How to set collisions on script created objects

Hello!

I would like to detect collisions on objects created from script.
Is it possible to create an object and to set a Collision behavior (OnCollisionEnter) to the object created directly by script?

This does not work:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Button : MonoBehaviour {
6.  
7.     BoxCollider collider1;
8.  
9.  
10.  
11.     // Use this for initialization
12.     void Start () {
13.  
14.  
15.         //Button LEFT
16.         GameObject cube = GameObject.CreatePrimitive(PrimitiveType.Cube);
17.        
18.         cube.transform.position = new Vector3(20, -30, 220);
19.         cube.transform.localScale = new Vector3(20, 20, 5);
20.         Rigidbody cuberigidbody = cube.AddComponent<Rigidbody>();
21.         cuberigidbody.useGravity = false;
22.         cuberigidbody.isKinematic = true;
23.  
24.         collider1 = cube.AddComponent<BoxCollider>();
25.         collider1.isTrigger = true;
26.        
27.        
28.  
29.     }
30.  
31.  
32.      void OnCollisionEnter(Collision collision)
33.     {
34.         UnityEngine.Debug.Log("S");
35.     }
36.  
37.  
38.     // Update is called once per frame
39.     void Update () {
40.        
41.     }
42. }

 

You need to add an script with OnCollisionEnter to your recently created component. For example:

• Move the OnCollisionEnter method of your example to an independent script named "MyCollisionDetector".
• Add this line to the code where you create the object:
  cube.AddComponent<MyCollisionDetector>();

Now the OnCollisionEnter method in MyCollisionDetector will be invoked whenever the newly created cube detects a collision.

However, as for your code, you should have other things in mind as well:

• The primitive cube already includes a collider, which will be the responsible of detecting the collisions. You're also adding a trigger, but this one won't raise collisions. Use OnTriggerEnter instead for detecting the interactions with the trigger.
• As your cube is kinematic, it won't raise collision events unless you configure the parameter at Project Settings > Physics > Contact Pairs Mode. I'd configure it to "Enable All Contact Pairs" to ensure it always work as expected.
• The correct method to move a kinematic rigidbody is calling rigidbody.MovePosition and rigidbody.MoveRotation every FixedUpdate.

Hope this helps!