GameMaker Studio: Drag & Drop Platformer Tutorial Video Lecture | Game Maker Tutorial: Build Games from Scratch - Game Development

alright God is how we doing this week
what I'm going to be looking at is some
well basically I've been a little bit
worried that maybe I've been leaving
some people behind that I've been
jumping a bit too far ahead with all the
kind of advance like GML coding kind of
stuff and like if you were following
along just using the drag-and-drop
options
you probably got left behind somewhere
in the in the top down shooter tutorials
so I'm gonna go back and just basically
explain how to recreate the platformer
from like my index platformer tutorial
or how to recreate something mostly
similar mostly the same sort of thing
just using the drag-and-drop commands in
case you know you know you're not really
ready to get straight into the code yet
and oh you're just you know you're
trying to make up some quick prototypes
and stuff for your game and you're not
you're not looking to create anything
that's super complex or polished or
whatever you know right away which is
perfectly fine so I'm gonna just be
taking a look at how how we can still
use you know all the drag-and-drop
options use some of the ones we haven't
used yet and that kind of thing and you
start to see how you know you can build
things like a platformer with it so as
you can see over here we've got a got
the setup that basically what I started
with for um my in-depth platformer
tutorial which you know once you're more
comfortable with the code um you know
once you you're prepared to step into
coding you know you can go go watch that
and see how you know you can take direct
control over these sorts of things but
yeah we basically just have the same
setup that we have in that tutorial um
we have a sprite for our player a sprite
for the balls and an object for the wall
and an object for the player with the
sprite setup as shown and I've just sort
of scared that around not onlys have any
code in them yet whatsoever the a
totally blank so I mean if we were to
run the game right now all that's going
to happen is No
right so these just sit here nothing's
going on so one thing we're going to
want to do is because we want to use
these walls we're going to take this box
over here called solid which basically
turns on some sort of automatic kind of
like collision system um within
GameMaker in it that tells the game that
this object is a solid wall and we'll be
using that in a little bit so the very
first thing we want to do is make it soo
our player actually Falls and there's
some gravity in the scene so what we're
going to do is now what we would
normally do I suppose what a lot of
people would do is a normal valid ways
of making this work is do something like
go to create and use set the gravity to
set up a gravity you specify the
direction of down as being like 270 foot
down and you know give yourself a
gravity that way I don't like using this
gravity the reason why I don't like
using gravity like this is because
gravity the built in version and
GameMaker it operates by applying a
speed a vertical speed to your character
every single frame and it does that
after your step it then which I don't
really like the reason I don't like that
is because you can do all your speed
calculations in your step event and do
your collisions and work them out all
properly but you have to basically every
time you land on the surface you need to
turn this gravity back off
whereas I prefer to have my gravity
system on all the time and you know let
you know as it is in reality and you
know I never actually need to turn it
off
because if you don't turn it off you
know you do all your speed calculations
and stuff and you you say right collide
with this wall and start moving and you
stop yourself moving you set your
vertical speed to zero but then your
gravity is applied after your step event
so you start to fall into the floor so
if you've ever tried to just mess around
with the actions and stuff and set up
gravity and you know build collisions in
what would seem an intuitive way
you notice you're player always just
constantly Falls really slowly through
the floor then you know now you know why
it's because gravity is applied after
after the step of then which I don't
like we can create an equivalent of
gravity
super super easily without using
creative and all we need to do is create
in the step of then use this action over
here which is set the vertical speed and
if we set on to relative it'll just add
this vertical speed on to our current
vertical speed every single frame in
other words it'll do exactly exactly
what gravity does so if we just set the
speed on or point six or not point nine
six yeah that'll do that will you know
apply vertically every single frame if I
run the game now you'll see I'm falling
falling faster and faster and so on
Newton is a bit slow one point six we'll
try that maybe might be a bit fast well
as fast but you get the point
yeah so basically that set the vertical
speed relative and a small number in
here does the exact same thing as saying
the gravity only it happens exactly when
you tell it to and it doesn't happen
like after you're just ever bent and
stuff like that so without actually
coding that you know and that gives you
a little bit more control over you know
when your gravity happens just slowing
you're creating a game logic you don't
have to turn your gravity off you can
just set your vertical speed to be zero
when you're on our floor or something
you know it just makes things like that
a little bit easier alright so now that
we have some gravity for a player the
next thing we want to do is make it so
he actually lands on the floor in order
to do that we're basically going to
check every single frame to see if just
below is an on line actually sorry we're
going to check to see if the place we're
going to be next frame vertically if
there is a collision there so if we were
moving up we would check basically a
little bit above us and if we were
moving down we check a little bit below
us to see if we're about to have a
because and I explained this in my
in-depth platformer tutorial how you
want a handle collision logic generally
or how I most prefer to handle it
you don't have to handle it this way it
might not be the best way you know I
don't know everything but the way I
prefer to handle collisions logically in
my head is to say if I am about to
collide with something move as close as
possible to that thing but don't but
stop just before I would collide with it
and set my speed to be zero how a lot of
collision systems might work is to say
if I'm currently colliding there so I've
I'm already overlapping the object
push me back out and I don't like that I
don't I don't like to create a system
that sort balances you out of an object
when you've already collided with it I
prefer to stop the collision from ever
technically happening in the first place
by saying if I am about to collide with
this object then move as close as
possible to it to land on it and then
you know set my speed to zero so that's
what we're going to do over actions as
soon as I can find it
this one over here in control a little
arrow pointing towards a little white
line sideways not to be confused with a
different one that we'll use in a minute
which is an arrow pointing downwards
still white light so the arrow pointing
to the right or this little white line
drag that over here this is our check
collision action so what this does is
what I just said it's going to check a
given set of coordinates to see if there
would be a collision with our object if
our object was at these coordinates
would it collide so what we're going to
say x and y to be zero and be speed so
what that means is it's going to check
on tic relative at the bottom here so
these are related to our current X Y
coordinates so what that means is it's
going to check X a relative zero so
exactly horizontally on the screen
exactly where our object currently is
so whatever my objects x-coordinate is
and whatever our y-coordinate is up and
down on the screen in plus whatever our
vertical speed is which is represented
by V speed you'll know if you've seen me
doing code and stuff now you'll realize
from this that you can use the built-in
variables in the actions like this but
if you type V speed into here well that
does is will pull your objects vertical
speed out and it'll it'll basically ask
ask the game for your current vertical
speed which we already set with our like
gravity and stuff is what we're adding
to that's how we get that number so so
if we were falling at say four pixels a
frame what this will do is it'll check
our position and four pixels down from
that position it's going to check there
to see if that would be a collision
objects stick only solid so it's only
going to check for things like our war
which are set to solid and then hit OK
now you'll see these little sort of you
know circular actions like this which
are questions and link so they're you
know they're asking the game a question
that they're checking to see if
something is true basically if that
collision is true then it's going to
carry out whatever the next action isn't
here so if I were to do something like
create an instant I mean since there's
no reason why we would do this but like
if for example like you know we check if
there's a collision then create a wall
somewhere this is just to make an
example we don't obviously want this
piece of code is that it will say if
there's a collision there then do this
and then if we have more actions
underneath it's not going to say if
there's a collision there do this and
this it's just going to say if there's a
collision then do this then regardless
do this so it'll only do it will only do
the next action by itself if we want the
question if it happens to be true so you
know if there is a collision here if we
want to do multiple actions which we do
we need to go into control and use these
arrows
here which create a start of a block and
an end of a block and these allow you to
group actions into one well block so if
we start to put our actions inside just
by dragging and dropping and it'll say
if there is a collision at position and
start of a block and then it will do
everything until it sees end of a block
if that happens to be true and if it's
not true it'll skip this block and we'll
do or whatever happens to be underneath
it so remember if you are asking a
question if you're doing the question
sort like a circular drag-and-drop
action icon then if that question is
true it returns true or any way you know
that is a collision or you know if there
is a certain number of instances or you
have pressed a button you know and so on
so forth it will create it sorry it will
do whatever the next line is unless you
use blocks in which case it'll do
everything inside the block that follows
it so now that we know whether or not
there's a collision obviously we don't
want to create a wall it's just an
example what we want to do is as I said
move as close as possible to the wall
that we would collide with now there's
actually a drag and drop operation built
specifically for this you go to move
over here the little downward arrow I
mentioned it earlier pointing to wall to
white line that's the one we need now
you drag that into your block and it's
called move to contact which means it's
going to move your object as close as
possible without to the object without
actually colliding with it well it's
going to move it in a given direct yes
is going to move sorry this task is
going to move your object in the
direction that you set here until it
collides with an object so basically
we're going to say move to contact in a
direction direction oh what that means
this is gonna move us in the direction
that we're currently facing so like so
