Creating scripts for each objects behaviours instead of writing everything in the object script body

Question

I have two game objects in my example scene. Both needs to rotate constantly with a specific speed on their local space. They are just simple coins which purpose is to be collected by the player. Instead of writing the rotation script inside each Update() method, I created a script called Rotator that makes the object which it's attached to actually rotate.

I have attached the component Rotator to each object and it works just fine. Now I have two game objects which have a component called Rotator that will make them rotate.

This is the Rotator class:

using UnityEngine;

public class Rotator : MonoBehaviour
{
    [SerializeField][Range(5, 10)]
    private int _rotationSpeed = 5;

    [SerializeField]
    private float _xAxes = 0;
    [SerializeField]
    private float _yAxes = 0;
    [SerializeField]
    private float _zAxes = 0;

    void Update()
    {
        transform.Rotate(new Vector3(_xAxes, _yAxes, _zAxes) * _rotationSpeed * Time.deltaTime);
    }
}

I think that in this way the creation flow for my game objects is much easier and modular than writing the same code above inside each element that should rotate.

My question is: will this have an impact on performance? Is it a bad idea to split behaviors into small pieces or components and then adding them to each game object that require them? Or is better, in the case of just a simple rotation, to write that line of code directly inside one game object script?

For example, I have now another game object called Player that needs to rotate on himself as well. This game object as attached already another script called PlayerController that handle the player movements by keyboard inputs. I can write this part...

        transform.Rotate(new Vector3(_xAxes, _yAxes, _zAxes) * _rotationSpeed * Time.deltaTime);

...inside the PlayerController's update() method, or, like I think is better, attach the Rotator script to it. In the last case, I will have a game object with two components:

• PlayerController
• Rotator

Of course, this is just an example, I don't want my player to keep spinning on himself for real, is just to explain my point of view.

So, in the end, I need to understand if this is a good practice, even if is a small line of code like the rotation is worth to create a component? And I'm referring to behaviors that are needed by more than one object, of course, I know that if it's a one-only case, it makes more sense to write it directly in the script which is already attached to the game object in question.

Long post, hope I was clear enough. Thank you all!

Answer 1

The way you do it is the way it should be done. The idea of unity is to use small modular components which can be reused. However having a lot of update functions can have a performance impact, especially if you use Mono and not IL2CPP.

But there are multiple solutions to this.

• Use IL2CPP to remove the "virtual" call layer between C# (your code) and c++ side (engine code).
• Write a behaviour manager which updates all of your scripts from the c# side.
• Look at the Entity Component System and iterate over everything which needs to be rotated in one "Update function".

We actually released a game where rotating crystals had a CPU performance impact. In the end we calculated the LocalRotation value only once per frame and distributed it to all crystals.