#7 Controlling AI Health & Hits in Unity3d using RAIN{Indie} Video Lecture | How to make Video Games: Game Editor Tutorial - Game Development

continuing on where we last left off
let's continue on and work on the
artificial intelligence for our is a
zombie shock trooper here so the reason
why we give a shell shock example scene
is so that we can learn a lot from it
and there are two other a eyes inside of
this world one of them is the rat and
the other one is the shock trooper that
is completely you know rigged up with
guns and all that stuff and we can look
at their behavior trees by for example
selecting the rat as you can see it is
it is a pretty good size behavior tree
but not too long and you know it allows
the rat to do all kinds of things now as
you can see at the first root there is a
note that says the red set up and it
calls a class which is called the red
set or set up action now this is simply
a you know a script file that is being
called inside of our project pane and
that script file
you know sets up the rat for you know
all the variables that it needs and all
that sort of stuff and we can take a
look at that so if I take the same name
rat set up action and search for it then
I find a c-sharp script which is inside
of our actions folder for our rainy eye
now if you call a class from you know an
action you want to you know keep it
organized and put it in the actions
folder now if I look at the code of this
script there's nothing really that we
need for this code for our character
because really what it does is it's it
setups you know all kinds of you know
waypoints for the rat and our character
does not have any waypoints so we can
skip cloning this node but if you ever
feel the need in the future this is what
you can do when your character has just
been set up now then there are some
other things here if I go lick on the
rat and I open it up you can see that
there are a couple scripts that the rat
has that we don't have on our character
one of them is a data controller now the
data controller if I click on it you
will see that it selects it inside of
the FPS control library so this script
comes out of the FPS control core
functionality
and the reason why it comes out of the
you know in the core code bases because
it has to do with health and you know
that way you can receive damage from the
player and those kind of things so when
we go back to our shock trooper we want
to create that data controller grab it
and and drop it on side of the character
now it asks us a couple of variables
what is the maximum amount of health
that you want this you know zombie shock
trooper to heaven I'm gonna put 30 and
the current health when he starts up as
thirty as well and the initial health
when he start up as thirty as well so I
can also decide if I want this character
to automatically heal over time I'm just
going to turn it off for now to keep
things easier but you can always turn
that on later let's go back to the red
and just use this as a cheat sheet to
see what's going on now
you can see that in the red AI he is
asking what is the data controller here
and what is the eye eye itself and then
some other extra variables that have
been defined for this rat AI we don't
have this script on our character either
then we have a rain agent and a
character controller let's go back here
we see our character controller here in
a rain agent but we don't have an AI
script there's actually you know
intelligence G changing things for us
that can be read out by the behavior
tree so we'll need one let's go back to
the rat and we're gonna clone it from
him so I'm gonna click on the rat a I
here and that's a JavaScript file which
is inside of our scripts folder and I'm
going to duplicate it edit duplicate and
I'm going to rename it and call it
zombie AI just because you know this is
a cool zombie all right then I'm gonna
double click that one to open it up and
we're going to make some changes to it
because the rat has all kinds of things
going on then we don't need for our
zombie and so we're going to X that out
okay let's take a look here this script
is actually quite easy so don't worry if
this is a bit overwhelming or if you go
oh I use that fist control sorry I don't
have to do all this don't worry it's
very very simple first of all it starts
off is it defines a little bit of a
class it talks to the rain first it
talks to the rain engine
then it defines the AI and the data
controller and then a variable called
hungry because the rat gets hungry and
finds cheese so I'm gonna turn the
hungry variable off by commenting it out
because we don't need that then it goes
into the start function which this
function is called when the game starts
and it defines you know the components
here the AI as well as the data
controller and then it pretty much talks
to our behavior tree and defines these
variables now we have the variable dead
and we have the variable got hit but we
don't need to found food and hungry so
we're gonna take that out as well then
in the update function which runs every
time a frame renders so that's a couple
times a second hopefully more times a
second that means you're a faster
computer and we can see that it updates
these variables inside of the behavior
tree as well so there's health and
there's current time and hungry we only
need the variable health so I'm going to
turn the rest of those off then there's
a custom function apply damage which of
course applies damage to the character
and as you can see there is a use of a
get hit variable and an enemy target so
we're gonna leave those the way they are
for now so if you want to know a little
bit more about what it does you can see
the if statement if the damage source
that comes into this function which
comes out of the FPS control core code
base is equals to gunfire which is our
player and the source object that hurts
us is not an obstacle so it's not an
obstacle in the world then we can apply
you know the god hit set it to true and
define what the enemy target is so where
the actual hit came from so that's what
they script does very very easy so I'm
gonna save that and go back to unity and
I'm going to apply this zombie AI to our
shock trooper here and of course the AI
and the data controller is not defined
but the data controller is right here
and the AI is you know this this
character as well so all we need to do
is drag the shock trooper in both of
these places
now this will not work if you don't have
a data controller apply to the script
you cannot drop it in but you know now
it's all said and done so let's go back
to our shock to Abreu here I'm sorry to
native twins behave let's run the game
and nothing much should have changed but
I'm just checking if we get any funky
errors yes or no no errors we've done
everything perfectly fine and that means
we're ready to set up the rest so let's
go into our got hit mode here and add a
new action and say animate and we need a
new animation here and so we're gonna
animate the hit the fact that the
character got hit let's click on the
shock trooper open up the animations
panel and there are a whole bunch of
animations in you know the 5.1 version
that we already have racked up for you
and one of the animations that are
that's a nice hit animation is called
hit torso front so I'm going to use that
and then it asked us how long is that
animation so how many seconds do we have
to wait until we move on to the next
thing and I think 0.7 is about right
we'll have to take a look in a little
bit and then what's the wrap mode we
only want to play this animation once
because you know it only get hits once
and then what we need to do is add
another note here and call this a where
is it a sign there we go uh-huh
sometimes just search a little bit a
sign and then we're going to set the
Godhead variable back to want to 2 to 0
got hit sorry hold on we need to put
this here got hit equals 0 so why am i
doing this if we come in here we go to
the got hit variable and this node only
gets executed if got hit is equals 1
would we have done in this script then
once it goes in and plays the animation
and wait for 0.7 second
then it goes to the next node which puts
the Godhead back to zero because we're
done getting hit we were very animated
that and it continues and it goes back
now the only problem here is you know
the fine player needs to stop when he is
actually getting hit which you know is
not the case because it executes this
note as soon as health is higher than
zero so what we need to do is we need to
add another precondition that it does
not go in here when you know got hit is
true so it's very easy to do just
right-click the route again create
another sequencer move that one up and
then put the find player inside of this
sequencer and sit and tell this
sequencer that it can only execute when
got hit does not equal one and we have
to give this a name
so I'm just going to call this main
logic so and that will make sure that
the find player will stop so let's test
this and see if I'm you know if I'm
correct so the character does his thing
after a couple seconds now I need to
pick up a gun because otherwise this
layer does not get hurt
we load the gun there we go
fire at him and you saw he got hit for a
second there wonderful and then he gets
stuck because really what happens is he
is dead so health is a lower than zero
so he stops walking towards us but we
never made the logic for him to actually
die but this is excellent progress
already I loved his response so what are
we going to do in the next video is
assigned death animation and it should
be pretty easy from here
alright so follow me on to the next one