How to make a Video Game in Unity - MOVEMENT (E03) Video Lecture | Build a Game: Unity Tutorial (English) - Game Development

hello everyone in this video we'll make
up play a move to do that we'll have a
look at variables if statements and
player input so if you want to make
games in unity this video is pretty much
essential I'm ready are you ready let's
go before we get started I just want to
mention that you can now download the
project files and the scripts from each
video over at dev assets so if we go to
dev assets comm this is a website I
created where you can download really
high quality 3d models such as this
Western props pack we have a modern
weapons bundle some cool-looking sci-fi
vehicles and a lot more if we go to
browse scroll down to the bottom here
and click how to make a game we get to
this page where you can download all of
this stuff I've seen the love tutorial
makers make their project files paid but
I don't really think that's fair to you
guys
instead as with everything on the site
here I've made it pay what you want so
you can of course go ahead and grab it
for free or choose to support me with
some amount you can just click the one
that you can afford here and then hit
the blue button and you're good to go so
back to the video in the last one we
made our cube fly forward by adding a
force right now a primary issue with
this is that our player doesn't stay on
the ground he just starts rotating and
jumping and goes crazy one way to fix
this is to go to the player find the
rigidbody and add some constraints we
could for example freeze the rotation on
the x-axis and that should result in
smooth movement however we do want our
cube to be able to rotate so that when
he collides with something it's going to
there cold let's uncheck that and
instead let's create a physics material
the reason for the cube jumping around
is that by default that's friction
between the cube and the ground by using
a physics material we can choose how
much friction we want let's right click
in the project go create and then select
physic material we can rename this to
something like slippery and we can set
both the dynamic and the static friction
to zero then we can drag this on torque
round and you can't see it being applied
but if we go ahead and select our ground
we can see that the material under the
box Collider is now set to slippery that
means that if we hit play now there's no
friction between the cube in the ground
and he's just going to slide off and
that's without restraining his rotation
so if we now select the player and
double-click on a player movement script
on this line we're adding a forward
force of 2,000 and then of course
multiplied with time.deltatime
however it would be really really neat
if we were able to modify this value in
the inspector instead of just hard
coding this into the line to do that we
use variables
in c-sharp I like to think of variables
like containers just like you can store
items in a box you can store data in a
variable in the beginning we focus on
storing symbol values like numbers or
text but variables can be used to store
way more complicated data each variable
is given a name this pretty much just
means slapping a label on the container
so that each time we use that name it
refers to the data of the variable we
also have to specify what type of data
we want to store for status you should
learn and memorize the four fundamental
data types integer we just write int
this store is a whole number
it can also be negative float this
stores the number with decimals string
this stores a piece of text and boolean
we just write full and this is the
simplest of all the data types because
it can only have two values true or
false so creating a variable looks like
this unity also allows us to edit a
variable in the inspector to do that we
mark it as public however this variable
is currently unassigned it has no value
we can assign the variable a default
value by simply typing equals and then
the value to get the value of the
variable in code we simply write its
name like here where we are printing the
value 10 to the console we can of course
also edit the value of variable here we
set it equal to 5 and here we add one on
to the current value making it 6 so if
we want to turn this number into a
variable that we can edit in the
inspector we'll go up here and create
some space will write public float
because we want a number that we can
fine-tune with decimal places then we
need a name in our case we could do
something like forward force and we can
set a default value in our case we'll
just set that to the same 2,000 then we
can substitute this number with forward
force so we'll just take the forward
force here and paste it down there if we
now say go back into unity we can see
that we are now able to adjust the
forward force in the inspector we could
set it to 4,000 or to a thousand if you
click and drag on it you can even find
cheerin like this and you can even edit
it while playing so now of course we
need to change this comment here instead
we'll change it to something like add a
forward force and it's time to have a
look at doing some player input now the
fundamental thing to understand when
doing play input is the if statement if
you make some room beneath our add force
method here we can write if open a close
the parentheses and then open and close
some curly brackets this is the basic
structure of an if statement if
statements allow you to
the execute code if a certain condition
