WEBVTT

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Game Advanced
Prototype 2

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GCC Academy

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Hello

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I'm Youngho Lee, and I'll be leading the lecture on creating shooting games

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In this lesson

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we'll cover the second part of the prototype

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First, we'll understand vectors and use them

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to move the player based on the uniform motion equation

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Then, we'll implement movement according to user input

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Understanding Vector

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Let's start by understanding vectors

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First, I'll create a simple sample code

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We'll write code where

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the player keeps moving to the right

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To achieve continuous movement to the right

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We'll use the following code

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Transform

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Translate

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Vector3.right* 5* Time. deltaTime

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I'll write this down

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By doing this, we're implementing the idea of the player

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moving continuously to the right

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We put the content in Korean first

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Now, if you look at this code

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you'll notice it's placed in the Update function rather than Start

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The reason is that the code needs to be in the Update function

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when you want something to keep happening

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while the game is running

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After saving this

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let's go ahead and test it out

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When you press the play button

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You can see the player continuously moving to the right

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This is made possible by the line of code we just wrote is essential

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To grasp this fully, we need to explore a few concepts

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Let's start by looking into vectors

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and then dive deeper into the code

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First, what exactly is a vector?

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If you look at its structure, it's represented as an arrow

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This arrow has a body

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I'll call here body, and this tail

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I'll say "tail," and a "head"

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The blue part of the arrow represents its magnitude

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and the red arrowhead

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indicates its direction

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A vector is an element that combines

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these two components

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Magnitude and direction

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This one which always includes both

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We call it a vector

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Vectors play a crucial role

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when we want to express

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physical movement

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They're used for simple mechanics like moving objects

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Also

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Simulating interactions like light hitting a surface, bouncing off

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and reflecting

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All of these processes

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rely heavily on vectors

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For instance, if you look at the arrows

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on the screen representing the direction of light

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They're vectors

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By understanding vectors thoroughly

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you'll gain a solid foundation

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for working with

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Unity to create games

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Now, let's take a closer look at the various characteristics of vectors

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Vectors are typically represented as arrows

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and they can undergo arithmetic operations

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These operations include

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addition, subtraction, multiplication, and division

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Right?

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However, in the context of vectors

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we primarily use multiplication and division

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When it comes to multiplication, there are two main types

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Dot Product

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It is represented with a dot and used for certain calculations

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Then, Cross Product

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It's used like this

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Since it's a dot, we call it Dot Product

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and this one with "x" symbol

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So we call this Cross Product

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In Korean, the dot product is called 'naejeok'

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and this is called 'woejeok'

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What we have to focus on is

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addition and subtraction

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These are really important

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to do the work

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And these two

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are used variously

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The dot product is a multiplication operation

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between two vectors

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that results in a single numerical value

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As we mentioned earlier, vectors consist of magnitude and direction

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The resulting value from a dot product

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is called a scalar

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A scalar

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When you perform a dot product operation on two vectors

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each defined by magnitude and direction

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you obtain a scalar value

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Next, this Cross Product, the outer product

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When you do the outer product of two vectors

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a vector perpendicular to these two vectors

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pops out

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We call this the outer product

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The two vectors are used for very important roles

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depending on their purpose

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This time, we will learn about

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addition and subtraction

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Then, the important thing is how addition is used

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Let's assume that there are two vectors

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Let's take a look

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Here is the vector of A

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and then here is the vector of b

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The vector of A can be placed here

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and on top of this

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This vector has a magnitude and a direction, right?

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In other words, it does not include a location

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Let’s think of vector A as wind

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The wind blows continuously

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It's blowing like this

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It doesn’t only blow

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between specific points

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When you open a window, how does the wind flow?

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It simply comes in

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regardless of its position

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When I'm there, the wind comes in like this

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So, it doesn't matter where it is located

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So whether you put it here or here

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it blows like this

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So, it doesn't matter

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if I put the position of A here, this vector of A, right?

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Now, let's imagine you press both the right arrow key

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and the up arrow key

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So what happens if the plane hits both

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at the same time?

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If you look at the last picture

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you can see that it has to go diagonally

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In other words, if you add the two vectors if you connect the endpoints like this

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you get a vector

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that points to the last two points

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Vector addition works like this

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It represents the sum of

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all forces acting on an object

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Let’s take an example

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Imagine we throw a ball

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Like this

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If we throw it

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will the ball

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fly infinitely in one direction?fly infinitely in one direction?

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Will it even go through the Earth?

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For real?

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No, it follows a curved path, a parabola

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and eventually falls to the ground, right?

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In a typical scenario, it will fall due to gravity pulling it downward

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Why?

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Because gravity acts

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How does it work?

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It acts downward

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So, if you add these two arrows

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It goes like this

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It doesn't happen like this

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Gravity gradually affects my force, so what happens?

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This one goes like this

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and it goes in a parabolic motion

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So vectors can express the sum of all forces

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when adding

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If the wind blows in the opposite direction like this

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And gravity is also at work

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If you add them all up, how do you think the ball will fly

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when the wind is very strong?

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It flies like this, and then, because of the wind

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it returns like this

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Right? You can direct it like this

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So the wind is this force

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the force we threw is this force

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and the gravity that falls down

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When you add all these up, the object's final position is determined

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When you add all these up, the object's final position is determined

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I think it would be good to know that addition

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is used for this purpose

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Representative games include baseball, golf

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and billiards

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You can think of all of these as using addition to this vector

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How do we use subtraction?

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In the end, subtraction is also a part of addition, right?

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If we have A, we can subtract it by adding its opposite

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So, while subtraction is technically an addition

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its purpose varies

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depending on how we use it

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Let's say we have vector A here and vector B here

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If we subtract A

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what happens?

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Interestingly, subtracting A flips its direction

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That's because

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When negative numbers and minuses are multiplied

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What happens when -1 is multiplied?

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That is, the direction of the vector can be changed

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Right?

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Now, if vector A points this way

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and vector B points this way

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how do we find

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the resultant vector, like in addition?

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The final vector would look like this

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B - A, how does it come out?

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It comes out like this

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How do you know this then?

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It's like A wants to move to B

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So, you can see vector subtraction like this

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How is it used?

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Imagine you are here, and your target is over there

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You want to go toward the target

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I want to go in the direction of the target like this

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So, our goal is to find this vector

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How do I do this? Where do I want to go?

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I want to go in the direction of the target

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Let's call this vector the direction

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So how do I find this Direction, this vector?

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It's Target - Me

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I find it like this when I want to

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go to the target

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Target - Me means

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I can see the vector from me

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to the target, the destination

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Okay? This is how I can find it

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Let's find out one more thing here

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Let me draw this on a graph

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Let's put it

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like this in rectangular coordinates

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Here's the X-axis, right? Here's the Y-axis

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It's like this

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Let's move it over here so that it's easier to see

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Then, if you look at it

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I'm here, and the target is at this point

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How about looking at the two positions like this?

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From here to this point

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 let's call it x1

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Here's x, here's x1

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Then, at this point

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let's call this Y1

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In other words, let's say this vector is added

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If my position is at this point

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and if I add this vector to my position

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where am I ultimately?

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I'm at the target position

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Then, if I'm standing here

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and this standing character moves to that side

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if I add this vector

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it'll move like teleportation, right?

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This isn't the type of movement we want

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What do we want to do?

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I want to go like this at my speed

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In that direction

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Then, I told you that this vector

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comprises magnitude and direction

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Then I don't need this magnitude

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I just simply need this direction

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and I'm just going to move this character

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in this direction

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Then

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I said that it comprises magnitude and direction

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I wrote multiplication here

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At that time, I only needed direction

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So I'm going to have my movement speed

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I'm going to multiply my speed here

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Then the vector's magnitude

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doesn't simply becomes something

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But I want it to be like this

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So I want it to move this much at my speed

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Then, what if this vector we got by subtracting vectors

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becomes specific speed, it's my speed

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This is me

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Will only my speed and direction remain?

