GameObjects & Components

GameObject

Base class for all entities in Unity Scenes, called GameObjects. Let's take a look at some things we can do with them.

Accesing the gameObject name:

void start() {
    Debug.Log(gameObject.name);
}

To call outside GameObjects, we have to declare the GameObject variable:

public GameObject myCube;

void start() {
    Debug.Log(myCube);
}

To search for a game object:

public GameObject SearchingCubes;

void start() {
    SearchingCubes = GameObject.find("cube");
}

If there are more objects, it's possible to search for them using tags, and add them to array.

public GameObject[] cubes;

void start(){
    cubes = GameObject.FindGameObjectsWithTag("Redcubes");
}

Components

A component is a base class for everything attached to GameObjects.

For this example I will access the component transform of the GameObject through the script.

( ! ) Notice that the script.cs is now a component of the GameObject, so now I can call it by just writing gameObject.

public class MyComponent : MonoBehaviour {
    void Start() {
        Debug.Log(gameObject.transform.position.x);
    }
}

Example: Calling only x and z.

public class MyComponent : MonoBehaviour {
    void Start() {
        float x = gameObject.transform.position.x;
        float z = gameObject.transform.position.z;
        Debug.Log($"{x + z}");
    }
}

This way only works if the script is a componet of the same GameObject. To know the transform values of another GameObject, like a Camera, we need to save that GameObject to a variable first. This script will return the x position of myCameraTransform.

public class MyComponent : MonoBehaviour {
    public Transform myCameraTransform;

    void Start() {
        Debug.Log(myCameraTransform.position.x);
    }
}

Example: Enabling the component BoxCollider. In this case, the component will be assigned automatically through the script with GetComponent<BoxCollider>().

public class MyComponent : MonoBehaviour {
    public BoxCollider myCollider;
    // Start is called before the first frame update
    void Start() {
        myCollider = GetComponent<BoxCollider>();
        myCollider.enabled = true;
    }
}

( ! ) GetComponent<>(); works for all components.