Basics of Unity Game Engine

1. What is Unity?

Unity is a cross-platform game engine used to create 2D, 3D, AR (Augmented Reality), and VR (Virtual Reality) games and simulations. It’s known for its flexibility, visual editor, and support for multiple platforms — PC, consoles, mobile, and the web.

2. Core Components of Unity

Component	Description
Scene	The environment or level of your game; contains all game objects.
GameObject	The basic unit in Unity — anything in the scene (player, camera, light, enemy, etc.).
Component	Behaviors or properties added to GameObjects (e.g., Rigidbody, Collider, Script).
Transform	Defines position, rotation, and scale of a GameObject.
Prefab	A reusable template for GameObjects. Great for enemies, bullets, etc.
Asset	External resources like textures, sounds, models, and scripts.
Tag and Layer	Used to identify or organize GameObjects in a scene.

3. Programming in Unity

Language: Unity primarily uses C# for scripting.

using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    void Start() {
        // Runs once at the start
    }

    void Update() {
        // Runs every frame
    }
}

MonoBehaviour: The base class for all Unity scripts that interact with GameObjects.

4. Game Physics and Animation

• Rigidbody: Adds realistic physics behavior.
• Collider: Defines shape for physical interactions.
• Animator & Animation: Used for creating movement and transitions between animations.
• Physics Engine: Handles gravity, collisions, and forces automatically.

5. User Interface (UI)

• Canvas: The root of all UI elements.
• UI Elements: Buttons, sliders, text, images, etc.
• Event System: Detects player input (clicks, touches, etc.).

6. Lighting and Cameras

• Directional Light: Mimics sunlight.
• Point Light & Spot Light: Localized light sources.
• Camera: Defines the player’s view in the scene.

7. Scenes and Prefabs

Scenes can represent levels or menus. Prefabs allow you to instantiate multiple copies of GameObjects efficiently.

8. Unity Editor Interface

Window	Purpose
Scene View	Design and edit your level.
Game View	Preview how your game will look when running.
Hierarchy	Displays all GameObjects in the current scene.
Inspector	Shows properties and components of selected GameObjects.
Project Window	Shows all assets in your project.
Console	Displays debug messages and errors.

9. Building and Deployment

Unity can build your project for multiple platforms:

• Windows, macOS, Linux
• Android, iOS
• WebGL
• Consoles (Xbox, PlayStation, Switch — with license)

10. Learning Concepts

• Game Loop: Continuous cycle of updating and rendering.
• Frame Rate: Number of frames per second (FPS).
• Prefabs and Instantiation: Efficiently create multiple similar objects.
• Scripting API: Unity has an extensive C# API for manipulating all game elements.