2 - Basic Gameplay

Question 1

2.2.1 - Make the projectile fly forwards

Write the code to make a projectile prefab move forward through the scene. Utilize the variable ‘speed’ as though it has been defined in the script.

Answer 1

transform.Translate(Vector3.forward * time.Deltatime * speed)

Question 2

2.2.1 - Make the projectile fly forwards

What would happen if the code used to make a projectile prefab move through the scene only consisted of transform.Translate(Vector3.forward * time.Deltatime) - missing a speed variable

Answer 2

The code will still compile and execute, however the object would likely move imperceptibly slow. This is because without a speed variable it’s just being scaled by time.Deltatime, which is .16 seconds per frame(@ 60fps)

Question 3

2.2.1 - Make the projectile fly forwards

What would happen if the code used to make a projectile prefab move through the scene only consisted of transform.Translate(Vector3.forward) - missing a speed variable and time.Deltatime

Answer 3

Vector3.forward is shorthand for (0,0,1), so without deltatime or a speed variable it would move the object forward 1 unit per second * fps along the z axis.

Question 4

2.2.1 - Make the projectile fly forwards

Define the code for a variable we will use as speed for our projectile prefab. Value is your preference.

Answer 4

public float speed = 10.0f

Question 5

2.2.1 - Make the projectile fly forwards

What is a Prefab?

Answer 5

An asset we can keep re-using anytime, anywhere and it will always have the same behavior

Question 6

2.2.2 - Make the projectile into a prefab

What happens when you drag an object to your Prefab folder?

Answer 6

Unity will ask if you want to create new or create variant

Question 7

2.2.2 - Make the projectile into a prefab

We want the projectile to spawn from the player itself, meaning the playerobject must have a reference to the prefab projectile. What is the reference we need to write in the PlayerController script?

Answer 7

public GameObject projectilePrefab

Gameobject is a unity class, projectilePrefab is the name we are giving the variable that will be viewable in the Inspector.

Question 8

2.2.2 - Make the projectile into a prefab

We want the projectile to spawn from the player itself. We’ve written the public GameObject projectilePrefab reference into the PlayerController script. What should you do with the projectile prefab object now?

Answer 8

You want to drag the projectilePrefab from the folder to the component in the Inspector, on your PlayerObject.

Question 9

2.2.3 - Test for spacebar press

We need to write code to press a button that launches the projectile. What script should you write the code in, in what section of script should it be written, and what type of statement do you use?

Answer 9

Since it will spawn from the PlayerContoller, you want to use that gameObjects script to write the code.

The code type you will use is an ‘if’ statement (IF button is pressed, then LAUNCH projectile)

Should be written in the Update section, as this updates every frame.

if( )
{

}

Question 10

2.2.3 - Test for spacebar press

Write the code in the PlayerController script to launch projectile when the space bar is pressed down.

Answer 10

if (Input.GetKeydown(KeyCode.Space));

Question 11

2.2.3 - Test for spacebar press

What does GetKey do?

Answer 11

GetKey makes Unity’s Input class check whether a specific key on the keyboard is being held down during the current frame.

Question 12

2.2.3 - Test for spacebar press

What is the difference between GetKeyDown and GetKeyUp?

Answer 12

GetKeyDown checks for the frame the key is first pressed. GetKeyUp checks for the frame the key is released.

Question 13

2.2.3 - Test for spacebar press

What does KeyCode do?

Answer 13

Provides a set of constants that are mapped to all the keys. Makes it easy for you to locate the key you want to use.

Question 14

2.2.3 - Test for spacebar press

What is happening in this code?
if (Input.GetKeydown(KeyCode.Space));

Answer 14

The code checks if the Spacebar key was pressed down during the current frame.

Question 15

2.2.4 - Launch projectile on spacebar press

You’ve written the if statement for Unity to check when there is a space bar press.
if(Input.GetKeyDown(KeyCode.Space)

Now, write the string within the brackets { } to launch the projectile when the space bar is pressed.

