316
Game Audio
source of
lighting
to illuminate the objects, cast shadows, and create an illusion
of depth. These components are brought together in a
rendering engine
that
takes the positions of the objects and the camera, their movement, orientation,
lighting, and textures, and creates a 2D moving image that we call a
view
.
Object Behaviours
All the above leads to a wonderful visual experience that characterises the mod-
ern 3D graphical video game. But on its own, a visual experience of a virtual
world does not make a game. Apart from what we see it’s necessary to give
abstract behaviours and properties to objects. These may include health, age,
ownership, cost, etc. The rules of the game stipulate allowable behaviours and
allowable actions by players. For example, a player character may have a given
strength that limits the number of objects he can pick up and carry as personal
inventory.
The Players
Perhaps the most fundamental object is the
player object
, which is an example
of a
character
. It represents both a viewpoint, a state, and an input/output sub-
system. It is the presence, within an artificial world, of the
real
human player
whose actions it represents. Characters are “living,” animated objects that may
be controlled by human players or by AI. A common perspective is
first person
,
where the view is cast through the eyes of the player object. The camera is set
at head height, at the front of the player’s character mesh, and can move from
side to side or up and down as the human player controls the head movement
of his or her player object. This is the most popular configuration and leads
to an
immersive
experience of being within the player character as a “spirit”
or a homunculus that possesses the player object. Another perspective is
third
person
where the human player observes a view outside of the character he or
she controls. This may be fixed above and behind, or may allow free movement
around the world in which the character exists. The somewhat schizophrenic
second-person
perspective puts the player in the body of another character
observing the first (controlled) character object. This is rarely seen except in cut
scenes and asides. For multiplayer games there will be more than one human-
controlled player object within a world, each with its own unique viewpoint.
World Geometry
A special object is the actual
world
itself. The sky, the ground, rivers and pools,
the walls of buildings. Of course this is not a single object, but a collection of
others. Together they define the landscape, what exists, and where. When we
talk about world geometry, for the most part we mean inanimate things. We
mean this within the context of a special and important behaviour called
col-
lision
. In this sense the physical boundaries of object meshes provide a set of
constraints about what may move where; so, for instance, solid things may
not move through one another. Combined with calculations from the
physics
engine
this provides observable behaviours. Soft things may be penetrated by
hard things, elastic things will bounce when they collide, holes may be dug in
Do'stlaringiz bilan baham: |