UNITY | PROJECT | 2D PlatFormer | 4. Score System

“PlayerScore” Script

• create timeLeft & playerScore
• in Update() method,
  • make timeLeft pass by using Time.deltaTime
  • create an if statement
    • when the time reaches approximately 0, load the scene again
• in Awake() method,
  • temporarily, set the time into 5

“Player” Inspector

 

Time is passing

 

Creating “EndLevel”

• create EndLevel from empty gameObject
  • add Box Collider
    • check is Trigger to make it as Trigger Collider
  • add RigidBody2D
    • set Body Type as Static
      • to make the gameObject immovable
      • the least resource-intensive body type
      • only collides with Dynamic RigidBody2D
      • Having two Static RigidBody2Ds colldie is not supproted

“PlayerScore” Score

• create a Function, CountScore(),
  • update playerScore by calculating with timeLeft
  • create OnTriggerEnter2D()
    • put CountScore() in to make it activated when collisions happen

 

End Level

Creating UI

 

“PlayerScore” script

• create GameObject variables for UIs
• in Update() method,
  • use text property in UIs by using GetComponent()

 

UI Working

UNITY | PROJECT | SPACE SHOOTER 2D | 5. Enemy Bullet & Enemy Shooting

Adding “EnemyBullet” Sprite to the scene to configure

Creating & Adding “EnemyBullet” Script

“EnemyBullet” Script

• Create Variables for “speed”, “direction”, “flag”
• Create a Function to set the Bullet’s Direction, “SetTheDirection(Vector2 direction)”
  • Be careful not to be confused with the names of variable “direction”
    • to differentiate them, put “this.” in front of “direction”(not the argument)
  • normalize the vector to get purely a direction (to make the computing correct and simple)
  • set the flag(the boolean variable) as “True” to activate the codes in “Update()” method
• In “Update()” method
  • the codes will be activated when the flag is set to “True”
  • the position of the bullet is updated every frame by calculating “transform.position” with “direction(Vector2, the result from “SetDirection()”)’
  • if a bullet goes out of the screen, Destroy it
• In “Awake()”
  • every code in “Awake()” is activated before the game starts
  • before the game starts, set “speed” and “ready” with default values

 

Creating “EnemyBullet” Prefab

 

Add “Enemy” Prefab temporally to configure

 

Adding “EnemyGun” to “Enemy” by creating Empty GameObject | Adding “EnemyGun” Script

 

“EnemyGun” Script

• Add a public GameObject variable to use EnemyBullet prefab as a component
• Create a Function to fire bullets from Enemy, “FireEnemyBullet()”
  • get a reference of “Player” by using “GameObject.Find()”
  • the way of detecting a GameObject, “if(gameObject != null)”
  • if “Player” is detected, a bullet is instantiated and its initial position is set
  • how to calculate an aiming direction: Vector – Vector
  • to use “SetDirection()” method of “EnemyBullet” Class, use “GetComponent()” towards “bullet”
• In “Start()” method
  • make “FireEnemyBullet()” activated after 1 second, by using “Invoke()”

 

Don’t forget to add the reference in the Inspector

 

Applying Changes to Prefab

• To apply changes on the prefab, Don’t forget to push “Apply” button in the Inspector

 

Enemies Spawning, Moving, and Shooting

UNITY TUTORIAL | SCRIPTING | Awake() and Start()

Awake()

• Awake() is called first even if the script component is not enabled
• Awake() is best used for setting up any references between scripts and initialization

Start()

• Start() is called after Awake() immediately before the first Update()
• Start() is called only if the script component is enabled
• Start() is used for anything we need to occur
• Start() is only called once in the life time of a script on a gameObject
• It is impossible to repeat Start()
• all of the codes in Start() are called on the first frame that the script is active

Example)

• Awake()
  • set ammo for “enemy” gameObject
• Start()
  • allow “enemy” to shot

Awake() | Start()

Awake() called

Awake(), Start() called