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What should this magnitude become?

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It should be 1

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So this action of making the magnitude of this vector

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this direction

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from Target - Me 1

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is called vector normalization

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In English, it's called Normalize

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00:15:31.870 --> 00:15:34.119
That's what it means

281
00:15:34.119 --> 00:15:37.969
This is the action I take when I want to move at my speed

282
00:15:37.969 --> 00:15:39.559
with this vector

283
00:15:39.559 --> 00:15:42.039
that I got by subtracting vectors

284
00:15:42.039 --> 00:15:45.280
At this time, vector normalization is used

285
00:15:45.280 --> 00:15:50.159
Then you guys will make a game

286
00:15:50.159 --> 00:15:52.679
Let's say it's an MMORPG game

287
00:15:52.679 --> 00:15:57.280
I clicked here with the mouse pointer

288
00:15:57.280 --> 00:15:59.320
I clicked here like this

289
00:15:59.320 --> 00:16:01.970
Then, the character should stand here

290
00:16:01.970 --> 00:16:03.599
and move in this direction

291
00:16:03.599 --> 00:16:06.239
Then how do I do it?

292
00:16:06.239 --> 00:16:11.080
My position, the position of the target that the mouse clicked, will be found

293
00:16:11.080 --> 00:16:15.119
If I do  Target - Me, this vector will be found

294
00:16:15.119 --> 00:16:18.280
Then I will move in this direction

295
00:16:18.280 --> 00:16:20.039
In something like an MMORPG

296
00:16:20.039 --> 00:16:21.828
Then, instead of just adding this vector

297
00:16:21.828 --> 00:16:24.531
you have to normalize it

298
00:16:24.531 --> 00:16:27.239
to make it fit into this vector

299
00:16:27.239 --> 00:16:30.320
In other words, if you make it into a normalized vector like this

300
00:16:30.320 --> 00:16:32.970
you can move in that direction

301
00:16:32.970 --> 00:16:34.719
at your speed

302
00:16:34.719 --> 00:16:36.960
This is called normalization

303
00:16:36.960 --> 00:16:39.060
So vectors are largely

304
00:16:39.060 --> 00:16:42.760
divided into addition, subtraction, inner product, and outer product

305
00:16:42.760 --> 00:16:45.410
but this time, we only looked at addition

306
00:16:45.410 --> 00:16:48.520
and subtraction

307
00:16:48.520 --> 00:16:56.559
Then, in this sentence we mentioned earlier

308
00:16:56.559 --> 00:16:59.359
in the part where the player goes to the right

309
00:16:59.359 --> 00:17:01.280
there's a part that says Right here

310
00:17:01.280 --> 00:17:02.930
This is a vector

311
00:17:02.930 --> 00:17:05.644
so it has the direction of the right side of the vector

312
00:17:08.080 --> 00:17:11.520
What is its size? It's 1

313
00:17:11.520 --> 00:17:14.159
What's the 5 at the end?

314
00:17:14.159 --> 00:17:16.599
That would be my movement speed

315
00:17:16.599 --> 00:17:19.149
The one behind, I'll talk about it again later

316
00:17:19.149 --> 00:17:23.520
is just the time used in uniform motion

317
00:17:23.520 --> 00:17:25.479
The time used in uniform motion

318
00:17:25.479 --> 00:17:26.520
So what?

319
00:17:26.520 --> 00:17:31.280
That's the vector I created

320
00:17:31.280 --> 00:17:33.931
And the one behind is the time multiplied

321
00:17:33.931 --> 00:17:37.911
Understanding Constant Velocity Motion Formula 
and Player Movement Creation

322
00:17:38.919 --> 00:17:42.219
Then, let's learn about the formulas

323
00:17:42.219 --> 00:17:45.039
for uniform motion

324
00:17:45.039 --> 00:17:50.400
If you look

325
00:17:50.400 --> 00:17:54.000
it's about Newton's kinematics

326
00:17:54.000 --> 00:17:58.280
The first part is P = P0 + vt

327
00:17:58.280 --> 00:18:00.799
v = v0 + at

328
00:18:00.799 --> 00:18:03.320
The third is F = ma

329
00:18:03.320 --> 00:18:04.440
It goes like this

330
00:18:04.440 --> 00:18:06.479
The last one is F = ma

331
00:18:06.479 --> 00:18:09.840
It's probably ingrained in your DNA

332
00:18:09.840 --> 00:18:11.039
What about F?

333
00:18:11.039 --> 00:18:14.430
I don't know where you use it, but ma?

334
00:18:14.430 --> 00:18:18.400
The part that comes out like this is where it says F = ma

335
00:18:18.400 --> 00:18:21.400
So when an object moves dynamically

336
00:18:21.400 --> 00:18:24.661
or becomes like this by kinematics

337
00:18:24.661 --> 00:18:28.039
These three formulas are used

338
00:18:28.039 --> 00:18:30.919
That's why the physics engine embedded in Unity

339
00:18:30.919 --> 00:18:32.669
also uses these formulas

340
00:18:32.669 --> 00:18:37.440
to implement the parts where objects move

341
00:18:37.440 --> 00:18:40.400
The first of these is the formula for uniform motion

342
00:18:40.400 --> 00:18:43.559
Let's say there's a person here

343
00:18:43.559 --> 00:18:47.400
You guys push them from behind

344
00:18:47.400 --> 00:18:50.799
You push them with a bang

345
00:18:50.799 --> 00:18:54.760
What happens to this person then?

346
00:18:54.760 --> 00:18:56.760
If you push them from behind

347
00:18:56.760 --> 00:19:02.520
they'll get pushed this way

348
00:19:02.520 --> 00:19:03.840
Of course

349
00:19:03.840 --> 00:19:06.760
At this time, the shape in which the object moves

350
00:19:06.760 --> 00:19:10.119
is created by this formula

351
00:19:10.119 --> 00:19:16.559
First, let's put P0 as the current position

352
00:19:16.559 --> 00:19:18.239
of this person

353
00:19:18.239 --> 00:19:19.080
This is the current position

354
00:19:19.080 --> 00:19:20.440
Position

355
00:19:20.440 --> 00:19:23.520
Next, this is my future position

356
00:19:23.520 --> 00:19:27.443
Let's put P

357
00:19:27.443 --> 00:19:29.095
Next, there's

358
00:19:29.095 --> 00:19:31.520
the direction that occurred when the user pushed from behind

359
00:19:31.520 --> 00:19:32.960
This is an arrow

360
00:19:32.960 --> 00:19:34.400
What do we call this?

361
00:19:34.400 --> 00:19:35.320
It's called a vector

362
00:19:35.320 --> 00:19:38.359
Let's put V, which stands for velocity

363
00:19:38.359 --> 00:19:39.919
Velocity, V

364
00:19:39.919 --> 00:19:42.640
This is a vector

365
00:19:42.640 --> 00:19:45.754
So, this person doesn't move instantly

366
00:19:45.754 --> 00:19:50.152
but moves gradually over time

367
00:19:50.152 --> 00:19:52.840
That's why there's a T at the end

368
00:19:52.840 --> 00:19:57.719
So they move over time

369
00:19:57.719 --> 00:20:00.799
Let's take a look at this again

370
00:20:00.799 --> 00:20:04.000
I pushed from behind

371
00:20:04.000 --> 00:20:04.760
Did you?