if
movingly get a little bit diagonal and
stuff it or whatever basically if it's
we're just going to move in whatever
direction we're currently moving which
is appropriate since we checked if
vertically we're gonna hit something
we're going to set the maximum just to
be 5 because there are some other little
bugs and quirks of this system if you
have maximum or minus one would
basically mean that there is no maximum
and all new viewers as close as that
needs to but there are a few little
quirks and eBooks because we're using
the direction of direction and sometimes
if you like walk off of a corner you can
seemingly teleport you to another war so
just to sort of ward against that again
this is sort of just a little prototype
engine for you really it new it does
have a few little quirks and then go
better though if we set maximum to 5 it
shoot me more or less get rid of those
little kinks and then again solid
objects as we said so it nervous to find
our or object wall you know basically
movers a maximum of 5 basically just put
whatever your current your maximum speed
happens to be we don't actually have one
set with our vertical speed technically
how gravity can go on forever but
typically you would set something up to
limit your speed too young or
ridiculously fast ever and then your
maximum would appropriately be whatever
that happens to be so move the contact
in direction direction then the next
thing we need to do also moved as close
as possible to the wall vertically or
the ceiling is to basically reduce
orbital speed to zero because we've hit
the wall so basically we just use this
the big white dial error again we're
just setting a vertical speed we don't
need to take relative this time and just
have zero so it'll just settle vertical
speed to absolute zero and now hopefully
if I run the game can you can see boom
we land on land on the floor it was a
bit quick but hopefully you can see that
it just Landers boom on the floor
because it he moved faster and faster
and faster and then he saw he was about
to hit the floor he moved as close as
possible to the floor on a pixel perfect
look
and and then a speed has been set to
zero so now he lands on the floor that's
fantastic
the next thing we want to do is
basically set it up so that he can
collide horizontally as well as
vertically basically we just do exactly
the same thing we've already done so but
we use H speed and stuff in horizontal
speed to to do our checks so again if we
go down to control and we do a check
collision and we're going to say applies
to self and we're going to just say X H
speed Y zero relative objects only solid
all the same reasons as before but
instead of we're checking exactly where
we are vertically and we're checking
exactly where we are plus our current
movement speed either right or left so
it'll be like minus four if we're going
left or plus three if we're going right
you know it's going to add that number
is going to check that position the
position we're about to be in next frame
to see if there's a collision
horizontally I got those in the right
order yes I am I'm putting this one
above the vertical check there's a
reason for that
the reason you want to check horizontal
speed first in terms of likely or logic
order as opposed to vertical speed is
just for the odd case where like say you
hit a perfect diagonal you want to say
like in like if you were falling toward
the platform and like you're about told
you about to move into it perfectly
diagonally you basically have to make a
decision in your game about whether
they're not whether or not that means
you land on the platform or whether or
not that counts as hitting the wall and
falling and obviously it feels a little
bit better to play if you say you land
on the platform which means you want to
check your horizontal collision first
because it's going to see oh there's
nothing in front of me
move me horizontally and then check
below you and say oh there's a floor
below me land as opposed to if you do
vertical first because it would say oh
there's nothing but
we move vertically olders now a wall in
front of me don't move horizontally and
you would miss the platform so that's
the only reason why I'm going to do
horizontal in front of vertical so now
we've got a second collision check setup
or what we want to do is just create
another start block and another end
block right then just so that we can
create some actions for what happens if
we're about to collide horizontally and
then again we just do this the same
thing we'll go to move and we say move
to contact a direction direction maximum
of five and against solid objects okay
and then we want to set our horizontal
speed to be zero simple as that and now
it'll be move that to that there we go
the thing we want to do now of course is
set up so we can actually move because
at the moment we can't actually move
left and right so there'd be no way to
actually demonstrate that this
horizontal speed is even working so in
order to set that up I'm going to come
over here and add an event for keyboard
for whenever the left arrow key is
pressed now
when the left arrow key is pressed what
I'm going to do is I'm going to take set
our horizontal speed e - naught point
five and we're going to say that that's
relative so it's going to constantly add
negative nine point five to a horizontal
speed whenever we're holding left so at
the moment we can speed up to infinity
obviously not what we want so I'm going
to give ourselves a maximum speed I'm
going to do that as I'm going to go to
control no I'm not yes I am and grab
this question mark over here and it's
going to say if an expression is true
now this is quite powerful action that
allows you to check like any like
variable and looking in the game or
whatever to see on a check check like
any like mathematical function if you
values like Excel and you've done sort
of like an if statement or something in
