Trigger in Unity 3D project working not constantly

Question

There is a remake of the Snake game. The snake's head is a trigger, and the apple uses only a collider. Now OnTriggerEnter() does not work every time - the snake's trigger have to enter several times into apple's body to get it.

There is code used for eating:

void Head.OnTriggerEnter(Collider col)
{
    if(col.CompareTag("Food"))
    {
        gameController.FoodEated();
    }
}

public void GameController FoodEated()
{
    Destroy(currentFood);
    InitializeMeal();
    head.GrowUp();
}

void GameController.InitializeMeal()
{
    currentFood = (GameObject)Instantiate(foodPrefab, FindFreeSpace(), Quaternion.identity);
}

And there is some kind of magic: The first apple could be eaten normally, but the snake can walk through the second apple a few times before the apple will be activated.

I tried every trigger functions and none of them are working. http://www.youtube.com/watch?v=z_UQi7SGOLw - video of a bug. The snake is going through the apple for 3-4 frame updates. I have another idea for realizing an apple, but a trigger is more appropriate, I think.

Answer 1

If your snake moves too fast and the apple collider is too small than I guess that Unity's engine can sometimes miss collisions.

If on the snake you have a Rigidbody component than you can increase collision detection quality by changing "Collision Detection" from "Discrete" to "Continues" or "Continues Dynamic".

Answer 2

As you can see on the video above, my snake is growing by creating a tailelement at the current transform.position. TailElement starts moving when the distance between last two tail elements is more or equals 1.

I just tried to decrease the radius of the head's collider by 10% and now the tail element is not collider during the movement of snake. Now it works fine.