372
00:20:04.760 --> 00:20:08.589
When you push this, a force is applied

373
00:20:08.589 --> 00:20:10.479
A force is applied

374
00:20:10.479 --> 00:20:12.719
The one in front is called uniform motion

375
00:20:12.719 --> 00:20:14.880
The one behind is called uniformly accelerated motion

376
00:20:14.880 --> 00:20:15.799
The last one below

377
00:20:15.799 --> 00:20:18.719
the force goes up to F = ma

378
00:20:18.719 --> 00:20:20.960
This also goes like this

379
00:20:20.960 --> 00:20:24.559
Now, what is A here?

380
00:20:24.559 --> 00:20:27.919
This part affects the current position

381
00:20:27.919 --> 00:20:28.760
which is velocity

382
00:20:28.760 --> 00:20:32.200
Velocity

383
00:20:32.200 --> 00:20:35.594
a is acceleration that affects velocity

384
00:20:39.039 --> 00:20:39.679
Okay?

385
00:20:39.679 --> 00:20:41.119
Here, m is mass

386
00:20:41.119 --> 00:20:43.719
The mass of the object

387
00:20:43.719 --> 00:20:49.799
So, let's put mass as 1 here

388
00:20:49.799 --> 00:20:52.359
Then what will F be?

389
00:20:52.359 --> 00:20:54.539
It will be a, right?

390
00:20:54.539 --> 00:20:57.080
I pushed from behind with force

391
00:20:57.080 --> 00:20:58.919
What happens then?

392
00:20:58.919 --> 00:21:01.435
a is created

393
00:21:01.435 --> 00:21:02.799
a is created

394
00:21:02.799 --> 00:21:05.280
Where does a affect?

395
00:21:05.280 --> 00:21:08.039
It is added to the current velocity

396
00:21:08.039 --> 00:21:10.679
so v0 is also the current velocity

397
00:21:10.679 --> 00:21:15.323
v0 affects the current velocity, creating a new velocity

398
00:21:17.679 --> 00:21:19.440
A new velocity is created

399
00:21:19.440 --> 00:21:21.799
and v has changed

400
00:21:21.799 --> 00:21:23.599
This part has been created

401
00:21:23.599 --> 00:21:26.730
So where does v affect?

402
00:21:26.730 --> 00:21:29.080
It adds to the current position

403
00:21:29.080 --> 00:21:31.559
and changes the future position

404
00:21:31.559 --> 00:21:35.885
So when you push from behind like this, force is generated

405
00:21:35.885 --> 00:21:39.119
Force means acceleration is created

406
00:21:39.119 --> 00:21:43.440
Then, by affecting this part, a new v is created

407
00:21:43.440 --> 00:21:47.320
Then, the structure that creates this structure

408
00:21:47.320 --> 00:21:49.119
where the player P0 moves to P

409
00:21:49.119 --> 00:21:53.310
can be seen as the formula for uniform motion

410
00:21:53.310 --> 00:21:57.359
Then, what are all the games

411
00:21:57.359 --> 00:21:59.400
or realistic content

412
00:21:59.400 --> 00:22:01.960
that we create?

413
00:22:01.960 --> 00:22:04.119
They happen in virtual space

414
00:22:04.119 --> 00:22:06.559
We simulate in virtual space

415
00:22:06.559 --> 00:22:08.919
To do that

416
00:22:08.919 --> 00:22:13.239
we have no choice but to understand the dynamics part of kinematics

417
00:22:13.239 --> 00:22:15.487
Games are ultimately about creating dynamics

418
00:22:15.487 --> 00:22:18.840
that are identical to reality, similar to it

419
00:22:18.840 --> 00:22:21.440
So we have to use this kinematics

420
00:22:21.440 --> 00:22:23.000
in our games

421
00:22:23.000 --> 00:22:24.960
The important thing here is

422
00:22:24.960 --> 00:22:27.960
the vector

423
00:22:27.960 --> 00:22:31.050
Then, if we look at the content a little more

424
00:22:34.030 --> 00:22:36.719
P0 that you see here

425
00:22:36.719 --> 00:22:40.191
is just the simple position of a certain player

426
00:22:40.191 --> 00:22:43.039
Position

427
00:22:43.039 --> 00:22:44.679
P is also just a position

428
00:22:44.679 --> 00:22:48.119
Here, t is a scalar value, time

429
00:22:48.119 --> 00:22:51.680
Here, v means this arrow

430
00:22:51.680 --> 00:22:54.359
So we draw a vector

431
00:22:54.359 --> 00:22:58.960
on the head like this, an arrow like this

432
00:22:58.960 --> 00:23:00.039
What is this?

433
00:23:00.039 --> 00:23:02.080
It's an arrow, a symbol for a vector

434
00:23:02.080 --> 00:23:05.640
a is also acceleration, gravitational acceleration

435
00:23:05.640 --> 00:23:07.200
The arrow is acting downward

436
00:23:07.200 --> 00:23:09.880
So, this is also an arrow

437
00:23:09.880 --> 00:23:12.880
F is also an arrow, a is also an arrow

438
00:23:12.880 --> 00:23:14.760
The m here is mass, so it's just the number 1

439
00:23:14.760 --> 00:23:16.359
A scalar value

440
00:23:16.359 --> 00:23:18.200
We can express it like this

441
00:23:18.200 --> 00:23:20.679
This is the formula for uniform motion

442
00:23:20.679 --> 00:23:23.829
We'll use this to create

443
00:23:23.829 --> 00:23:26.919
our player's movement

444
00:23:26.919 --> 00:23:28.760
Let's use this

445
00:23:28.760 --> 00:23:33.280
to create our player's movement

446
00:23:33.280 --> 00:23:34.680
If you look at the code

447
00:23:34.680 --> 00:23:37.520
this part itself

448
00:23:37.520 --> 00:23:40.959
this much in this part

449
00:23:40.959 --> 00:23:44.079
is v

450
00:23:44.079 --> 00:23:46.280
Why? What is P?

451
00:23:46.280 --> 00:23:49.040
P0 + vt

452
00:23:49.040 --> 00:23:51.440
This is a vector

453
00:23:51.440 --> 00:23:57.119
and v is a vector with magnitude and direction

454
00:23:57.119 --> 00:24:01.560
So V is created by multiplying direction × magnitude

455
00:24:01.560 --> 00:24:05.959
The t behind here is called deltaTime

456
00:24:05.959 --> 00:24:07.959
This transform.Translate

457
00:24:07.959 --> 00:24:11.959
This internally implements this formula

458
00:24:11.959 --> 00:24:15.927
which is the internal function of this translate

459
00:24:18.719 --> 00:24:21.319
So this deltaTime behind here

460
00:24:21.319 --> 00:24:23.359
means t

461
00:24:23.359 --> 00:24:26.880
So, let's take a quick look at

462
00:24:26.880 --> 00:24:28.421
what this deltaTime is

463
00:24:31.599 --> 00:24:35.119
Let's take a closer look at deltaTime

464
00:24:35.119 --> 00:24:37.880
If you look at the one in front

465
00:24:37.880 --> 00:24:39.959
and below

466
00:24:39.959 --> 00:24:43.079
this is a new PC

467
00:24:43.079 --> 00:24:44.920
I opened up a new computer and bought it

468
00:24:44.920 --> 00:24:47.160
I bought it with the latest graphics specifications

469
00:24:47.160 --> 00:24:49.119
memory, hard disk

470
00:24:49.119 --> 00:24:51.359
and everything

471
00:24:51.359 --> 00:24:53.119
The one below is

472
00:24:53.119 --> 00:24:56.680
a PC that's about 5 years old

473
00:24:56.680 --> 00:24:59.119
It wasn't bad then

474
00:24:59.119 --> 00:25:03.479
but it became very slow after about 5 years

475
00:25:03.479 --> 00:25:06.880
You see this dotted line on the graph above

476
00:25:06.880 --> 00:25:08.719
This graph shows

477
00:25:08.719 --> 00:25:12.839
how often a new PC can perform operations

478
00:25:12.839 --> 00:25:13.880
in 1 second

479
00:25:13.880 --> 00:25:18.680
So let's say this is 1 second

480
00:25:18.680 --> 00:25:22.160
How can a new PC perform in 1 second?

