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26.4. Game Types 663
new games in that genre; see Figure 26.2. On the other hand, puzzle games have
typically had relatively simplistic graphics, so most game developers will not in-
vest large amounts of programming or art resources into developing photorealistic
graphics for such games.
Although most games aim for a photorealistic look, a few do attempt more
stylized rendering. One interesting example of this is Okami, which can be seen
in Figure 26.3.
The management of development resources also differs by game type. Most
games have a closed development cycle of one to two years, which ends after
the game ships. Recently it has become common to have downloadable content
(DLC), which can be purchased after the game ships, so some development re-
sources need to be reserved for that. Persistent-world online games have a never-
ending development process where new content is continually being generated,
at least as long as the game is economically viable (which may be a period of
decades).
The creative exploitation of the specific requirements and restrictions of a
particular game is the hallmark of a skilled game graphics programmer. A good
example is the game LittleBigPlanet, which has a “two-and-a-half-dimensional”
game world comprising a small number of two-dimensional layers, as well as a
Figure 26.4. The
LittleBigPlanet
developers took care to choose techniques that fit the
game’s constraints, combining them in unusual ways to achieve stunning results.
LittleBig-
Planet
c
2007 Sony Computer Entertainment Europe. Developed by Media Molecule.
LittleBigPlanet is a trademark of Sony Computer Entertainment Europe.
(See also Plate
XXXV.)
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664 26. Computer Graphics in Games
non-interactive background. The graphics quality of this game is excellent, driven
by the use of unusual rendering techniques specialized to this type of environ-
ment; see Figure 26.4.
26.5 The Game Production Process
The game production process starts with the basic game design or concept. In
some cases (such as sequels), the basic gameplay and visual design is clear, and
only incremental changes are made. In the case of a new game type, extensive
prototyping is needed to determine gameplay and design. Most cases sit some-
where in the middle, where there are some new gameplay elements and the visual
design is somewhat open. After this step there may be a greenlight stage where
some early demo or concept is shown to the game publisher to get approval (and
funding!) for the game.
The next step is typically pre-production. While other teams are working
on finishing up the last game, a small core team works on making any needed
changes to the game engine and production tool chain, as well as working out the
rough details of any new gameplay elements. This core team is working under a
strict deadline. After the existing game ships and the rest of the team comes back
from a well-deserved vacation, the entire tool chain and engine must be ready for
them. If the core team misses this deadline, several dozen developers may be left
idle—an extremely expensive proposition!
Full production is the next step, with the entire team creating art assets, de-
signing levels, tweaking gameplay, and implementing further changes to the game
engine. In a perfect world, everything done during this process would be used in
the final game, but in reality there is an iterative nature to game development
which will result in some work being thrown out and redone. The goal is to min-
imize this with careful planning and prototyping.
When the game is functionally complete, the final stage begins. The term
alpha release usually refers to the version which marks the start of extensive
internal testing, beta release to the one which marks the start of extensive external
testing, and gold release to the final release submitted to the console manufacturer,
but different companies have slightly varying definitions of these terms. In any
case, testing, or quality assurance (QA) is an important part of this phase, and it
involves testers at the game development studio, at the publisher, at the console
manufacturer,and possibly external QA contractors as well. These various rounds
of testing result in bug reports which are submitted back to the game developers
and worked on until the next release.
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26.5. The Game Production Process 665
After the game ships, most of the developers go on vacation for a while, but
asmallteammayhavetostaytoworkonpatches or downloadable content. In
the meantime, a small core team has been working on pre-production for the next
game...
Art asset creation is an aspect of game production that is particularly relevant
to graphics development, so I will go into it in some detail.
26.5.1 Asset Creation
While the exact process of art asset creation varies from game to game, the outline
I give here is fairly representative. In the past, a single artist would create an
entire asset from start to finish, but this process is now much more specialized,
involving people with different skill sets working on each asset at various times.
Some of these stages have clear dependencies (for example, a character cannot be
animated until it is rigged and cannot be rigged before it is modeled). Most game
developers have well-defined approval processes, where the art director or a lead
artist signs off on each stage before the asset is sent on to the next. Ideally an
asset proceeds through each stage exactly once, but in practice changes may be
made that require resubmission.
Figure 26.5. A mesh being modeled in Maya, with associated texture parameterization.
Image courtesy Keith Bruns.
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666 26. Computer Graphics in Games
Initial Modeling
Typically the art asset creation process starts by modeling the object geometry.
This step is performed in a general-purpose modeling package such as Maya,
MAX or Softimage. The modeled geometry will be passed directly to the game
engine, so it is important to minimize vertex count while preserving good sil-
houettes. Character meshes must also be constructed so as to be amenable to
animation.
In this stage, a two-dimensional surface parameterization for textures is usu-
ally created. It is important that this parameterization be highly continuous, since
discontinuities require vertex duplication and may cause filtering artifacts. An
example of a mesh with its associated texture parameterization is shown in Fig-
ure 26.5.
Texturing
In the past texturing was a straightforward process of painting a color texture, typ-
ically in Photoshop. Now specialized detail modeling packages such as ZBrush
or Mudbox are commonly used to sculpt fine surface detail. Figures 26.6 and 26.7
show an example of this process.
Figure 26.6. The mesh from Figure 26.5 has been brought into ZBrush for detail modeling.
Image courtesy Keith Bruns.
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26.5. The Game Production Process 667
Figure 26.7. The mesh from Figure 26.6, with fine detail added to it in ZBrush.
Image
courtesy Keith Bruns.
Figure 26.8. A visualization (in ZBrush) of the mesh from Figure 26.6, rendered with a
normal map derived from the detailed mesh in Figure 26.7. The bottom of the figure shows
the interface for ZBrush’s “Zmapper” tool, which was used to derive the normal map.
Image
courtesy Keith Bruns.
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