RaycastHit2D vs OnTriggerEnter2D - unity3d

Question

In my game you can use, axes, pickaxes, hoes, etc. Each to gather a different type of material (ore, wood, crops, etc).
My old system I just set a tiny collider on the tile in front of my player, and then in OnTriggerEnter2D on my nodes, trees, farm-tiles, etc. I checked what category of my Active Item that was entering (below example on my mining-nodes):
void OnTriggerEnter2D(Collider2D other)
{
if(other.gameObject.CompareTag("ActiveItem"))
{
ItemObject activeItemObj = GameManager.manager.activeItem.GetComponent<InventoryItem>().item;
if(activeItemObj.category == "pickaxe")
{
if (!isHit)
{
hit();
}
}
}
}
However this always felt kind of ugly, plus no matter how small the "front collider" is, there is always a chance to hit the tile intersection and hit as many as 4 tiles at the same time.
So instead I wanted to use RayCastHit2D, so I created these methods in my PlayerController Script:
public GameObject GetTileInFront()
{
Vector2 frontRay = new Vector2(transform.position.x + lastMove.x, transform.position.y + lastMove.y + 0.5f);
RaycastHit2D hit = Physics2D.Raycast(frontRay, Vector2.zero);
if (hit.collider != null)
{
Debug.Log("Target Position: " + hit.collider.gameObject.name);
return hit.collider.gameObject;
}
return null;
}
public void ActionInFront(string activeItem)
{
if (activeItem.Equals("pickaxe"))
{
if (GetTileInFront().CompareTag("Node"))
{
GetTileInFront().GetComponent<NodeManager>().hit();
}
}
}
Now I obviously need to create checks like this for every type of tool/tile.
Which leads me to my question:
Which of these 2 methods would be better for performance? I am completely self tought so I always worry I am making some obvious blunder that I cant see.
I definently like the precision of the RayCast better (even though it forces all my colliders to be at least 1x1 in size due to checking 1 tile in front).

Answer 1

Your solution looks OK to me!
Raycasts have the potential to be abused to the point where they're very expensive. The three things you'll want to be mindful of:
How long is the raycast? Keeping it under a tiles length should be good in your case.
What types of geometry is in your scene?: Mesh colliders can cause Raycasts to chug, but in a 2D game where I imagine everything is either a square or a circle you should be good.
How frequently do they occur? Calling a Raycast every frame can be rather expensive, but only calling it when your player is doing the action should be fine.
You mentioned that you were worried your solution will force your colliders to be at least 1x1, but there are ways to get around that. Right now what you're doing is just checking right at a point in front of your player. Instead you may want to consider casting a ray from the player in that direction and it could hit anything a long the way, even if it's smaller than a 1x1 tile. You can do this by changing the second argument of your raycast to something like this:
Physics2D.Raycast(transform.position, Vector2.up * .5f);
The Raycast function takes the point it will be shot from as the first argument, and the direction/length as the second argument (leaving the length 0 like did will just check the point at the first argument).
It's worth noting that if you try to do this with your current solution, all that will happen is that you're character will try to mine himself as it will be the first thing the ray hits! You'll need to add a LayerMask to your raycast to determine what the ray can and can't hit (or if you're lazy, just make sure the ray starts from a point outside the player's collision).