HINT: Remember that we want the projectile to spawn FROM the playerObject.

Answer 15

{
Instantiate(projectilePrefab, transform.position, projectilePrefab.transform.rotation);
}

Question 16

2.2.4 - Launch projectile on spacebar press

What is Instantiate?

Answer 16

it’s another way of saying we are going to create an object, or in this case create copies of an object that already exists.

Question 17

2.2.4 - Launch projetile on spacebar press

What is the code syntax for Instantiate?

Answer 17

Instantiate(Object original, Vector3 position, Quaternion rotation)

Question 18

2.2.4 - Launch projectile on spacebar press

The generic code string for our if statement to launch the projectile is:
Instantiate(Object original, Vector3 position, Quaternion rotation)

Define what each part of the code is doing.

Answer 18

Instantiate - Creating copies of our object
Object original - this is the prefab we are instantiating (projectilePrefab in this example)
Vector3 position - The position at which we want our object to start at.
Quaternion rotation - It’s asking for the rotation is should be.

Question 19

2.2.4 - Launch projectile on spacebar press

Our if statement code to launch the projectile is the following:

Instantiate(projectilePrefab, transform.position, projectilePrefab.transform.rotation);

Explain what each part corresponds to and why we are doing it.

Answer 19

1.Instantiate will create copies of our prefab
2.projectilePrefab is our Object original, and it is the prefab we will be creating copies of in Instantiation.
3. transform.position is the Vector3 position we want the object to start at. Because we are spawning the projectile on the playerObject, we are using transform.position.
4. This is the Quaternion rotation which is Unity asking what the rotation should be. Rotation is already set up in the prefab, and stored in it’s transform. So we reference the prefab, and then write transform.rotation.

Question 20

2.2.5 - Make animals into prefabs

What do you need to do with the animal prefabs in order to get them to move forward, toward the player character?

Answer 20

Attach the same MoveForward script that the projectilePrefab uses to move to each of the animals. Preferably before moving it to the prefab folder.

Question 21

2.2.6 - Destroy projectiles offscreen

Write code to destroy the projectile if it goes out of bounds on the Z axis

HINT: variable topBound

Answer 21

if(transform.position.z > topBound)
{
Destroy(gameObject);
}

Question 22

2.2.6 - Destroy projectiles offscreen

Write a new variable to define topBound with a value of 30.

Answer 22

private float topBound = 30.0f

Question 23

2.2.7 - destroy animals offscreen

Write a new variable lowerBound so we can destroy animals past a certain Z value

HINT: negative value

Answer 23

private float lowerBound = -10.0f

Question 24

2.2.7 - destroy animals offscreen

In the if statement that describes what happens if a gameobject hits your topBound, write the ‘else’ statement for animals that hit your lowerBound.

Answer 24

else if (transform.position.z < lowerBound)
{
Destroy(gameObject);
}

Question 25

# 2.2.6 - Destroy projectiles offscreen 2.2.6 - If you're adding a new script to an existing prefab, what do you need to do to make sure the prefab has been updated to run the new script

Answer 25

Select Overrides in the Inspector and select Apply

Question 26

# 2.2.7 - destroy animals offscreen What is an 'else if' statement?

Answer 26

Something you add on to the end of an if statement so you can fulfill unique situations.

Question 27

# 2.3.1- Create a Spawn Manager What is an Array?

Answer 27

An Array in programming is something that you can use to store multiple objects or variables inside of

Question 28

# 2.3.1 - Create a Spawn Manager What does [] mean?

Answer 28

An array

Question 29

# 2.3.1 - Create a Spawn Manager We need to create an array for animal prefabs. Write the variable to store the array using the title "animalPrefabs".

Answer 29

public GameObject [] animalPrefabs;

Question 30

# 2.3.1 - Create a Spawn Manager Why would we create an empty game object to attach our SpawnManager script to?

Answer 30

So that we can create the public variable array for use in the Inspector and to assign our animal prefabs as elements.

