Detecting a Button Press While in a Trigger

Questions & Answers
1

For practice, I’m trying to detect a button press when within a trigger (like if you were to speak to an NPC in a game), but, for some reason, it isn’t working. I can get an event to happen when I enter the trigger and I can get an event to happen when I press the button, but I can’t get an event to happen when I am within a trigger AND pushing the button. Here’s the code for reference:

    void OnTriggerEnter(Collider other)
    {
        if (Input.GetKeyDown("space") && other.tag == "TalkCylinder")
        {
            Debug.Log("Talking");
        }
    }
2

OnTriggerEnter will be called only the time when two colliders overlap. That means, it will be next to impossible to take input at the exact frame this function is called (unless you are spamming the “space” key).

Move your code to OnTriggerStay, which will be called every frame after the colliders have made contact, and then you can check for input from the user.

void OnTriggerStay(Collider other)
     {
         Debug.Log("This will be called every frame");
         if (Input.GetKeyDown("space") && other.tag == "TalkCylinder")
         {
             Debug.Log("Talking");
         }
     }
3

Don’t use Input in OnTriggerStay. It’ll give you some weird Input behaviour and so on. OnTriggerStay is runs like FixedUpdate, not each frame.
Check for Input in Update instead and use OnTriggerStay to toggle a bool saying if it should be checking for Input or not.

For Example:

    [SerializeField]
    private bool _canPickUpCoin;

    private void Update()
    {
        if (_canPickUpCoin)
        {
            if (Input.GetKeyDown(KeyCode.E))
            {
                _canPickUpCoin = false;
                // your code          
            }
        }  
    }

    private void OnTriggerEnter(Collider other)
    {
        if (other.TryGetComponent<Player>(out var player))
        {           
            _canPickUpCoin = true;
        }
    }

    private void OnTriggerExit(Collider other)
    {
        if (other.TryGetComponent<Player>(out var player))
        {
            _canPickUpCoin = false;
        }
    }