checking if any objects are within a certain range

Unity Engine
1

Hi there,

how can i check if any objects are within a certain range of other objects?? Do i need to cycle thru all active objects and check it “manually” or is there some builtin function which returns objects within that range??

thanks in advance,
cheers,
Ello

2

You could use a spherical collider.

3

Try that out.

4

thank you very much

5

CheckSphere is pretty cool, I need to go through the docs and see what else I have missed.

6

i still have an issue… seems like CheckSphere also reacts to its own Collider… i am using this to test

if (Physics.CheckSphere (transform.position, 1.0f, kDefaultRaycastLayers))	baseScale*= 0.9f;

but my objects are all scaling down as if there where everywhere colliders.

any ideas?

cheers,
Ello

7

CheckSphere does not require a collider at all. It can be done from an entirely different script/gameObject.

If you have a SphereCollider already you should probably use JRavey’s idea, and set that Collider to IsTrigger, and then use OnTriggerEnter to set events.

8

thanky for your input… i still have no success with it.

here is my code for creating the objects:

using UnityEngine;
using System.Collections;

public class createLifeforms : MonoBehaviour {

	private GameObject s;
	private ArrayList myNodes;
	int _w = 200;
	int _number = 100;
	void Start ()
	{
		
		for (int i = 0; i < _number; i++)
		{
			myNodes = new ArrayList();
			s = GameObject.CreatePrimitive(PrimitiveType.Sphere);
			s.transform.position = new Vector3 ((Random.value*_w)-_w/2,0,  (Random.value*_w)-_w/2);
			s.AddComponent("lifeform");
			myNodes.Add(s);
		}
	}

	// Update is called once per frame
	void Update () {
		Destroy(this);
		}
}

and this is the code for each object:

using UnityEngine;
using System.Collections;

public class lifeform : MonoBehaviour {

	float offset;
	int _maxScale = 10;
	float baseScale;
	
	void OnTriggerEnter() {
		Destroy(this);
	}
	// Use this for initialization
	void Start () {
		offset = Random.value*360.0f;
		float _s = (Random.value*_maxScale)+1;
		baseScale = _s;
		collider.isTrigger = true;
	}
	
	float _speedX = 0.1f*(Random.value*5-2.5f);
	float _speedZ = 0.1f*(Random.value*5-2.5f);
	// Update is called once per frame
	void Update () {
		Color col = renderer.material.color;
		col.r = 1.5f + 1.5f*Mathf.Sin(Time.time + offset);
		col.g = 0.0f;
		col.b = 0.0f;
		renderer.material.color = col; 
		_speedX += 0.2f*Random.value-0.1f;
		_speedZ += 0.2f*Random.value-0.1f;
		_speedX = Mathf.Clamp(_speedX,-2.5f,2.5f);
		_speedZ = Mathf.Clamp(_speedZ,-2.5f,2.5f);
		transform.Translate((0.1f*_speedX), 0,  (0.1f*_speedZ));
		Vector3 position = transform.position;
		position.x = Mathf.Clamp(transform.position.x, -200f,200f);
		position.z = Mathf.Clamp(transform.position.z, -200f,200f);
		transform.position = position; 
		Vector3 scale = transform.localScale;
		scale.x = scale.y = scale.z = baseScale*(0.5f+col.r*0.25f);
		transform.localScale = scale;
		if (position.x<-100) _speedX += 0.1f*Random.value;
		if (position.z<-100) _speedZ += 0.1f*Random.value;
		if (position.x>100) _speedX -= 0.1f*Random.value;
		if (position.z>100) _speedZ -= 0.1f*Random.value;
	}
}

i guess its just some beginner fault on my side…

cheers,
Ello