Question 31

# 2.3.2 - Spawn an animal if S is pressed Write the If statement in the SpawnManager script for when the 'S' key is pressed.

Answer 31

if(Input.GetKeyDown(KeyCode.S));

Question 32

# 2.3.2 - Spawn an animal if S is pressed Write the code to Instantiate the animalPrefabs array. Use 0 for the Array number, and set the spawn position to z = 20.

Answer 32

Instantiate(animalPrefabs[0], new Vector3(0,0,20), animalPrefabs[0].transform.rotation);

Question 33

# 2.3.2 - Spawn an animal if S is pressed In the animalPrefabs game object in the Inspector, how do you choose how many elements to use?

Answer 33

Set the number at the right in the component to the number of elements you wish to utilize, and the element boxes will fill to that number.

Question 34

# 2.3.2 - Spawn an animal if S is pressed When you've created a public array, you can assign prefabs to an Element in the Inspector. Each element is given a number. What is the term for these numbers? (e.g. Element 0, Element 1)

Answer 34

Index numbers

Question 35

# 2.3.2 - Spawn an animal if S is pressed The code below will spawn Element 0 when the 'S' key is pressed. '0' is an Index Number in our array 'animalIndex' What do we need to change in the code to be able to spawn any object from the array? Instantiate(animalPrefabs[0], new Vector3(0,0,20), animalPrefabs[0].transform.rotation);

Answer 35

The index number needs to be changed to instead reference the name of the array. Instantiate(animalPrefabs[**animalindex**], new Vector3(0,0,20), animalPrefabs[**animalIndex**].transform.rotation);

Question 36

# 2.3.3 - Spawn random animals from array We want to have the program randomly select the animals to spawn and not have us telling it what to spawn. What method do we need to use to accomplish this?

Answer 36

Random

Question 37

# 2.3.3 - Spawn random animals from array If you have a variable you'll use throughout your code, where should you put it?

Answer 37

Put it outside of any methods (at the top)

Question 38

# 2.3.3 - Spawn random animals from array What happens if we move a variable into a method?

Answer 38

It will only be seen within that method

Question 39

# 2.3.3 - Spawn random animals from array What happens if we try to call a variable in the start method that we defined in the update method.

Answer 39

Unity will not recognize the variable and will not be able to call it.

Question 40

# 2.3.3 - Spawn random animals from array What does the Random method do?

Answer 40

Used to generate random numbers

Question 41

# 2.3.3 - Spawn random animals from array What is the Range method?

Answer 41

Will pull a number between the first and last numbers we select

Question 42

# 2.3.3 - Spawn random animals from array If our elements we are using are labeled 0 -2 in range, then what numbers should we use for our Range? Why?

Answer 42

(0,3) The last number will not actually be counted. The last number is called an exclusive number meaning it won't be used.

Question 43

# 2.3.3 - Spawn random animals from array In reference to an array, what does Length refer to?

Answer 43

Refers to the number of elements in the array or collection.

Question 44

# 2.3.4 - Randomize the spawn location We want to spawn the animal within a random X range. In your Instantiate code, what part of the string would you modify, and what would you replace it with?

Answer 44

You would modify the Vector3 object position. Vector3 format is (x, y, z), so we modify the first position to modify the X values. We would replace the number here with Random.Range(x, x).

Question 45

# 2.3.4 - Randomize the spawn location Write the code to Instantiate animal spawns with a random X-axis range, and set the Z axis to 20. Use the GameObject 'animalPrefabs' with index 'animalIndex'.

Answer 45

Instantiate(animalPrefabs[animalindex], new Vector3(Random.Range(-20,20, 0 ,20), animalPrefabs[animalIndex].transform.rotation);

Question 46

# 2.3.4 - Randomize the spawn location Lets clean up our Instantiate code by writing a variable for our random spawn. Remove the Vector3 code from your Instantiate code and turn it into a variable called 'spawnPos'. Use Random.Range for your X with -20, 20, and make Z axis 20.