481
00:25:22.160 --> 00:25:24.160
When this object moves

482
00:25:24.160 --> 00:25:28.239
it can move one, two, three, or four times in total

483
00:25:28.239 --> 00:25:30.928
It can perform four spaces in 1 second

484
00:25:30.928 --> 00:25:34.599
And two times under

485
00:25:34.599 --> 00:25:35.319
Do you understand?

486
00:25:35.319 --> 00:25:37.479
You can do this two times

487
00:25:37.479 --> 00:25:41.160
and let's say this character can move

488
00:25:41.160 --> 00:25:44.119
1 meter each time it moves

489
00:25:44.119 --> 00:25:46.886
Then the new PC above

490
00:25:46.886 --> 00:25:48.319
moves four times

491
00:25:48.319 --> 00:25:50.160
so it moves 1m each time

492
00:25:50.160 --> 00:25:54.719
So how many meters can it move in 1 second

493
00:25:54.719 --> 00:25:56.599
on the first new PC?

494
00:25:56.599 --> 00:25:59.040
4 meters, right?

495
00:25:59.040 --> 00:26:02.040
Then, the 5-year-old PC below

496
00:26:02.040 --> 00:26:03.280
can move twice

497
00:26:03.280 --> 00:26:05.040
Likewise, it can move 1 meter

498
00:26:05.040 --> 00:26:07.439
each time it moves

499
00:26:07.439 --> 00:26:12.479
Then it will move 2 meters in 1 second

500
00:26:12.479 --> 00:26:15.680
How about this?

501
00:26:15.680 --> 00:26:18.640
Since it's a new PC, it can move 4 meters in 1 second

502
00:26:18.640 --> 00:26:20.839
and this one can move 2 meters

503
00:26:20.839 --> 00:26:22.880
The PC above it can move fast

504
00:26:22.880 --> 00:26:25.959
when you play

505
00:26:25.959 --> 00:26:27.119
the game

506
00:26:27.119 --> 00:26:29.880
In other words, if a 5-year-old PC and a new PC play a game

507
00:26:29.880 --> 00:26:33.479
the first new PC will always win

508
00:26:33.479 --> 00:26:35.359
This is so unfair that

509
00:26:35.359 --> 00:26:38.119
users will stop playing the game

510
00:26:38.119 --> 00:26:42.770
Do you hear the sound of the low-priced users leaving?

511
00:26:42.770 --> 00:26:45.520
This is so unfair that

512
00:26:45.520 --> 00:26:47.880
the rules are so unfair

513
00:26:47.880 --> 00:26:50.560
So how can we make them arrive

514
00:26:50.560 --> 00:26:53.880
at the same location 1 second later?

515
00:26:53.880 --> 00:26:56.400
This is a very important point

516
00:26:56.400 --> 00:26:58.280
Then, instead of 4m or 2m

517
00:26:58.280 --> 00:27:02.640
how can we make them move at the same speed 1 second later

518
00:27:02.640 --> 00:27:04.880
and arrive at the same final destination?

519
00:27:04.880 --> 00:27:07.731
This is the core of deltaTime

520
00:27:09.810 --> 00:27:11.839
There is something called Delta in front of this

521
00:27:11.839 --> 00:27:15.160
This Delta is displacement and change

522
00:27:15.160 --> 00:27:16.920
This is displacement time

523
00:27:16.920 --> 00:27:19.079
What has changed? Time has changed

524
00:27:19.079 --> 00:27:20.199
How has it changed?

525
00:27:20.199 --> 00:27:24.119
Right here

526
00:27:24.119 --> 00:27:25.920
how long did it take from the first

527
00:27:25.920 --> 00:27:29.079
to the end of this frame?

528
00:27:29.079 --> 00:27:32.359
This is deltaTime

529
00:27:32.359 --> 00:27:35.079
If the whole thing is 1 second

530
00:27:35.079 --> 00:27:36.520
when you do it 4 times

531
00:27:36.520 --> 00:27:38.920
each frame, each space

532
00:27:38.920 --> 00:27:41.959
we call it a frame

533
00:27:41.959 --> 00:27:44.880
Did you play this game when you were young?

534
00:27:44.880 --> 00:27:47.280
There's a book like this

535
00:27:47.280 --> 00:27:50.683
If you have a book, you draw a picture here

536
00:27:50.683 --> 00:27:53.239
How about on the back?

537
00:27:53.239 --> 00:27:55.959
You draw a picture like this on the back

538
00:27:55.959 --> 00:27:57.880
A running picture

539
00:27:57.880 --> 00:28:00.239
and then we'll draw this on every page of the book

540
00:28:00.239 --> 00:28:04.319
and quickly flip through the book

541
00:28:04.319 --> 00:28:06.079
What if we flip through it quickly?

542
00:28:06.079 --> 00:28:09.280
We can create an animation

543
00:28:09.280 --> 00:28:10.119
that looks like it's running

544
00:28:10.119 --> 00:28:12.439
You've probably played this game before

545
00:28:12.439 --> 00:28:14.880
There's each of these

546
00:28:14.880 --> 00:28:16.640
What do we call each of these?

547
00:28:16.640 --> 00:28:18.560
It's a frame

548
00:28:18.560 --> 00:28:22.119
In some places, it's called a tick

549
00:28:22.119 --> 00:28:25.839
In Unity, each of these is called a frame

550
00:28:25.839 --> 00:28:29.439
Usually, in the animation or film industry

551
00:28:29.439 --> 00:28:31.719
for us to see these smoothly

552
00:28:31.719 --> 00:28:35.439
how many frames are created per second?

553
00:28:35.439 --> 00:28:37.439
These ones

554
00:28:37.439 --> 00:28:40.704
These are produced at about 24 frames per second

555
00:28:40.704 --> 00:28:43.839
That's why we call this frame rate per second

556
00:28:43.839 --> 00:28:47.941
or frames per second, fps

557
00:28:50.119 --> 00:28:52.445
This is not first-person shooting

558
00:28:52.445 --> 00:28:53.959
That's right, frame per second means

559
00:28:53.959 --> 00:28:57.199
24 frames are created per second

560
00:28:57.199 --> 00:29:00.119
These are usually in the animation field

561
00:29:00.119 --> 00:29:03.920
When you watch a movie in the theater, animated movies

562
00:29:03.920 --> 00:29:06.920
usually use about 24 frames

563
00:29:06.920 --> 00:29:08.220
Then, games

564
00:29:08.220 --> 00:29:12.520
usually use about 30 to 60 frames

565
00:29:12.520 --> 00:29:15.470
Content such as VR

566
00:29:15.470 --> 00:29:17.959
is available in at least 60 frames on mobile

567
00:29:17.959 --> 00:29:22.040
PCs use 90 frames or more

568
00:29:22.040 --> 00:29:25.000
Why? So that users don't feel dizzy

569
00:29:25.000 --> 00:29:27.119
when they turn their heads or eyes

570
00:29:27.119 --> 00:29:28.719
This frame rate per second

571
00:29:28.719 --> 00:29:32.119
fps is used

572
00:29:32.119 --> 00:29:37.359
Now, this deltaTime plays a very important role

573
00:29:37.359 --> 00:29:39.959
How short it takes

574
00:29:39.959 --> 00:29:44.512
will help determine the frame rate per second

575
00:29:44.512 --> 00:29:48.400
So, here's how deltaTime is used

576
00:29:48.400 --> 00:29:51.079
in the uniform motion formula

577
00:29:51.079 --> 00:29:54.520
If you look, this can move 1m

578
00:29:54.520 --> 00:30:00.881
However, the time taken for each section is 0.25 seconds

579
00:30:00.881 --> 00:30:04.131
so if you divide it by 1/4, it becomes 0.25 seconds

580
00:30:04.131 --> 00:30:08.750
So when we move, the distance

581
00:30:08.750 --> 00:30:12.100
is space S, just let's call it S

582
00:30:12.100 --> 00:30:16.059
Then, in terms of distance and time, let's call it deltaTime

583
00:30:16.059 --> 00:30:18.043
× D

584
00:30:20.679 --> 00:30:26.720
That's when we get this final location

585
00:30:26.720 --> 00:30:32.875
So, we have S × distance × time

586
00:30:32.875 --> 00:30:36.399
Let's see, when we do distance × time t, these two things?

