3 ways to pick up an Item, which is least expensive?

Unity Engine
1

so first way is triggers or collision, second raycast and third player proximity…

i can imagine using an On…Enter function with a collider or trigger would be cheaper as checking a tag or so with a raycast?

but what about checking the distance between the item and the player if its less than … start a pickup dialog?

what are the pros and cons comparing the 3 methods?

the cons i find on the first two methods is 1 using triggers: the trigger are best a bit bigger as the object so you don’t have to “stand on top of them” to collect. i just find it messy having an extra sphere collider or what not as an extra component for this because i still need the mesh collider for the physics…
2 a bit the same problem because i don’t want the player to be to secure in actually having to look with a certain precision to be able to collect

so for now i seem to favour the third, only i was wondering about the cost of keeping track of the player position from the items. they go up in the hundreds if not more eventually… and each one constantly checking for the distance between itself and the player…?
i have all item in a list per level. would it be cheaper to let the player check distance against the items in the list?

2

I don’t think you want to use method 3 with hundreds of object (at least it won’t be optimal) as you are using brute force approach (unless you are using your own spatial tree).

Although I don’t know how the source code of Unity works behind the scenes, I would imagine it uses spatial trees of some kind to make trigger and ray tests extremely quickly. With spatial queries like this most of the objects are rejected from consideration without ever having to be tested. Furthermore, trigger and colliders are hardware accelerated on PhysX hardware too.

I suppose if you don;t like having the extra trigger on the player, you could always switch it round and have the triggers on the pickup item sensitive to the player’s collider. YOu would just need to add a trigger to your pickable prefabs and you are done.

Hope that helps