discover ways to further optimize the game. After the items found in the beta version are
fixed, the final candidate is released.
Sometime during this period, the game is sent to the Entertainment Software Rating Board
(ESRB) to be given a rating. If the game is released before a final rating is set, it will have an RP
(Rating Pending) in the rating box.
During post-production, the marketing engine begins to ramp up. The game is advertised in print,
on the Web and oftentimes on TV. Quite often, a game that is a hit or has a very memorable
character provides the company with opportunities for merchandising and licensing. Comic
books, cartoons, movies and amusement park rides have all spun out of the popularity of certain
video game characters. Products such as clothing, toys and board games often display
characters from the game. A popular video game character can be a real marketing gold mine for
the parent company.

Distributing the Game
A major difference in creating a video game for a console versus a normal PC is the approval and
distribution process. Console manufacturers normally require strict licensing agreements between
themselves and companies that wish to develop games for their system. We will outline the
process that 3DO goes through with the game console makers they work with.
Every company that develops games for a video game system manufacturer is considered a
third party licensee. Here's how it breaks down:

ƒ Develops the game idea
ƒ Creates the game
ƒ Tests the game
ƒ Markets the game
ƒ Distributes the game
Console maker
ƒ Approves the game idea
ƒ Tests the game
ƒ Reviews and approves the game
ƒ Manufactures the game

When 3DO submits the game to the console maker, the testing and review process can be very
rigorous. The game may be sent back to 3DO with requests to change certain parts before
resubmitting it.
Once the game is approved, 3DO places an initial order with the console maker that must be paid
up front. The console maker sends a master copy of the game to one of its manufacturing plants.
The first run of a typical 3DO game is between 150,000 and 300,000 units. It normally takes a few
weeks from the time an order is placed until the games are delivered to 3DO's warehouse
distribution center in Atlanta, Ga.
The games come packed at between 500 and 2,000 games per pallet. A tractor-trailer can carry
about 40 pallets of 2,000 games each (about 80,000 games). That means it could take four trucks
to deliver 320,000 copies of a single title!
During this process, 3DO has been taking orders for the game from resellers. The resellers send
their own trucks to the 3DO warehouse in Atlanta to pick up their copies of the game. Quite often,
the games are pulled directly off the trucks bringing them in from the manufacturer, split up and

reboxed, then put right back on the trucks for the resellers!
Specialty retailers like Babbages and Electronics Boutique try to get the games from the
distribution center to their store shelves as quickly as possible. Big box retailers like Wal-Mart,
Kmart and Target are not as rushed, and typically ship the games to their stores along with other
Many people mistakenly assume that the cost per game to the parent company is minimal and
the profit huge. This is seldom the case. While the actual material costs for the CD duplication,
box and manuals may only be a few dollars per unit, there are a lot of other costs incurred:

Console licensing royalties (about $3 to $10 per unit for the console maker)
Game development costs (typically several millions of dollars)
Advertising (anywhere from $1 million to $4 million for most games)
Salaries for the production team (a typical game might employ 40 people for a year or
Other licensing fees (particularly in sports titles, where the professional sports
organization and any featured athletes tend to receive royalties for each unit sold)
Operational costs (the costs of running the company must be split between the various
games sold)

Game companies also have to take into account the short lifespan that most games enjoy. Since
the technology that video games thrive on is continually improving, the games that are cutting
edge today will seem slow and clunky in just a year or two. It's amazing that companies like 3DO
continue to provide us with such incredible entertainment year after year!

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