587
00:30:36.399 --> 00:30:37.849
It moves 1m

588
00:30:37.849 --> 00:30:40.899
Let's multiply time by deltaTime

589
00:30:40.899 --> 00:30:43.959
What do we get? 0.25 seconds

590
00:30:43.959 --> 00:30:45.859
What is the value?

591
00:30:45.859 --> 00:30:50.009
The final distance traveled is 0.25 meters

592
00:30:50.009 --> 00:30:52.639
So, how many meters did it move when moving this section?

593
00:30:52.639 --> 00:30:54.239
0.25 meters

594
00:30:54.239 --> 00:30:57.839
After this, 0.25 m, 0.25 m, 0.25 m

595
00:30:57.839 --> 00:31:03.159
If we add them all up, the final distance it moved is 1 meter

596
00:31:03.159 --> 00:31:06.109
The same goes for the bottom, even though it's slow fit

597
00:31:06.109 --> 00:31:10.239
But it takes 0.5 seconds per section in deltaTime

598
00:31:10.239 --> 00:31:12.889
In this case, it took 0.5 seconds to move 1 meter

599
00:31:12.889 --> 00:31:17.760
If we multiply the two, how many meters did it move when moving this section?

600
00:31:17.760 --> 00:31:21.160
0.5 meters

601
00:31:21.160 --> 00:31:24.839
If we add the two, how many meters did it move? 1 meter

602
00:31:24.839 --> 00:31:28.289
So before, this one was 4 meters, and this one was 2 meters

603
00:31:28.289 --> 00:31:30.439
but now the two are the same

604
00:31:30.439 --> 00:31:34.320
So, deltaTime is used like this

605
00:31:34.320 --> 00:31:36.520
So, in the uniform motion formula

606
00:31:36.520 --> 00:31:40.640
P = P0 + vt

607
00:31:40.640 --> 00:31:44.234
but P = P0 + vt, the t at the end

608
00:31:44.234 --> 00:31:47.200
is the time of the movement

609
00:31:47.200 --> 00:31:51.307
Because of that time, we multiplied by deltaTime in the code

610
00:31:51.307 --> 00:31:54.320
but for synchronization processing

611
00:31:54.320 --> 00:31:57.920
you must multiply deltaTime

612
00:31:57.920 --> 00:32:01.239
This isn't just used for simple movement, right?

613
00:32:01.239 --> 00:32:04.839
Let's take a look at the form that you rotated

614
00:32:04.839 --> 00:32:06.289
Here's one character

615
00:32:06.289 --> 00:32:08.559
and here's two of them

616
00:32:08.559 --> 00:32:12.434
They're both looking this way

617
00:32:12.434 --> 00:32:14.760
Let's say there's a hammer here

618
00:32:14.760 --> 00:32:20.373
There's a hammer like this

619
00:32:20.373 --> 00:32:24.423
When they both say Start!, they'll spin around

620
00:32:24.423 --> 00:32:27.760
They'll spin around and hit this guy with the hammer

621
00:32:27.760 --> 00:32:31.260
This is the new PC, this is the old PC

622
00:32:31.260 --> 00:32:33.040
This guy can spin faster, right?

623
00:32:33.040 --> 00:32:37.190
Boom! What if he spins around, catches the hammer, and hits him?

624
00:32:37.190 --> 00:32:39.559
The new PC will win, right?

625
00:32:39.559 --> 00:32:41.859
That's why you have to multiply by

626
00:32:41.859 --> 00:32:45.359
deltaTime when processing the spin

627
00:32:45.359 --> 00:32:48.018
Okay, let's look at this case this time

628
00:32:50.640 --> 00:32:53.490
I'll put a pill here like this

629
00:32:53.490 --> 00:32:55.475
I'll put it like this

630
00:32:57.666 --> 00:33:05.003
When you say Start!, you can each take this pill

631
00:33:05.003 --> 00:33:07.716
you can each take it when you say Start!

632
00:33:07.716 --> 00:33:11.559
When you say Start!, this guy can take it, and this guy can take it

633
00:33:11.559 --> 00:33:15.600
At that time, this guy is the pill that expands

634
00:33:15.600 --> 00:33:19.920
This is the new PC, and this is the old PC

635
00:33:19.920 --> 00:33:22.570
This one will eat this and zoom in, how about that?

636
00:33:22.570 --> 00:33:24.187
It zooms in fast, right?

637
00:33:24.187 --> 00:33:27.037
4 times per second, and this one can zoom in twice

638
00:33:27.037 --> 00:33:28.559
so this one will zoom in four times

639
00:33:28.559 --> 00:33:30.709
So what does this one do? Boom

640
00:33:30.709 --> 00:33:35.599
So after it gets this big, I stomp on it and bang!

641
00:33:35.599 --> 00:33:38.239
This one's definitely going to win the game

642
00:33:38.239 --> 00:33:41.289
That is, when you rotate, what do you have to multiply by?

643
00:33:41.289 --> 00:33:43.280
You have to multiply by deltaTime

644
00:33:43.280 --> 00:33:46.030
When you try to change

645
00:33:46.030 --> 00:33:49.080
the position, rotation, and scale

646
00:33:49.080 --> 00:33:52.630
used in this transform component

647
00:33:52.630 --> 00:33:56.230
you have to multiply by deltaTime

648
00:33:56.230 --> 00:33:58.065
to synchronize them

649
00:34:01.842 --> 00:34:06.640
That's how we found out about deltaTime

650
00:34:06.640 --> 00:34:11.015
Next, let's change

651
00:34:11.015 --> 00:34:12.919
this transform.Translate

652
00:34:12.919 --> 00:34:15.019
to the uniform motion formula

653
00:34:15.019 --> 00:34:17.039
we just learned

654
00:34:17.039 --> 00:34:19.689
Instead of using the one provided by Unity

655
00:34:19.689 --> 00:34:22.689
let's implement dynamics by directly working on physics

656
00:34:22.689 --> 00:34:25.039
using the uniform motion formula

657
00:34:25.039 --> 00:34:26.205
What is the movement formula?

658
00:34:26.205 --> 00:34:30.960
It's P = P0 + vt

659
00:34:30.960 --> 00:34:33.460
So what we need first is P0

660
00:34:33.460 --> 00:34:36.522
P0 will be the current position of the player

661
00:34:40.287 --> 00:34:42.821
So, let's create P0 first

662
00:34:42.821 --> 00:34:47.871
Vector3, this is the data type in front

663
00:34:47.871 --> 00:34:50.471
It allows you to use the three elements

664
00:34:50.471 --> 00:34:53.512
provided by Unity: x, y, and z

665
00:34:53.512 --> 00:34:55.185
That's why it has the 3 at the end

666
00:34:55.187 --> 00:34:58.850
In 2D, it's Vector2

667
00:34:58.850 --> 00:35:01.750
When there's only one number? Just use float

668
00:35:01.750 --> 00:35:05.360
Since we're in 3D, let's put it like this: Vector3

669
00:35:05.360 --> 00:35:08.195
Let's put it as P0

670
00:35:08.195 --> 00:35:10.645
This is the current position of the player

671
00:35:10.645 --> 00:35:13.745
so there's a game object

672
00:35:13.745 --> 00:35:15.000
that PlayerMove is using

673
00:35:15.000 --> 00:35:18.000
Who has this player's position?

674
00:35:18.000 --> 00:35:19.116
Transform has it

675
00:35:19.116 --> 00:35:21.569
If we get this position value

676
00:35:21.569 --> 00:35:24.360
we can get its current position value

677
00:35:24.360 --> 00:35:26.236
How do we use it? Here's how you can write it

678
00:35:26.236 --> 00:35:28.686
transform.position

679
00:35:28.686 --> 00:35:33.279
If you write it like this, P0 is created right away

680
00:35:33.279 --> 00:35:37.779
This is putting my current position into P0

681
00:35:37.779 --> 00:35:40.729
Next, we need vt, right?

682
00:35:40.729 --> 00:35:45.383
So if we do vt to Vector3

683
00:35:45.383 --> 00:35:51.906
what happens to v? This much will be v

684
00:35:51.906 --> 00:35:53.424
This much is v

685
00:35:55.639 --> 00:35:58.489
The thing after this is direction, and this is magnitude

686
00:35:58.489 --> 00:36:01.739
so this much in magnitude × direction is v

687
00:36:01.739 --> 00:36:03.919
Next, t is deltaTime

688
00:36:03.919 --> 00:36:10.279
So if we multiply this by the end, this becomes vt

689
00:36:10.279 --> 00:36:14.026
Then, let's create the last P = P0 + vt

690
00:36:14.026 --> 00:36:20.000
P = P0 + vt

691
00:36:20.000 --> 00:36:22.900
It will be like this, then it will finally be created according to this formula

692
00:36:22.900 --> 00:36:25.700
Since we got the value like this

693
00:36:25.700 --> 00:36:28.919
it should be updated to my final current position

694
00:36:28.919 --> 00:36:32.269
So transform.position

695
00:36:32.269 --> 00:36:33.419
What do I put

696
00:36:33.419 --> 00:36:35.619
in my current position? If I put P

697
00:36:35.619 --> 00:36:37.760
​​this value will be updated

698
00:36:37.760 --> 00:36:42.720
This part is no longer needed so that you can delete it

699
00:36:42.720 --> 00:36:48.670
We create this using the uniform motion formula

700
00:36:48.670 --> 00:36:51.599
that changes the current player's position

701
00:36:51.599 --> 00:36:53.787
Let's see if it has changed the same

702
00:36:56.228 --> 00:37:00.117
If you press the play button, the user will continue to move to the right

703
00:37:02.000 --> 00:37:03.064
It looks like this

704
00:37:03.064 --> 00:37:06.811
Implementing Movement Based on User Input

705
00:37:07.336 --> 00:37:10.436
Then, this time, let's implement movement

706
00:37:10.436 --> 00:37:11.687
based on user input

707
00:37:14.857 --> 00:37:18.357
User input creates this that can get

708
00:37:18.357 --> 00:37:21.775
the direction based on the user's input

709
00:37:21.775 --> 00:37:23.625
It allows you to get the user's direction

710
00:37:23.625 --> 00:37:25.325
What is the direction here?

711
00:37:25.325 --> 00:37:28.160
This part will be the user's direction

712
00:37:28.160 --> 00:37:29.810
In particular, since this is the size

713
00:37:29.810 --> 00:37:32.759
this part can be limited to the direction

714
00:37:32.759 --> 00:37:35.736
Here, the parts that we need to learn a little more about

715
00:37:38.119 --> 00:37:39.969
Vector3.right are

716
00:37:39.969 --> 00:37:42.319
that this Vector3 part

717
00:37:42.319 --> 00:37:46.769
creates a direction

718
00:37:46.769 --> 00:37:49.440
with three components: x, y, and z

719
00:37:49.440 --> 00:37:53.383
In Unity, x means right

720
00:37:53.383 --> 00:38:00.000
y means up, and z means directly in front

721
00:38:00.000 --> 00:38:01.313
In English

722
00:38:03.559 --> 00:38:07.009
this x direction can be called right

723
00:38:07.009 --> 00:38:08.737
this can be called up

724
00:38:08.737 --> 00:38:10.156
and this can be called forward

725
00:38:11.720 --> 00:38:15.180
When it becomes like this

726
00:38:16.647 --> 00:38:20.597
How does each value go into x, y, and z?

727
00:38:20.597 --> 00:38:23.279
Vector3.right needs to enter the values ​​of these three components

728
00:38:23.279 --> 00:38:27.179
In other words, since x is right, the value goes into this as 1

729
00:38:27.179 --> 00:38:30.360
y goes into 0, and z also goes into 0

730
00:38:30.360 --> 00:38:34.110
Since it will go to the right if there is no value

731
00:38:34.110 --> 00:38:35.800
Its size is 1

732
00:38:35.800 --> 00:38:37.900
Here's how to find the magnitude

733
00:38:37.900 --> 00:38:44.039
You can find it like this, √(x^2 + y^2 + z^2)

734
00:38:44.039 --> 00:38:47.379
Since this is 1, the remainder is 0, and the square root of 1 is 1

735
00:38:47.379 --> 00:38:49.594
So, the magnitude becomes 1

736
00:38:52.479 --> 00:38:54.629
It becomes like this

737
00:38:54.629 --> 00:38:58.240
Then, in addition to the right, there will also be up

738
00:38:58.240 --> 00:39:00.190
What will up be like?

739
00:39:00.190 --> 00:39:03.921
In this form, you only need to enter a value for the y-axis

740
00:39:03.921 --> 00:39:07.821
That is, x is 0, and y is 1

741
00:39:07.821 --> 00:39:09.471
When is it going forward?

742
00:39:09.471 --> 00:39:13.160
It'll be 0 for y and 1 for z

743
00:39:13.160 --> 00:39:16.399
What do you multiply when the direction changes?

744
00:39:16.399 --> 00:39:21.519
I said that if you multiply by -1, the vector will flip

745
00:39:21.519 --> 00:39:25.019
So if you say you're going backward

746
00:39:25.019 --> 00:39:27.720
If you want to go backwards in a vector, this is in front

747
00:39:27.720 --> 00:39:30.440
You can multiply by -1

748
00:39:30.440 --> 00:39:34.690
On the left, multiply x by -1

749
00:39:34.690 --> 00:39:37.239
That means multiply by × -1

750
00:39:37.239 --> 00:39:41.039
Since each component is multiplied like this

751
00:39:41.039 --> 00:39:44.000
0 × -1 is 0

752
00:39:44.000 --> 00:39:50.440
So, you can also do this to go down

753
00:39:50.440 --> 00:39:53.290
So, if you × -1, the vector is flipped

754
00:39:53.290 --> 00:39:54.910
You just need to know this

755
00:39:56.920 --> 00:39:59.220
Then, let's implement the content

756
00:39:59.220 --> 00:40:02.170
that receives user input and makes the player

757
00:40:02.170 --> 00:40:04.040
move up, down, left, and right

758
00:40:04.040 --> 00:40:08.090
Then, let's first get the user's input

759
00:40:08.090 --> 00:40:10.467
to create a direction here

760
00:40:15.299 --> 00:40:22.094
We want to create a direction by getting the user's input

761
00:40:25.119 --> 00:40:27.119
Then, how do we get the user's input?

762
00:40:27.119 --> 00:40:31.239
We use a class called Input to get the user's input

763
00:40:31.239 --> 00:40:34.962
Then, picture class 1 in your head

764
00:40:34.962 --> 00:40:36.600
Then, what happens?

765
00:40:36.600 --> 00:40:38.700
We go into the function as an attribute

766
00:40:38.700 --> 00:40:41.150
We'll go into the function here

767
00:40:41.150 --> 00:40:44.640
We'll go into the GetAxis function

768
00:40:44.640 --> 00:40:46.640
GetAxis can get the inputs

769
00:40:46.640 --> 00:40:49.079
that the user is continuously pressing

770
00:40:49.079 --> 00:40:51.579
Here, we'll get the Horizontal input

771
00:40:51.579 --> 00:40:56.304
which is the left and right input

772
00:40:57.880 --> 00:41:01.912
If the user doesn't press any key

773
00:41:01.912 --> 00:41:04.760
GetAxis returns a value of 0

774
00:41:04.760 --> 00:41:10.410
However, if the user presses the A key or the left arrow key

775
00:41:10.410 --> 00:41:13.079
it returns a value of -1

776
00:41:13.079 --> 00:41:18.429
It gradually changes from 0 to -0.1, -0.2

777
00:41:18.429 --> 00:41:21.479
and returns a value up to -1

778
00:41:21.479 --> 00:41:25.079
If the right key is pressed, it returns a value of +1

779
00:41:25.079 --> 00:41:26.129
We'll use this

780
00:41:26.129 --> 00:41:29.200
to create the direction of this vector

781
00:41:29.200 --> 00:41:33.750
We'll store this as a value for the Horizontal input

782
00:41:33.750 --> 00:41:38.054
for the left and right input, which is a container called float h

783
00:41:38.054 --> 00:41:40.679
So, where is this Horizontal value?

784
00:41:40.679 --> 00:41:47.129
If you go to Unity and scroll down to the Edit menu

785
00:41:47.129 --> 00:41:49.961
you will find Project Settings

786
00:41:49.961 --> 00:41:54.959
If you go in there, you'll see Input Manager

787
00:41:54.959 --> 00:41:57.566
There's a section called Axes in the Input Manager

788
00:41:57.566 --> 00:42:01.665
If you open that, you'll see Horizontal

789
00:42:01.665 --> 00:42:03.715
If you look under that, you'll see Vertical, Fire1

790
00:42:03.715 --> 00:42:08.959
that Unity has mapped

791
00:42:08.959 --> 00:42:10.839
inputs to in advance

792
00:42:10.839 --> 00:42:13.920
If you open Horizontal, the name is Horizontal

793
00:42:13.920 --> 00:42:19.799
and here it says Negative Button, left

794
00:42:19.799 --> 00:42:23.040
Next, Positive Button is right

795
00:42:23.040 --> 00:42:26.279
That means the left and right arrow keys

796
00:42:26.279 --> 00:42:28.239
It means negative and positive numbers

797
00:42:28.239 --> 00:42:33.289
the Alt key and other alternative Negative buttons

798
00:42:33.289 --> 00:42:34.720
are the a and d keys

799
00:42:34.720 --> 00:42:38.170
So when you press the left, right, a, and d keys

800
00:42:38.170 --> 00:42:40.480
Horizontal responds

801
00:42:40.480 --> 00:42:44.679
This value passes a value between -1 and 1

802
00:42:44.679 --> 00:42:46.322
It's defined here

803
00:42:46.322 --> 00:42:48.440
It's defined like this

804
00:42:48.440 --> 00:42:51.090
Vertical is up, down

805
00:42:51.090 --> 00:42:53.119
and s, w

806
00:42:53.119 --> 00:42:55.160
What's in fire1?

807
00:42:55.160 --> 00:42:58.310
Left ctrl key or left mouse button

808
00:42:58.310 --> 00:43:00.239
0 is the left mouse button

809
00:43:00.239 --> 00:43:03.239
The values ​​are defined like this

810
00:43:03.239 --> 00:43:05.589
We put the values ​​defined here

811
00:43:05.589 --> 00:43:07.572
and work with them

812
00:43:07.572 --> 00:43:13.279
We will process the values ​​using these values

813
00:43:13.279 --> 00:43:15.799
Then, let's first change

814
00:43:15.799 --> 00:43:20.000
the direction to the value we put here instead of this

815
00:43:20.000 --> 00:43:26.640
So we're going to put dir in Vector3

816
00:43:26.640 --> 00:43:31.119
This is right

817
00:43:31.119 --> 00:43:32.520
It's the right value

818
00:43:32.520 --> 00:43:37.343
If we do this, this dir has right in it

819
00:43:37.343 --> 00:43:40.799
and if we just do this instead of right, what happens?

820
00:43:40.799 --> 00:43:43.919
It moves to the right, and the same value will appear

821
00:43:43.919 --> 00:43:46.919
At that time, if we want to

822
00:43:46.919 --> 00:43:49.440
apply the user's input value to this

823
00:43:49.440 --> 00:43:54.039
we multiply it by the scalar value h

824
00:43:54.039 --> 00:43:56.479
Then what happens internally?

825
00:43:56.479 --> 00:44:00.719
Right is 1, 0, 0

826
00:44:00.719 --> 00:44:03.280
and if h is -1 here

827
00:44:03.280 --> 00:44:05.599
if we press the left key and do this

828
00:44:05.599 --> 00:44:08.119
each component will be multiplied like this

829
00:44:08.119 --> 00:44:09.559
Then what happens?

830
00:44:09.559 --> 00:44:12.200
It will be -1, 0, 0, so it will be the left

831
00:44:12.200 --> 00:44:15.760
If we press the right, it will be +1, so it will just be 1, 0, 0

832
00:44:15.760 --> 00:44:17.080
and it will go to the right

833
00:44:17.080 --> 00:44:19.760
If we don't press anything, this has a value of 0

834
00:44:19.760 --> 00:44:23.919
So the direction will be 0, so nothing will move

835
00:44:23.919 --> 00:44:27.320
0 × 5 is all 0, right?

836
00:44:27.320 --> 00:44:30.520
So, if we multiply this by h here

837
00:44:30.520 --> 00:44:33.080
we can immediately set the direction

838
00:44:33.080 --> 00:44:36.280
Let's play this

839
00:44:36.280 --> 00:44:39.280
Play

840
00:44:39.280 --> 00:44:41.640
Let's press the left and right keys on the keyboard

841
00:44:41.640 --> 00:44:44.340
Then you can see that the character, the player

842
00:44:44.340 --> 00:44:47.320
moves left and right like this

843
00:44:47.320 --> 00:44:50.960
Okay? Then how about the up and down input?

844
00:44:50.960 --> 00:44:54.080
As I mentioned earlier

845
00:44:54.080 --> 00:44:56.919
what was this value in the Input Manager?

846
00:44:56.919 --> 00:44:59.719
It was Vertical
Let's create another one

847
00:44:59.719 --> 00:45:04.320
Let's call it v, and this time, put it as Vertical

848
00:45:04.320 --> 00:45:07.559
You have to distinguish between upper and lower case letters

849
00:45:07.559 --> 00:45:10.719
Then the user's input is like this

850
00:45:10.719 --> 00:45:12.919
If I want to add one more Vertical

851
00:45:12.919 --> 00:45:15.599
do I have to create another direction to move it?

