Unity Basic Course: Adding Scripts

Unity is a powerful engine for game development. In this course, you will explore the basic features of Unity and learn how to add scripts to game objects. The process of adding scripts is an important part of implementing interactions and adding functionality within Unity.

1. Overview of Unity

Unity is a platform that allows for the development of 2D and 3D games, serving as a powerful tool for deployment across various platforms. Unity can create diverse types of content including game videos, virtual reality (VR), and augmented reality (AR).

1.1 Basic Components of Unity

The core components of Unity are as follows:

  • Scenes: Represents each level or environment in the game.
  • Game Objects: All elements within a scene, such as 3D models, cameras, lights, etc.
  • Components: Functions and properties given by adding to game objects. Scripts are a type of component.
  • Scripts: Used to write game logic.
  • Assets: Refers to all files used in the project such as scripts, audio, textures, 3D models, etc.

2. Installing Unity

To use Unity, you first need to install the Unity Editor through Unity Hub.

  1. Download and install Unity Hub.
  2. Run Unity Hub and navigate to the ‘Installs’ section.
  3. Click the ‘Add’ button to add a new version of Unity and select the necessary modules for installation.
  4. Now to create a project, navigate to the ‘Projects’ section or click the ‘New’ button to create a new project.

3. Starting a New Project

When you start a new project, a default scene is created automatically. Here, you can add game objects and write scripts to implement interactions.

  1. Select ‘New’ in Unity Hub to create a new project.
  2. Select a 2D or 3D project template and specify a project name and save location.
  3. Once the project is created and the Unity Editor opens, the default scene is displayed.

4. Adding Game Objects

Game objects represent all entities within Unity. To add a new game object, follow these steps:

  1. From the top menu, select GameObject > 3D Object to add various objects (e.g., Cube, Sphere, Plane).
  2. Check the game objects in the current scene in the Hierarchy panel to understand the nature of the added objects.

5. Adding Scripts

Scripts in Unity are written in C#. Here’s how to add a script:

  1. In the Project panel, select Assets > Create > C# Script.
  2. Name the script and double-click to open it in a code editor like Visual Studio.

5.1 Basic Script Structure

using UnityEngine;

public class MyFirstScript : MonoBehaviour
{
    void Start()
    {
        // Called when the game starts
        Debug.Log("Hello, Unity!");
    }

    void Update()
    {
        // Called every frame
        transform.Rotate(Vector3.up, 100 * Time.deltaTime);
    }
}

The code above shows the basic structure for writing scripts in Unity. By inheriting from the MonoBehaviour class, you can create scripts that add functionality to game objects.

5.2 Adding Scripts to Game Objects

After writing a script, you need to add it to a game object:

  1. Select the game object to which you want to add the script in the Hierarchy panel.
  2. In the Inspector panel, click the Add Component button, and enter the name of the script you created to add it.

6. Managing Variables and Data

Data used within scripts is managed through variables. Variables are used to store states, and Unity supports various types.

6.1 Basic Data Types

The basic data types used in C# are as follows:

  • int: Stores integer values.
  • float: Stores numbers with decimals.
  • bool: Stores true or false values.
  • string: Stores string data.

For example, int score; declares an integer variable to store the game score.

6.2 Variable Accessibility

In Unity, variables can be managed with various accessibility types:

  • public: Accessible from other scripts or the Unity Editor.
  • private: Accessible only within that script.
  • protected: Accessible within that script or child scripts.

7. Methods and Functions

A method is a block of code that performs a specific task. Unity uses various methods to define game logic.

7.1 Using Basic Methods

The following example demonstrates how to implement a method with parameters:

public void Move(Vector3 direction)
{
    transform.Translate(direction * Time.deltaTime);
}

7.2 Event Methods

In Unity, there are event methods that are automatically called at specific points in the game. For example:

  • Start(): Called once when the script is activated.
  • Update(): Called every frame.
  • OnCollisionEnter(): Called when colliding with another game object.

8. Physics Engine and Collision Handling

By using Unity’s physics engine, you can achieve realistic movements and collisions.

8.1 Adding Rigidbody Component

To give a game object physics effects, you need to add a Rigidbody component:

  1. Select the game object, then click Add Component in the Inspector panel.
  2. Search for and add Rigidbody.

8.2 Handling Collisions

void OnCollisionEnter(Collision collision)
{
    Debug.Log("Collision detected: " + collision.gameObject.name);
}

9. Adding UI Elements and Connecting Scripts

The user interface (UI) of the game is an important element for player interaction. Unity makes it easy to implement UI.

9.1 Creating a UI Canvas

A canvas is needed to add UI elements:

  1. In the Hierarchy panel, select UI > Canvas to create a canvas.
  2. Add UI elements like buttons and text within the canvas.

9.2 Handling Button Click Events

You can define reactions to button clicks in a script:

using UnityEngine;
using UnityEngine.UI;

public class UIButtonHandler : MonoBehaviour
{
    public Button myButton;

    void Start()
    {
        myButton.onClick.AddListener(OnButtonClick);
    }

    void OnButtonClick()
    {
        Debug.Log("Button clicked!");
    }
}

10. Adding Animations

You can add animations to bring life to the game. Unity allows for easy implementation through its animation system.

10.1 Creating Animation Clips

To create animation clips:

  1. Open the Animation window and select the game object to which you want to add animations.
  2. Click the Create button to generate a new animation clip.

10.2 Using Animation Triggers

using UnityEngine;

public class CharacterAnimator : MonoBehaviour
{
    private Animator animator;

    void Start()
    {
        animator = GetComponent();
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            animator.SetTrigger("Jump");
        }
    }
}

11. Building and Deploying the Game

The final stage of game development is to build and deploy the game. Unity provides functions to deploy across various platforms.

11.1 Setting Up the Build

To build the game:

  1. Select File > Build Settings from the top menu.
  2. Select the target platform and click Build.
  3. Select a location to build and create an exe file or app.

11.2 Deploying

The generated files can be used to deploy across various platforms. You can deploy tailored to platforms including web, PC, and mobile.

12. Conclusion

In this course, we explored the basic concepts of Unity and how to add scripts. By using scripts, you can add interactions and logic to create a richer experience in your game. Game development with Unity offers limitless possibilities.

Now, combine various features and elements to create your own fun game!