Find Nearby Objects using CullingGroup

An article by mgear    3 Comments

Saw this tip at #UniteKL18, fast way to get nearby objects using CullingGroup!
(main image with 5000 gameobjects, searching objects within 3m radius)

example source code:
https://github.com/UnityCommunity/UnityLibrary/blob/master/Assets/Scripts/Docs/UnityEngine/CullingGroupExample.cs

my example project:
https://github.com/unitycoder/GetNearestObjectsWithCullingGroup

Some notes on that:
– You need to have MainCamera in the scene (as it uses that in “cullGroup.targetCamera = Camera.main;”)
– You need to set proper bounds for your objects, i’m currently doing that inside that for-loop (see b.position=.. and b.radius=..)
– i’m using array of Renderers to keep track of spawned objects (just to make it easy to change color without GetComponent<Renderer>), but you might want to use List, so that can add/remove objects there easily.
– I’m spawning objects on 2D circle, but this would work in 3D too

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TODO
– Compare speed with OnTriggerEnter, Physics.OverlapSphere, BruteForce LINQ distances query, KD/QuadTree
– Test how this works with moving objects? (to get closest enemies for player..)
– Test how to get closests objects to 2 points? (probably cannot easily?)

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Can also check which objects are outside camera view: