GameMaker Studio - Movement Tutorial Video Lecture - Game Maker Tutorial

alright guys welcome back now that we've
covered the very basic fundamentals of
using game maker what we're going to
look at over this next series of videos
is how to make your first actual kind of
playable game so we're going to be
looking at making a very very simple
top-down scrolling shooting game
the first thing we're going to be
looking at in this video is player
movement so how to move the player
object like left and right the different
ways you can do that through code
through drag-and-drop and all that kind
of stuff so that you can decide what
approach is best for you in your game
and hopefully you'll learn a lot so as
you can see I already have my player
object set up here in the middle of the
screen and if you don't have any idea
what objects are or how I got to the
stage please watch my last video on game
maker basics that'll teach you
everything you need to know just about
this is very basics about how like
sprites backgrounds objects work and so
on so forth so if we go into our player
object over here
the first thing we're going to look at
is how to move left and right through
through the drag-and-drop system and
then I'm going to explain it through
code I did walk through it a little bit
in the last video like the sort of basic
elements of it but we're going to try
and sort of walk through in a bit more
detail and explore what all the kind of
different options you have here what
they all strictly do so that you have a
good idea of all the different sort of
main ways you have to implement movement
in your game and you can decide what's
best for you okay so the first and
easiest method of doing left and right
movement in in the drag-and-drop system
is to go to events add event we're going
to want to make an event for when the
player hits the left key or hits the
right key
or whatever controls you haven't a want
and the basic way we do that is go to
keyboard and I mean we could hit left
here or we could hit right here or we
could go to like others like letters or
whatever or whatever control you want to
set and depending whatever controls your
game is using we're just going to use
left and right for now so if we go to
keyboard left now as I explained before
this event up here called keyboard left
will will trigger whenever the left key
is held so like every single four
rain of the game it'll check to see if
the left arrow key is being pressed and
if it is it'll run these events over
here so the actions we want to take are
obviously now to move our character to
the left so what we want to use here
this very simplest way of doing this is
not actually to use these move fix
things it's to use a jump command this
this arrow arrow pointing to the dot
over here is the jump to position action
so if you drag that into actions you'll
get this little dialogue up here what
this means is we move directly to a
specific position on the screen and if
we take this box called relative at the
bottom here what that means is that
these coordinates are relative to the
object and not to the room because
obviously if we set lay if we turn this
off and we set this to 0 0 0 0 as a
coordinate is like the top left of your
room so that would mean whenever you
have left the character would just walk
to the top left of the room that's not
what we want to happen we want to move
about 3 pixels to the left of where we
were before every frame so we want to
tick relative so our movement is related
to the object when go to X and we want
to say and because you know left is
lower and right is more in terms of x
coordinates we want to say -3 so I want
to move 3 pixels to the left ok and then
obviously we want to do the same thing
the other way around so if we go to do
this again go to keyboard add keyboard
right and then do the same thing again
jump to position relative X plus 3 ok
now if we hit OK and we run that
hopefully all going well which it has
eventually there we go we can now get
move left and right you can see the kind
of movement this creates for you it's
very very specific straightforward
method of movement because you are
literally moving 3 pixels every frame
that the game is detecting a left or
right input so that's that's literally
the simplest way of doing
so another way to move left and right
using this is to use these moved
move commands up here so if we get rid
of these now and we go to left and we
use a move move fixed with these arrows
on and we're moving to the left till we
want to take the left direction and we
set our speed to three this is slightly
different the way this works is
different let me just set the right
direction up exactly the same I have to
put minus in here because we're just
setting an absolute speed in a certain
direction so speed three going that way
the way this is different though is this
sets a speed that doesn't go away well
whereas before what we were doing was
moving the player object by a specific
amount every frame this is setting your
speed to be a certain amount and your
speed is add value that moves your
object every single frame by itself
until something makes that speed go away
so that means once we start moving we're
not going to stop until something causes
us to start moving which if you a basic
understanding of Newtonian physics will
sound kind of familiar to you and so
what we need to do is we need to create
a force of friction what that means is
the force that slows the object down
after it's started moving and causes you
to come to a halt so if we go to our
events and go to add event on creation
so that means when the object has just
been created and then this little icon
up here with the arrow turning into the
smaller arrow is our set friction action
so what we typically want our friction
