Game Development Reference
In-Depth Information
Our root node is a parallel type, so the character is always trying to detect gold, but it
still ignores it while traveling. This is because our
move
node will keep running until
it hits its destination, and even if it sees something, it is not interrupted until it gets
there. To fix this, delete the
move
node underneath
ChooseRandomSpot Custom
Action
. Then, change
ChooseRandomAction
to the code shown in the following
screenshot:
This is a big change, so let's discuss what is going on. The
Start
method is the
same as before: store a random position to move to in memory. However, our action
method is different. The first thing it does is it queries the memory for gold. If we have
gold, we don't need to keep moving to our target, so we return failure. Then, we get
our
moveTarget
variable out of memory and check the position of the
Body
vari-
able of our AI. If it is within one unit of the goal, we say that this is close enough and
return success. Finally, if we don't have gold and aren't close to
moveTarget
, we
call on the AI's motor system to move to the target and keep updating it by returning
the running state.
Note
With this update, we could have used a regular class variable to store
moveTar-
get
, but we keep it in memory to keep things consistent.
If you run the demo now, we will see the ships moving around as new gold appears
in more expected ways, as shown in the following screenshot:
