🎮

Unity Game Development Basics

Jun 15, 2025

View transcript

Overview

This lecture provides a step-by-step, practical introduction to game development in Unity by guiding you through creating a Flappy Bird clone, covering essential Unity concepts, basic programming, and UI setup.

Getting Started with Unity

  • Download and install Unity Hub, then the Unity Editor (2021.3 used) and Microsoft Visual Studio for coding.
  • Create a free Unity account to use the editor.
  • Start a new 2D Core project, name it, and create.

Unity User Interface & GameObjects

  • Unity UI comprises Project, Hierarchy, Inspector, and Scene/Game View panels.
  • Project: stores assets like sprites and scripts.
  • Hierarchy: lists all GameObjects in the current scene.
  • Inspector: modifies selected GameObject's components.
  • Scene/Game View: visualizes and edits the scene.
  • GameObjects are containers with position, rotation, and scale; components add functionality.

Making the Bird Move

  • Add Sprite Renderer and Rigidbody 2D components to the bird GameObject.
  • Add a Circle Collider 2D for collision detection.
  • Create a C# script; use public references to access other components (e.g., Rigidbody2D).
  • Use Update() for per-frame logic; Start() runs once.
  • Detect spacebar press with Input.GetKeyDown(KeyCode.Space) inside an if statement to apply upward velocity.
  • Expose flap strength as a public float variable to adjust in Inspector.

Spawning and Managing Pipes

  • Build pipes with GameObjects, adding Sprite Renderers and Box Colliders.
  • Nest top/bottom pipes under a parent for group movement.
  • Make pipes move left by modifying transform.position in Update(), using Time.deltaTime for frame-rate independence.
  • Use prefabs to create reusable objects; spawn new pipes via a spawner script at timed intervals.
  • Randomize pipe spawn heights with Random.Range.
  • Destroy pipes when they move offscreen with Destroy(GameObject).

Tracking Score and UI

  • Add a UI Canvas and Text object for displaying score; set canvas to scale with screen size.
  • Create a Logic Manager GameObject with a script to track score as an int and update the UI.
  • Use triggers (isTrigger checked) for non-physical collision detection (bird passing through pipes).
  • Reference scripts via tags (e.g., “Logic”) and GameObject.FindGameObjectWithTag for runtime connections.
  • Pass variables as function parameters for flexibility.

Game Over and Restart Logic

  • Implement a Game Over screen UI and a restart button triggering a public function in the Logic script.
  • Use UnityEngine.SceneManagement to reload the current scene when restarting.
  • Show the Game Over screen only when necessary by enabling/disabling the GameObject.
  • Stop gameplay actions after Game Over using a boolean (bool) to track if the bird is alive.

Key Terms & Definitions

  • GameObject — The basic entity in Unity representing objects in the scene.
  • Component — Modular feature that adds functionality to GameObjects.
  • Prefab — A reusable blueprint for GameObjects.
  • Rigidbody2D — Component that gives GameObjects physics properties.
  • Collider/Trigger — Detects collisions; trigger allows overlap detection without physical collision.
  • Script (C#) — Custom code controlling behavior, attached as a component.
  • Update() — Function called every frame.
  • Start() — Function called once at the start.
  • Inspector — Panel to view and edit GameObject components.
  • Time.deltaTime — Ensures smooth, frame-rate-independent movement.
  • Input.GetKeyDown() — Checks for key press in the current frame.
  • Tag/Layer — Identifiers for grouping or filtering GameObjects.
  • Bool — Boolean value; true or false.

Action Items / Next Steps

  • Add Game Over for the bird going offscreen.
  • Fix score updating after Game Over.
  • Add sound effects via an Audio Source and script reference.
  • Use Particle System for effects (e.g., clouds).
  • Animate the bird’s wings using the Animation window.
  • Create a title screen as a separate scene and add it to build settings.
  • Implement high score saving with PlayerPrefs and display it on UI.
  • Try remaking another simple game (e.g., Pong, Breakout) to reinforce concepts.

Full transcript