Game Development Reference
In-Depth Information
Programming animation
Besides some artistic advantages, the sprite animation is not ideal: it is hard to re-
adjust or rearrange quickly, it can take some memory resource, and it is not flexible
enough. Therefore, in some situations, it is much more efficient to program some an-
imations by code. The most obvious example is the wheels of a vehicle used in a
game: nobody uses special frame-by-frame animation to rotate them, a simple code
is used instead. Even characters can be animated using such methods; of course it
is pretty hard, but it is possible (recall the description of a Spine animation editor from
Chapter 1
,
Starting the Game
). By using code, you control the general properties of
an image: coordinates, scale, rotation angle, opacity, and even hue. So many things
can be created.
Usually, most of the special effects in games are programmed. The most visual ex-
ample is, of course, the simulation of smoke. To develop good smoke, only one small
sprite is needed, containing an image of one smoke curl. A game should take such a
curl, display it, and begin to move up constantly, rotating and increasing its dimension
while its opacity value is decreasing. The life cycle of the curl looks simple: appear,
fly up, and disappear. There should be dozens of such elements, each of them born
with some random properties as the initial size, the direction of rotation, and opacity.
By tuning the behavior of the curls and playing with their graphic look (a sufficiently
blurred image is considered good), a convincing simulation can be created. You also
need to have passion to make it look good.
Other type of effects based on particles should be programmed as well. Among pop-
ular examples are dynamical clouds, fire, lens flare, sparkles, fireworks, flinders of
objects after a hit, caustics (a pattern made on the surface of water), snow, rain, and
foot prints. There are special particle engines for popular SDKs; nevertheless, in most
cases, they can be developed manually. It looks like an interesting creative challenge.
It is worth mentioning that the effect should not look super realistic. It all depends on
the game's mood and graphic style; in most cases, it only needs to express an essen-
tial idea such as as open fire or falling snow.
In
3robopainter
, there are several programmed animations:
• Dust clouds at the moment of landing on a platform. Some sort of smoke al-
gorithm with a very short life cycle can be used.
• Bubble rotation after the protagonist has made a shot.