Answer 46

Vector3 spawnPos = new Vector3(Random.Range(-20, 20), 0, 20);

Question 47

# 2.3.4 - Randomize the spawn location Remove the spawn position from your Instantiate code and turn it into a variable called spawnPos. Use SpawnRangeX for your X value, and spawnPosZ for your Z.

Answer 47

Vector3 spawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), 0, spawnPosZ);

Question 48

# 2.3.4 - Randomize the spawn location ** We've pulled the Vector3 position out of our instantiate code and created a varible: Vector3 spawnPos = new Vector3(Random.Range(-20, 20), 0, 20); Rewrite the Instantiate code to account for the variable. Use the GameObject 'animalPrefabs' with index 'animalIndex.

Answer 48

Instantiate(animalPrefabs[animalIndex], spawnPos, animalPrefabs[animalIndex].transform.rotation;

Question 49

# 2.3.5 - Change the perspective of the camera **** Where do you go to change the perspective of your camera?

Answer 49

In the Camera object, In the inspector, go to the Perspective dropdown and select Perspective or Orthographic.

Question 50

# 2.3.5 - Change the perspective of the camera What is Perspective view?

Answer 50

Objects appear smaller as they are farther from the camera, mimicking human vision and creating depth

Question 51

# 2.3.5 - Change the perspective of the camera What is Orthographic view?

Answer 51

Objects stay the same size regardless of distance from the camera, removing depth and creating a flat, 2D-like view.

Question 52

# 2.4.1 - Make a new method to Spawn animals What is void?

Answer 52

void is a return type that performs an action

Question 53

# 2.4.1 - Make a new method to Spawn animals What is a method?

Answer 53

1. A block of code that performs a specific task 2. Can be called by its name.

Question 54

# 2.4.1 - Make a new method to Spawn animals Why would we create our own, custom functions?

Answer 54

1. Makes it easier to read and manage 2. makes sure certain tasks you need for a specific purpose are only kept inside a specific method 3. can reuse as much as needed.

Question 55

# 2.4.1 - Make a new method to Spawn animals We have the following code in the Update method: void Update() { if(Input.GetKeyDown(KeyCode.S)) int animalIndex = Random.Range(0, animalPrefabs.Length); Vector3 spawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), 0, spawnPosZ); Instantiate(animalPrefabs[animalIndex], spawnPos, animalPrefabs[animalIndex].transform.rotation; } 1. Move the necessary code out of the Update method and create a new custom function for it. Name the new function SpawnRandomAnimal. 2. In the Update method, with the code for spawning removed, what needs to be added for when the S key is pressed?

Answer 55

void Update() { if (Input.GetKeyDown(KeyCode.S)) SpawnRandomAnimal(); void SpawnRandom Animal() { int animalIndex = Random.Range(0, animalPrefabs.Length); Vector3 spawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), 0, spawnPosZ); Instantiate(animalPrefabs[animalIndex], spawnPos, animalPrefabs[animalIndex].transform.rotation; }

Question 56

# 2.4.2 - Spawn the Animals at timed intervals What is InvokeRepeating?

Answer 56

Calls a specified method repeatedly at a set time interval.

Question 57

# 2.4.2 - Spawn the Animals at timed intervals What is the code syntax used to write InvokeRepeating?

Answer 57

InvokeRepeating("MethodName", time, repeatRate);

Question 58

# 2.4.2 - Spawn the Animals at timed intervals 1. Write an InvokeRepeating statement, and write the variables needed outside the method. You may name the method and variables whatever you wish. The start delay time is 1 second, the interval time is 2 seconds. 2. Write the syntax of the statement

Answer 58

private float startDelay = 1; private float spawnInterval = 2f; void Start() { InvokeRepeating("SpawnRandomAnimal", startDelay, spawnInterval); } 2. InvokeRepeating("method name", time, delayInterval);

Question 59

# 2.4.2 - Spawn the Animals at timed intervals In our Animal Spawn project, what method should the InvokeRepeating statement be placed into in order to spawn random animals on a timer?