is met this is where you put your code
and insert these two parentheses is
where you put your condition sometimes
it's really simple say comparing two
numbers we could write if 3 is bigger
than 2 of course this is always going to
be true and so this will always be
called we can also say if 3 is equal to
2 and this is of course false so this
code will not be called we can also
write other stuff say if 1 is equal to 2
minus 1 and this is of course true or we
could put not equal to you and now it's
false but this is only the stuff we can
do with numbers we can also put other
stuff in here if we want to check if the
user is pressing a certain key on the
keyboard
we'll go input get key and here we'll
also open in closer parentheses and in
here in quotation marks we write the key
we want so in our case we want D to go
to the right and now everything we put
inside of these two curly brackets it's
only called when the user presses D so
we could of course just go ahead and add
some more forces here let's say our be
done add force and in this case we don't
want to add a force on the z axis we
want to do it on the X meaning right and
left so we can go in here and add some
numbers say 500 will then do C row on
the Y and Sewer on the Z remember to
close it up with the semicolon of course
we want to multiply a 500 with time that
out of time just like we do up here if
you now save this I just set the forward
force to something pretty low just so
our cube doesn't go flying off we can
hit play and we should see that when we
hold down D our cube will indeed move so
we can go back and add this to the other
direction as well to do this we simply
copy our code paste it right beneath
instead of checking for the D key we'll
check for a and we still want to add a
force on the x-axis but we want to do so
in the opposite direction so we'll just
input a minus here again we can save
this play the game and see that we can
now move in both directions in fact why
don't we go ahead and make our movement
speed adjustable in the inspector it the
same way we did with forward force to do
that we just add a new public float up
here and we'll call this something like
sideways force let's just default that
to 500 by the way when we're dealing
with float variables you will notice me
writing an F at the end of the number
this just signifies that we're talking
about a float number in some cases we
can leave it out like here but other
times unity will complain so it's a good
idea to get in the habit of just doing
it every time again this only applies to
floats
not
integers so now we can take our sideways
force and paste it instead of the 500
here and instead of this 500 here as
well you'll notice that it's still fine
putting a minus here when we run the
game this is just going to be equal to
500 or what we said in the inspector
let's save this go back into unity and
we can now see that we can adjust the
sideways force as well let's try setting
the forward force to something like a
thousand and the sideways force to
something like 600 and it already starts
to feel like a game if you were able to
follow along with this really good job
programming the movement of the player
is definitely not the easiest thing that
you can do in unity and so it's always
annoying that it's really the first
thing that you have to do in most cases
but I hope you learned something and
remember you don't have to understand
and definitely not remember all of this
the first time I will just mention that
the way that we're handling player
movement here is not the most efficient
way but no one expects you to write
perfect code right off the bat I just
want to let you know how this could be
improved there's two main problems here
the first one is how we're getting
player input now using input dot get key
here is totally fine and in our case it
works perfectly but as soon as we want
to do stuff like smoothing player input
supporting alternative keys or maybe
even a controller unity has some much
better ways to handle the player input
so you can definitely look into that if
you want to improve it also we're
currently checking for input inside the
fixed update well it's fine in our case
because what we're doing is movement and
that's usually a fairly smooth thing
it's definitely not a good idea to do
for stuff like jumping or the one-off
events the reason for this is that input
is updated in the update method and if
the fixed update runs slower you might
have a situation where you actually miss
some player input first that would just
mean that the input gets slightly
delayed and that's why I think it's fine
here but the recommended thing to do is
check for an input in the update method
then store that input in some sort of
variable up here in our case that could
just be two boolean called something
like move right and move left that you'd
set it true if the keys pressed and
false if the keys released and then
check if those variables are true or
false down here to add a force but it
really wouldn't worry too much about
that right now
so let's pretty much it for this video
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definitely leave a comment and I'll see
what I can do so thanks for watching and
I will see you in the next video thanks
to have the awesome people who donated
in January and especially thanks to
Derek heaps Kirk face O'Meara Phi James
Calhoun Robert Vaughn and Peter Locke
and Jason dirt-eater
if you want to
come a picture in yourself you can do so
a pitch intercom / brookey's thanks
about guys