Unity 2D Cheat Sheet

Project Setup


         New Project > 2D Template

Create 2D project with correct settings


         Edit > Project Settings > Graphics

Configure rendering settings


         Window > Rendering > Lighting

Access lighting window


         Edit > Project Settings > Physics 2D

Configure 2D physics settings

GameObject Basics


         GameObject.Find("ObjectName")

Find GameObject by name


         GameObject.FindWithTag("Player")

Find GameObject by tag


         Instantiate(prefab, position, rotation)

Create GameObject instance


         Destroy(gameObject)

Destroy GameObject


         Destroy(gameObject, 2f)

Destroy after 2 seconds


         gameObject.SetActive(false)

Deactivate GameObject


         DontDestroyOnLoad(gameObject)

Persist between scenes

Transform & Position


         transform.position

World position (Vector3)


         transform.localPosition

Position relative to parent


         transform.position = new Vector3(0, 0, 0)

Set position


         transform.Translate(Vector3.right * speed * Time.deltaTime)

Move GameObject


         transform.rotation

Rotation (Quaternion)


         transform.Rotate(0, 0, 90)

Rotate 90 degrees on Z axis


         transform.localScale

Scale (Vector3)


         Vector3.Distance(pos1, pos2)

Distance between positions

Sprites


         SpriteRenderer

Component to render sprites


         GetComponent<SpriteRenderer>()

Get SpriteRenderer component


         spriteRenderer.sprite = newSprite

Change sprite


         spriteRenderer.color = Color.red

Tint sprite color


         spriteRenderer.flipX = true

Flip sprite horizontally


         spriteRenderer.sortingLayerName = "Foreground"

Set sorting layer


         spriteRenderer.sortingOrder = 10

Set order in layer


         Sprite Editor (Texture Import Settings)

Slice sprite sheets

Rigidbody2D (Physics)


         Rigidbody2D rb

2D physics component


         rb.velocity = new Vector2(x, y)

Set velocity directly


         rb.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse)

Apply force (jump)


         rb.gravityScale = 1f

Gravity multiplier


         rb.bodyType = RigidbodyType2D.Kinematic

Set to kinematic (no physics)


         rb.constraints = RigidbodyConstraints2D.FreezeRotation

Lock rotation


         rb.mass = 2f

Set object mass


         rb.drag = 0.5f

Air resistance

Colliders 2D


         BoxCollider2D

Rectangle collision box


         CircleCollider2D

Circle collision


         PolygonCollider2D

Custom shape collision


         EdgeCollider2D

Line/edge collision


         collider.isTrigger = true

Make collider a trigger


         OnCollisionEnter2D(Collision2D collision)

Called when collision starts


         OnTriggerEnter2D(Collider2D other)

Called when entering trigger


         collision.gameObject.tag

Get tag of collided object

Input


         Input.GetKey(KeyCode.Space)

Check if key is held down


         Input.GetKeyDown(KeyCode.Space)

Check if key was just pressed


         Input.GetKeyUp(KeyCode.Space)

Check if key was just released


         Input.GetAxis("Horizontal")

Get horizontal input (-1 to 1)


         Input.GetAxisRaw("Vertical")

Get vertical input (no smoothing)


         Input.GetMouseButton(0)

Left mouse button (0=left, 1=right)


         Input.mousePosition

Mouse position on screen


         Camera.main.ScreenToWorldPoint(Input.mousePosition)

Convert mouse to world position

Animation


         Animator

Component for animations


         animator.SetBool("isRunning", true)

Set bool parameter


         animator.SetFloat("speed", 5f)

Set float parameter


         animator.SetTrigger("jump")

Trigger animation once


         Window > Animation

Open Animation window


         Window > Animator

Open Animator controller

MonoBehaviour Lifecycle


         Awake()

Called when script instance loaded


         Start()

Called before first frame update


         Update()

Called every frame


         FixedUpdate()

Called at fixed intervals (physics)


         LateUpdate()

Called after all Updates


         OnEnable()

Called when object enabled


         OnDisable()

Called when object disabled


         OnDestroy()

Called when object destroyed

Time


         Time.deltaTime

Time since last frame (framerate independent)


         Time.fixedDeltaTime

Fixed update interval


         Time.time

Time since game started


         Time.timeScale = 0.5f

Slow motion (0 = paused)

Audio


         AudioSource

Component to play audio


         audioSource.Play()

Play audio clip


         audioSource.PlayOneShot(clip)

Play clip once (overlap allowed)


         audioSource.Stop()

Stop playing audio


         audioSource.volume = 0.5f

Set volume (0-1)


         audioSource.loop = true

Loop audio

Camera


         Camera.main

Get main camera


         camera.orthographicSize = 5f

Set camera zoom (2D)


         transform.position = target.position + offset

Follow player (camera script)


         Vector3.Lerp(start, end, t)

Smooth camera movement

UI


         using UnityEngine.UI;

Import UI namespace


         Text textComponent

UI Text component


         textComponent.text = "Score: " + score

Update UI text


         Image imageComponent

UI Image component


         Button buttonComponent

UI Button component


         Canvas

Container for UI elements

Scene Management


         using UnityEngine.SceneManagement;

Import scene management


         SceneManager.LoadScene("MainMenu")

Load scene by name


         SceneManager.LoadScene(0)

Load scene by index


         SceneManager.GetActiveScene().name

Get current scene name

Coroutines


         StartCoroutine(MyCoroutine())

Start coroutine


         IEnumerator MyCoroutine()

Coroutine method signature


         yield return new WaitForSeconds(2f)

Wait 2 seconds


         yield return null

Wait one frame


         StopCoroutine(coroutine)

Stop running coroutine