Answer 59

void Start()

Question 60

# 2.4.2 - Spawn the Animals at timed intervals in the InvokeRepeating string, what does 'time' represent?

Answer 60

'time' = the delay before the first call

Question 61

# 2.4.3 - Add collider and trigger components What do we need to add to an object if we want to add collision?

Answer 61

Collider component (Box Collider, Circle Collider, etc.)

Question 62

# 2.4.3 - Add collider and trigger components What does the "Is Trigger" checkbox for and what does it do?

Answer 62

Is Trigger checkbox on a Collider determines whether the collider acts as a trigger. When checked: The collider won’t cause physical collisions but will detect overlapping objects and call trigger events like OnTriggerEnter(), OnTriggerStay(), and OnTriggerExit(). When unchecked: The collider will cause physical collisions and use collision events like OnCollisionEnter().

Question 63

# 2.4.3 - Add collider and trigger components What is a RigidBody component?

Answer 63

A Rigidbody is a component that enables a GameObject to be affected by physics, such as gravity, forces, and collisions. It allows objects to move and rotate realistically within the physics engine.

Question 64

# 2.4.3 - Add collider and trigger components In our feeding animals game, why might we specifically want to add a Rigidbody to our projectile food object, and not the animal objects?

Answer 64

Because we want the projectile to keep moving through the scene, we want Gravity to be turned off. Gravity is a toggle within the Rigidbody component.

Question 65

# 2.4.4 - Destroy objects on collision What is OnTriggerEnter

Answer 65

OnTriggerEnter is a Unity event method called when another collider enters a trigger collider attached to the object (with Is Trigger enabled).

Question 66

# 2.4.4 - Destroy objects on collision What is the syntax for OnTriggerEnter?

Answer 66

void OnTriggerEnter(Collider other)

Question 67

# 2.4.4 - Destroy objects on collision What is Destroy?

Answer 67

Destroy is a Unity method used to remove a GameObject, component, or asset from the scene or memory.

Question 68

# 2.4.4 - Destroy objects on collision What is the syntax for Destroy?

Answer 68

Destroy(gameObject);

Question 69

# 2.4.4 - Destroy objects on collision Describe what is happening in this code: void OnTriggerEnter(Collider other) { Destroy(gameObject); Destroy(other.gameObject); }

Answer 69

// Destroys the object this script is attached to // Destroys the object that entered the trigger

Question 70

# 2.4.4 - Destroy objects on collision Destroy(other.gameObject); - what is this referring to? What does Other stand for in this statement?

Answer 70

refers to the GameObject that owns the collider that triggered the event, telling it to destroy the other object it came in contact with. other is the parameter passed to the method: it's the Collider of the object that entered the trigger.

Question 71

# 2.4.5 - Trigger a "Game Over" message Where can you go in Visual Studio to fix any indentation issues that might be in your code?

Answer 71

Edit > Advanced > Format document

Question 72

# 2.4.5 - Trigger a "Game Over" message What is Debug?

Answer 72

Debug is a Unity class used for logging messages, warnings, and errors to the Console during development. It helps with testing, troubleshooting, and tracking code behavior. Common methods include: Debug.Log("message") – prints a message. Debug.LogWarning("warning") – prints a yellow warning. Debug.LogError("error") – prints a red error.

Question 73

# 2.4.5 - Trigger a "Game Over" message What is Debug.Log

Answer 73

Prints a message to the Console

Question 74

# 2.4.5 - Trigger a "Game Over" In DestroyOutOfBounds.cs, write the else-if condition that checks if the animals reach the bottom of the screen, add a game over message. Use lowerBound for your variable Hint: Objects are moving up or down along the z axis.

Answer 74

void Update() { if (transform.position.z > topBound) { Destroy(gameObject); } **else if(transform.position.z < lowerBound) { Debug.Log("Game Over"); }** }