Excel to see like if like B 22 is bigger
than
you 29 then color the cell green or
whatever it's that same sort of concept
so what we're going to do is we're going
to say if H speed which is a horizontal
speed is greater than minus five so if
our horizontal speed is bigger than nine
is 5 which means like it could be minus
four or it could be zero or it could be
like three if you're moving to the right
or whatever and then because we've got
that and as I explained to you with a
circular icon over here how this works
is it's going to say if that's true then
do this thing and if it's not true it
won't it won't do this thing if we
wanted it to do multiple things again we
would use like a start block and an end
block and put a bunch of actions in but
we don't we just want to do is one thing
so you know that should be perfect we
find out and hopefully if I run the game
we should demonstrate like I've landed
on here and I can move to the left and
collide with that wall so we're getting
there okay we've got gravity and we can
move to the left and we can land on
platforms we're almost there so what we
want now is just I'm going to copy and
copy what I've just done and basically
just do the same thing for moving right
so I'm going to test an expression again
and say if I hate speed this time is
less than five because five horizontal
speed whoops beam is moving to the right
at five pixels a frame or whatever
so if our horizontal speed is less than
five then and and the reason I'm doing
this expression is testing this
expression is to set a maximum speed so
when we're moving to the left we can't
go more to the left than minus five
pixels the frame and when we're going to
the right we can't go more to the right
than five pixels a frame because it has
to be less than five so then we're going
to go to move set horizontal speed and
we're going to set that to not 0.5
relative if we press right same as what
we did for left only is positive instead
of negative
now we can move left and right fantastic
and you'll notice you slowly speed up as
well like like that the moment you slide
infinitely if you let go of the button
so what we're going to do is go add
event create and we're going to add and
you'll be familiar with this if you've
seen any of the coding stuff as we're
going to use set friction which you're
sets up a value that will reduce our
speed every single frame and we're just
going to set that to be something really
small and more point not to and then
hopefully I won't move left and right
okay we could do a turning that up a bit
maybe not point to there we go so now
when we move left and right we slowly
kind of slide to a hole it's very very
slide II at the moment there were a kind
of a Mario feel but um you can play
about with those numbers to get a
feeling exactly kind of how you want so
yeah so now we're setting off friction
what we want to do now is be able to
actually jump so we can climb around
this platform level so what I'm going to
do is go over here and add an event this
time I'm going to use a key press event
instead of just a key event and say
shift just so that when we're hard you
know we don't jump by holding shift we
jump by it by pressing shift so use
press shift so it only detects it once
when we first press it and only carry
these kind of things out again if we let
go of the button and press it again now
what we're going to do is just set our
vertical speed to be minus minus eight
for example it's - because we're going
up if it was positive it means we're
going down we're just going to set that
to be like minus eight so if I says now
and I press shift you'll see were able
to jump that's pretty cool
but at the moment there's nothing
stopping those mashing shift and just
jumping you know forever drumming in the
air
so we need to say that we can only jump
when we're on the ground and the way to
check were for not around the ground is
to basically use a collision check like
we've been doing in here and we're going
to go to control and say in questions
drag this check collision action and
we're going to check X we're going to
say relative again so at the moment this
means this being zero means it's
checking exactly where we are but we
want to take just below us I'm going to
check one pixel below as y1 exactly one
pixel below where we currently are to
see if there is a solid wall only solid
so if there is we should be allowed to
jump and if there isn't and we won't get
a jump so now if I run the game press
shift and hear me mashing it there but
you know I'm not not floating off into
the sky so there you go there's a
functional system for making our
platform a simple platform little engine
game whatever you want to call it in
using just the drag-and-drop actions
that could well be a few little bugs and
quirks with it and stuff I haven't you
know super leaf thoroughly tested it or
anything like that you know it's not my
area of expertise I don't use the
drag-and-drop options a lot but
hopefully there i've been able to sort
of show you kind of a bit more about how
they work and how you can use them a
little bit more complicated ways because
they are still useful and they still you
know do give you a lot of power
flexibility and all of that and then
when you know perhaps navy later down
the line you're ready to move on to you
know learning some scripting and
learning a little bit of code you can
look at my in-depth platformer tutorial
which shows you how to create basically
everything we've created here but
step-by-step explained line by line
through the GML code entirely up to you
now the choices there so yeah I hope you
guys totally enjoyed that I have a
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yep so that's everything for this week I
hope you guys found that super useful
and I will catch you guys whenever I
catch you guys probably next week yeah
I'm gonna say next week see you guys
next week in a bit