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 | PROJECT | SPACE SHOOTER 2D | 2. Player Input Movement

SPACE SHOOTER 2D

2. Player Input Movement

Player Control Script

• Creating & Adding “PlayerControl” script

Player Control Script | Update() | Input.GetAxisRaw()

• setting “speed” variable as public to see in the inspector
• In “Update()”
  • set horizontal & vertical input by using Input.GetAxisRaw()
    • with Input.GetAxisRaw(), the values will be -1, 0 or 1
  • with the two inputs, make “direction”
    • by adding “.normalize”, make a unit vector
  • add a customized fuction “Move()” to move “Player”
    • we need this fuction in “Update()” because “Player”‘s position must be changed and detected every frame

 

Player Control script | Move() | Vector2 | Camera.main.ViewportToWorldPoint()

• to limit the Filed where “Player” can move, get the screen size by using “Camera.main.ViewportToWorldPoint()”
  • ViewPort has a range (0, 0) to (1, 1)

 

Player Control script | Move() | transform.position | Mathf.Clamp()

• get the Player’s current position with “transform.position”
  • transform.position of the gameObject this script is attached to
• calculate the new position in “currentPosition” variable
  • with “speed” variable, we can change the speed of “Player”
    • “direction” is the normalized vector2
    • “Time.deltaTime” is very important with this, we smooth the movement

without “Time.deltaTime”, the value(“direction”) is almost (0, 0), (1, 0)……

 

Setting Player’s Speed | Public Variable

 

Player Input Movement

Player Input Movement | without Time.deltatime

• without “Time.deltaTime”, “Player” moves too dynamically