Unity - Check if sprite is within range around player

Question

I need to know if a sprite is within range (circle or square doesn't matter) around the player. If the sprite is, let's say, 100 blocks away from the player, I will disable it. This wouldn't be too much of an issue, just compare positions and you're done. However, my game is a tile based game and I want the world to be as big as possible, which will result in millions of sprites.

I could also add a overlapcicle2D, but the problem is this these objects can't have a collider, since they could be walkable.

So how can I check if the millions of sprites are in range of the player, without lowering performance?

Alternatively, I could add occlusion culling. But how do you do this with sprites?

Answer 1

You may not need to include Occlusion Culling for a 2D game in Unity.

Unity has a thing called FrustumCulling that hides any object not in view of the camera. In a 3D game, this isn't always ideal because the frustum doesn't account for distance, meaning that the game would still do things like render rooms behind doors that you can't technically see. However, in a 2D game, you don't need to worry about that, because it's 2D, there's literally no distance to worry about. So, assuming that "100 blocks away from your player" actually means "Outside of the camera view", they're possibly already being culled anyway.

Answer 2

If you're simply trying to minimize resource impact, @DisturbedNeo is right on the money. If there are other reasons you'd like to do this, you could always use a VERY large collider and check for objects inside of it that meet a certain tag criteria.