852
00:45:15.599 --> 00:45:16.719
You don't have to do that

853
00:45:16.719 --> 00:45:19.640
You can use vector addition

854
00:45:19.640 --> 00:45:23.590
How? What happens if you add

855
00:45:23.590 --> 00:45:27.440
these two vectors, one going to the right and one going up?

856
00:45:27.440 --> 00:45:30.039
I said you can put this here

857
00:45:30.039 --> 00:45:34.551
That's how this vector is created, right?

858
00:45:34.551 --> 00:45:37.440
So you can add the two vectors

859
00:45:37.440 --> 00:45:45.080
+ Vector3.up * v, if you do this

860
00:45:45.080 --> 00:45:50.359
when the value is -1, it will go down, and the vector

861
00:45:50.359 --> 00:45:52.309
This is 0, 1, 0

862
00:45:52.309 --> 00:45:55.799
so when it's +1, it will just go up

863
00:45:55.799 --> 00:45:58.999
Then, if you change this formula

864
00:45:58.999 --> 00:46:00.599
for moving an object

865
00:46:00.599 --> 00:46:02.743
you can make it like this

866
00:46:11.280 --> 00:46:16.472
It's about finding directions

867
00:46:16.472 --> 00:46:17.919
Up to here, it's about finding directions

868
00:46:17.919 --> 00:46:20.892
What's the content below?

869
00:46:20.892 --> 00:46:22.242
It's about moving

870
00:46:22.242 --> 00:46:27.840
You can use sentences like this to distinguish them

871
00:46:27.840 --> 00:46:29.540
Then, moving

872
00:46:29.540 --> 00:46:32.159
always ends with the word moving

873
00:46:32.159 --> 00:46:34.609
If you want to change the direction or do various tasks

874
00:46:34.609 --> 00:46:37.159
you can just change the code here

875
00:46:37.159 --> 00:46:38.759
Even if you create a function

876
00:46:38.759 --> 00:46:44.080
you can just change and create this part of the function

877
00:46:44.080 --> 00:46:47.400
I've done it to move the user up, down, left, and right like this

878
00:46:47.400 --> 00:46:49.814
Let's test it, play

879
00:46:51.919 --> 00:46:56.869
Then, you can see that it moves when the user presses

880
00:46:56.869 --> 00:46:59.393
the left, right, up, down, left, and right keys

881
00:47:02.520 --> 00:47:05.320
Then, we'll continue to look at

882
00:47:05.320 --> 00:47:07.760
this part in more detail

883
00:47:07.760 --> 00:47:12.239
How can we see the light of a vector?

884
00:47:12.239 --> 00:47:15.789
You can see the light of a vector like this

885
00:47:15.789 --> 00:47:17.760
(1, 0, 0)

886
00:47:17.760 --> 00:47:20.746
What happens if you multiply it by h?

887
00:47:20.746 --> 00:47:23.880
(h, 0, 0)

888
00:47:23.880 --> 00:47:25.530
Let's add them

889
00:47:25.530 --> 00:47:27.880
The up × v of a vector can be seen like this

890
00:47:27.880 --> 00:47:31.359
(0, v, 0), let's add two of them

891
00:47:31.359 --> 00:47:36.000
Then, what will the final value be? (h, v, 0)

892
00:47:36.000 --> 00:47:39.900
In other words, can we put each component

893
00:47:39.900 --> 00:47:43.612
in x, y, and z like this?

894
00:47:43.612 --> 00:47:47.359
So we can modify our code like this

895
00:47:47.359 --> 00:47:48.687
If you place the part like this

896
00:47:50.960 --> 00:47:56.085
in the new Vector3 as (h, v, 0)

897
00:47:56.085 --> 00:48:00.960
the content will be the same

898
00:48:00.960 --> 00:48:04.035
Let's save and play again

899
00:48:06.599 --> 00:48:10.960
It can be implemented similarly when moving up, down, left, and right

900
00:48:10.960 --> 00:48:15.280
So, we add to the vector and extract the final result

901
00:48:15.280 --> 00:48:18.380
Those results can be entered into the vector like this

902
00:48:18.380 --> 00:48:20.320
and the content can be the same

903
00:48:20.320 --> 00:48:22.370
So, does that mean we don't need to add to the vector?

904
00:48:22.370 --> 00:48:24.080
You might say that

905
00:48:24.080 --> 00:48:26.346
No, adding to the vector is

906
00:48:26.346 --> 00:48:29.440
necessary because it implements the sum of all forces

907
00:48:29.440 --> 00:48:32.840
I'll show you that this can be used

908
00:48:32.840 --> 00:48:35.320
when you reduce the user's input to a single value

909
00:48:35.320 --> 00:48:37.320
The code may appear like this

910
00:48:37.320 --> 00:48:39.870
when you study and search

911
00:48:39.870 --> 00:48:43.239
on YouTube or Google

912
00:48:43.239 --> 00:48:47.289
Ultimately, these are based on adding to a vector

913
00:48:47.289 --> 00:48:49.792
I hope you understand this

914
00:48:51.049 --> 00:48:54.280
Let's summarize what we learned in this section

915
00:48:54.280 --> 00:48:57.239
First, we learned about vectors

916
00:48:57.239 --> 00:49:00.239
Vectors consist of magnitude and direction

917
00:49:00.239 --> 00:49:04.919
and can perform addition, subtraction, inner product, and outer product operations

918
00:49:04.919 --> 00:49:08.840
Second, we learned about the uniform motion formula

919
00:49:08.840 --> 00:49:11.190
We learned about the uniform motion formula for moving an object

920
00:49:11.190 --> 00:49:14.039
P = P0 + vt

921
00:49:14.039 --> 00:49:17.280
We created the player's movement

922
00:49:17.280 --> 00:49:20.919
We moved the player based on the uniform motion formula

923
00:49:20.919 --> 00:49:25.359
We also learned about the meaning and use of deltaTime

924
00:49:25.359 --> 00:49:29.080
We implemented movement according to user input

925
00:49:29.080 --> 00:49:32.116
We used the inf class to get the user's input

926
00:49:32.116 --> 00:49:35.216
and applied the player's movement by calculating the up, down, left, right directions

927
00:49:35.216 --> 00:49:37.137
based on the user's input

928
00:49:37.581 --> 00:49:41.031
Understanding Vectors
Vector
Vectors have magnitude and direction
Can be added, subtracted, and multiplied (inner product, outer product)
The sum of all forces can be expressed by adding vectors

929
00:49:41.031 --> 00:49:44.472
Direction=B-A (a formula to find the direction in which A wants to go to B)

930
00:49:44.472 --> 00:49:47.972
Understanding the Uniform Motion Formula and Creating Player Movement
Uniform Motion
Use the formulas for movement, velocity, and force as the physical laws for moving objects
P=P0+vt / v=v0+at / F=ma

931
00:49:47.972 --> 00:49:51.481
DeltaTime
The time between the previous frame and the current frame
It is important to match the distance traveled per second regardless of the PC specifications

932
00:49:51.481 --> 00:49:52.723
Implementing movement based on user input
User input processing
Write code to respond to the input of the left and right keys, A, and D keys on the keyboard

933
00:49:52.723 --> 00:49:53.985
Write code to respond to the input of up, down, left, and right using Horizontal and Vertical registered in the properties of [Edit - Project Settings - Input Manager]

934
00:49:53.985 --> 00:49:55.188
Creating a direction
Implementing the content of 'Creating a direction and moving according to user input'

935
00:49:55.188 --> 00:49:56.386
Using the value received from user input to create a direction
(Vector3 dir=Vector3.right*h+Vector3.up*v)

936
00:49:56.386 --> 00:49:57.371
Using (h, 0, 0)+(0, v, 0)=(h, v, 0), change the script to new Vector3(h, v, 0)