UNITY | PROJECT | 2D PlatFormer | 5. Collectables

Creating “Coin”

• create Coin
  • add Circle Collider 2D
    • make it Trigger Collider by checking Is Trigger
  • add RigidBody2D
    • make it Static Collider

 

“PlayerControl” Script

• in OnTriggerEnter2D() method,
  • if a collision with Coin happens
    • add score by 10
    • destroy the gameObject itself (=Coin)
  • OnTriggerEnter2D vs OnCollisionEnter2D
    • When there are TriggerColliders, use OnTriggerEnter2D
    • When there are normal Colliders, use OnCollisionEnter2D

 

Collecting Coin Working

 

ProjectSetting | Physics2Dsetting

• Uncheck “Queries Start in Colliders”
  • I guess Query there means anything to detect in physics such as RayCast
  • with that option checked, RayCasting starts from the inside of collider attached to GameObjects
  • with that option unchecked, RayCasting Starts from the collider attached to GameObjects

 

“Enemy” Inspector

• Tag as “Enemy”
• Set the layer as “Default”

 

“PlayerControl” Script

• create a function, PlayerRayCast(),
  • attach RayCast by using RayCastHit2D, and Physics2D.RayCast(vector2 origin, vector2 direction)
  • create an if statment,
    •  give Player jump by using GetComponent<RigidBody2D>.AddForce()

 

“PlayerControl” Script

• Add PlayerRayCast() function in Update() method

 

Jumping on “Enemy”

 

Experiment | Layer : Ignore RayCast

• put Enemy back in IgnoreRayCast Layer

 

RayCasting Not Working

• with the option, “Queries Start in Colliders” unchecked, Enemy is moving correctly because RayCasting Starts from the exterior of Collider attacked to Enemy
• with the fact that Enemy belongs to Ignore RayCast layer, the RayCasting feature is not working

 

“EnemyControl” Script

• in Update() method,
  • with the Raycasting feature, Enemy detects other objects horizontally
  • in the horizon, if Enemy collides with Player, Destroy Player

 

Jumping on “Enemy”

 

“PlayerControl” Script

• in PlayerRayCast(),
  • set if statements with the conditions,
    • if Player hit anything, and if it is Enemy, make Player jump on Enemy
    • if Player hit anything, and if it is not Enemy, set the flag for jump as true

“Player” can jump anywhere but “Enemy”

 

 

WEEK3 |Unity 2D Physics | Prefabs, Collider

Prefab

• a prefabricated gameObject
• a gameObject we have configured the way we want, then saved as a prefab
• easily adding instances of the prefab to a scene in the editor
• easily adding instances of the prefab to a scene from a script(spawning)

Prefabs | Sprite

Prefabs | Sprite change

 

Component added to Prefab

 

Component applied to GameObject from Prefab

Component applied to GameObject from Prefab

RigidBody2D | GetComponent() | Rigid

Script attached to a GameObject

Script working in a GameObject

Inspector | Prefab Apply

Prefab change Applied

 

Collision Detection

• Detecting collisions between gameObject
• if both game objects have 2D collider, the Physics 2D engine automatically does collision detection

Edge Collider

Box Collider

Physics Material

Physics applied to Collider

Collision Resolution

• Doing something based on the fact that a collision has been detected
• 2D Physics materials for the game object colliders determine how the Physics 2D engine resolves the collision(Friction/Bounciness)
• Additional collision resolution by ourselves is possible

OnCollisonEnter2D

OnCollisionEnter2D