to be a very very low value it literally
something like naught point like not v
or like maybe even less maybe a little
bit more test that value we'll see how
that works but I mean the reason you
this is a very small value is because
what friction does is friction literally
reduces your speed by this amount every
single frame of the game while your
speed is not zero so if your speed is
like minus two and your friction
is say 0.5 it'll go from minus 2 to
minus 1 point 5 to minus 1
- no - not 0.5 to 0 like over the course
of like 4 frames whereas like if your
speed was - it would go from 2 to 1
point 5 to 1 - no point 5 to 0 you get
the idea so if we set our friction to
null point 5 and left and right set is
our speed to about 3 and we compile
again and then we have it we should be
moving left and right and now if I just
tap the key I start moving at 3 and then
the friction causes us to slide to a
hole it's a little bit slightly at the
moment because you know you can play
with the values to get it to stop so
more firmly or more on point so this is
sort of a looser more sort of analogue
method of moving about so that's how we
move with the move fixed command however
what we are still doing with our move
fixed command is we are still setting
our speed to be a specific value as
opposed to slowly accelerating to that
speed as you know you might want for
however you want your game to feel so
you might want to slowly move up to a
speed as opposed to sort of instantly
selling yourself to move in a specified
speed so in order to create acceleration
instead of just sort of you know stank a
movement value what we need to do is if
we go to these actions and we take this
relative box again again what this means
is we're setting the speed to basically
be three in this direction relative to
what your speed currently is so what
kind of adding three to your speed as
opposed to we're adding a speed of 3 and
the left to your current speed as
opposed to just setting your current
speed to be 3 in that direction of
course 3 would be way too much to
accelerate viable so we're going to set
this to 1 and left and and the right
we're going to be the same thing 1 and
relative and now this would go
absolutely nuts um because we at the
moment we would accelerate left and
right by one constantly and the friction
is still the only thing slowing us down
so theoretically if we hold left for
like 10 frames
we're already moving
ten pixels a frame to the left so we
need to establish a maximum speed this
is where things get a little bit more
tricky but not really by all that too
much so I'm going to go to events go add
event and we're going to look at the
step event now the step event is I think
I explained before is literally an event
that just triggers every single frame so
every single frame of stuff in this this
action thing will happen to this object
so what we want to do here now if I can
find it is test here we go test variable
little circle circular type var thing
with the word var in it so what this is
is we're we're asking the game a
question right now we're going to ask if
the variables speed which is so as you
might have guessed represents is the
variable that we've been saying numbers
to with those actions and our left and
right event so we're going to test if
speed is greater than six so in either
direction like it doesn't matter what
direction you're in if your total speed
of your of our object is greater than
six we will carry out any actions that
follow from this this action so if speed
is greater than six that's all that's
the first action we're doing in our step
and after that if the speed is greater
than six what we want to do is set speed
to six so what that means is if you
would go above six so like the game is
trying like to move you at six point
five or just trying to move you a seven
or whatever we just settle speed back to
six so that that basically imposes a
maximum speed we can be below that but
we can't be above that and that's in
either direction so if s B is greater
than six set variable speed to six now
we might want to turn off friction up a
little bit because how it was before was
a little bit slide II so if we tunnel
friction up to two point two so that we
hopefully get a little bit of a better
slide to a stop let's see how that looks
yeah as you can see we're now
accelerating to a speed of a maximum
six and then when we let go of the burn
we slowly slide to a halt so we slide
stop and we slide to a halt that's how
you can create a kind of more sort of
sliding fluid movement the tio character
obviously it depends exactly on what
kind of failure you're looking to create
in the end but those are the sort of two
main methods of moving your character
around you're either jumping to a new
position every frame based on a based on
a value that you want your player to
always move on so just add like five to
your ex or whatever to keep moving like
five pixels a frame or what you're doing
is you're creating an acceleration every
time you're holding left or right and
then creating a maximum speed you can
reach and then creating a friction that
slows you down when you're not pressing
those buttons I mean this little extra
variance you could do in between so you
could have it so that when you you're
moving like this every time you're not
pressing one of those buttons you were
instantly like lose all your speed you
could just set your speed to be zero so
like if you want be able to come to an
instant stop and you don't want this
kind of sliding effect that we've got
going on then you could do that as well
if you still wanted acceleration but you
didn't want friction you know you can
use you and mix and match until you
create the feel that you want to feel
the feel that you want to feel well yeah
I guess that makes sense