2D Unity Game

GameObject: Fundamental building block in unity --> Represents every object
Component: Functional pieces of every GameObject. Properties that define the behaviour of a GameObject.
Sprite: 2D graphic object that comes from a bitmap image
- Sprites are made from pixels
- Unit: Unit in unity have no meaning. New assets default to 100 pixel s per unit
Transformations
- Rotate
- Translate
- Scale
Methods are 3D by default. Override 2D versions of methods by appending 2D to the overriden method
Serialize variables in unity: Append SerializeField to variables to allow changing the value in the unity inspector
- Value in the inspector overrides the constant value defined in the code

[SerializeField] float steerSpeed = 1f;

Input System: Convert physical action to game information
- Unity has an old and new system
- Old: Uses string reference to input manager. Values in range [-1, 1].
  - "Horizontal" and "Vertical" Axis defined in your project settings --> We use these string references
- New:
FPS impacts how often the update function is called. FPS and updates are proportional
- Need to multiple each movement by time.deltaTime to make movement framerate independent
Collision:
- Colliders (2D): Detects overlapping colliders
- RigidBody (2D): Causes interaction between colliders in physics engine
- Detect collisions (2D) with OnCollisionEnter2D
Encapsulation with empty objects: TODO:
References: Reference to other GameObject(s)
- E.G. Used to fix camera's positions to player object
Unity Execution Order:
- Physics is fixed
- Late Update:

Mesh Collider (3D) or polygon collider (2D) match the shape of the object the component is attached to
Static colliders : Create motionless objects such as floors using colliders without a RigidBody component
Physics material: Can attach physical properties to collision (e.g. surface materials like ice which are slippery)
Triggers: Triggers are not considered as solid objects but have collision detection
- OnTriggerEnter : Triggers callback event when another collider touches the trigger collider
- Can give objects Tags. The string reference to a tag is checked OnTriggerEnter
OnCollisionEnter : Callback to initiate action on collision (or OnCollisionEnter2D)
See the collision matrix for all the interactions