Game Development Reference
In-Depth Information
Additional features
We've just completed creating a driving demo with a car avoiding obstacles, but there
are a few more things you can do with driving AI. We can add brake and drift zones to
help configure the general behavior of the car as it drives around the scene, and we
can integrate Smart Car with other AI systems such as RAIN.
Adding brake zones and drift zones
Another interesting thing you can do with Smart Car is define zones in the level to
either cause the car to brake and slow down or adjust the friction of the car to make it
drift. These are similar to the vector fields we saw in
Chapter 5
,
Crowd Control
, where
we place them in the level to affect the AI, and they aren't visible to the player but
are good to use for scripting level experiences. To create a brake or drift zone in your
game, add a cube to the game (go to
GameObject
|
Create Other
|
Cube
) and scale
and translate the area you want to tag in the level. In the Inspector window for the
cube, set its tag to
BrakeZone
and for a drift zone set the tag to
DriftZone
. Next, in
Box Collider
for the cube, check
Is Trigger
to true, so the car will get a message of
intersecting with a cube but won't stop and collide with it. Lastly, in the
Inspector
win-
dow, uncheck
Mesh Renderer
so that the cube is invisible in the game. Now when
you run the demo, if the car's speed is
25
or over when it enters the brake zone, you
will see it slow down, and if its speed is
15
or over, you will see it drift in the drift zone.
Integrating with other AI systems
In this demo, we've seen that setting up an AI car that drives around is easy to do with
Smart Car. However, what if your game isn't just a driving game but has car driving
as one part of the game? If that's the case, you can mix Smart Car with another AI
system easily. For RAIN integration, import the RAIN package into your scene. Then,
go to
RAIN
|
Create Entity
and then select
Add Aspect: Visual Aspects
. This cre-
ates an entity with an aspect that can be sensed by additional RAIN AI entities you
can create in the scene, making the car just one part of a larger AI system.
