Scripting in Unity

Scripting is what brings your Unity games to life. While GameObjects and Components define your game’s structure, scripts define its behavior. Unity uses C# as its primary scripting language, providing a powerful and flexible way to control objects, implement game mechanics, and handle user input.

Introduction to C# for Unity

C# (C Sharp) is a modern, object-oriented programming language that is easy to learn and widely used in the gaming industry. In Unity, C# scripts are used to:

• Control object behavior and interactions.
• Handle physics and collisions.
• Manage UI and game state.
• Respond to player input and events.

Each script in Unity is typically attached to a GameObject and works as a Component, just like built-in components such as Colliders or Renderers.

Creating and Attaching Scripts to GameObjects

Adding custom behavior to objects in Unity involves creating a C# script and attaching it as a component. Here’s how:

1. Right-click in the Project window and select Create > C# Script.
2. Give the script a descriptive name, like PlayerController.
3. Double-click the script to open it in your IDE (e.g., Visual Studio or Rider).
4. Drag the script onto a GameObject in the Scene to attach it.

Once attached, Unity automatically recognizes your script as a Component, and you can customize its variables in the Inspector if they are public or marked with [SerializeField].

MonoBehaviour Lifecycle Methods (Start, Update, etc.)

Every Unity script that inherits from MonoBehaviour can use special lifecycle methods that Unity calls automatically. Some of the most common methods include:

• Start(): Called once before the first frame update, perfect for initialization.
• Update(): Called every frame, ideal for checking input and continuous behavior.
• FixedUpdate(): Called at fixed intervals, used for physics calculations.
• OnCollisionEnter(): Triggered when the GameObject collides with another object.

Understanding the MonoBehaviour lifecycle is crucial for designing predictable and efficient game logic.

Handling Input and Basic Player Movement

Unity provides an Input System to capture player interactions. The simplest way to handle input is using the Input class in your Update() method. Here’s an example of basic player movement:

using UnityEngine;

public class PlayerController : MonoBehaviour
{
    public float speed = 5f;

    void Update()
    {
        float moveX = Input.GetAxis("Horizontal");
        float moveZ = Input.GetAxis("Vertical");

        Vector3 movement = new Vector3(moveX, 0, moveZ) * speed * Time.deltaTime;
        transform.Translate(movement, Space.World);
    }
}
        

In this script:

• Input.GetAxis("Horizontal") reads A/D or Left/Right Arrow keys.
• Input.GetAxis("Vertical") reads W/S or Up/Down Arrow keys.
• The Transform component is used to move the GameObject in 3D space.

Conclusion

Scripting in Unity allows you to transform static scenes into dynamic, interactive games. By learning the basics of C#, MonoBehaviour lifecycle, and Input handling, you gain the ability to create responsive gameplay and control every aspect of your GameObjects.