How to add collider to a Line Renderer

A while ago i asked for help to make incomplete rings, and i have succeeded. Since then i've been doing some work and now i have 1 more problem i can't add a collider to it. I've added edge collider to a ring but it's in the center and i can't figure out how to move it to the inner edge or even better a polygon collider around it whole. Here's what i ended up with

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. [RequireComponent(typeof(LineRenderer))]
7. public class RingCreation : MonoBehaviour {
8.  
9.     public int segments;
10.     public float xradius;
11.     public float yradius;
12.     public int gap;
13.     LineRenderer line;
14.    
15.     EdgeCollider2D edge;
16.     CapsuleCollider2D capsule;
17.     List<Vector2> colliderPoints = new List<Vector2>();
18.  
19.     private void Awake()
20.     {
21.         line = GetComponent<LineRenderer>();
22.         line.SetVertexCount(segments + 1 - (segments / gap));
23.         line.useWorldSpace = false;
24.         CreatePoints();
25.         addCollider();
26.     }
27.  
28.     void CreatePoints()
29.     {
30.         float x;
31.         float y;
32.         float z = 0f;
33.  
34.         float angle = 0f;
35.  
36.         for (int i = 0; i < (segments + 1) - (segments / gap); i++)
37.         {
38.             x = Mathf.Sin(Mathf.Deg2Rad * angle) * xradius;
39.             y = Mathf.Cos(Mathf.Deg2Rad * angle) * yradius;
40.  
41.             line.SetPosition(i, new Vector3(x, y, z));
42.  
43.             Vector3 col = new Vector3(x, y, z);
44.             colliderPoints.Add(col);
45.  
46.             angle += (360f / segments);
47.         }
48.     }
49.  
50.     void addCollider()
51.     {
52.         List<Vector2> colliderPoints2 = new List<Vector2>();
53.  
54.         for (int i = 0; i < colliderPoints.Count; i++)
55.         {
56.             colliderPoints2.Add(new Vector3(colliderPoints[i].x, colliderPoints[i].y, 0f));
57.         }
58.  
59.         for (int i = colliderPoints.Count - 1; i > 0; i--)
60.         {
61.             colliderPoints2.Add(new Vector3(colliderPoints[i].x, colliderPoints[i].y, 0f));
62.         }
63.  
64.         edge = line.gameObject.AddComponent<EdgeCollider2D>();
65.         edge.points = colliderPoints2.ToArray();
66.     }
67. }
68.  

 

You can use PolygonCollider2D and use LineRenderer half width to add points.

Here is an example:

Code (CSharp):

1. float halfWidth = line.startWidth / 2f;
2. Vector2 rightPoint = colliderPoints[i];
3. Vector2 leftPoint = colliderPoints[i];
4. rightPoint.x -= halfWidth;
5. leftPoint.x += halfWidth;
6. colliderPoints2.Add(rightPoint);
7. colliderPoints2.Add(leftPoint));

Thanks.

 

Since Unity 2018.2, you can now use the public method BakeMesh of LineRenderer. This will give you the mesh along the LineRenderer with all the segments. You can then use this mesh with a mesh collider in order to detect Collisions and Raycasts.

Code (CSharp):

1.  LineRenderer lineRenderer = line.GetComponent<LineRenderer>();
2. MeshCollider meshCollider = line.AddComponent<MeshCollider>();
3.  
4. Mesh mesh = new Mesh();
5. lineRenderer.BakeMesh(mesh, true);
6. meshCollider.sharedMesh = mesh;

I tested it and it worked on my project. Let me know what you think about it and if it helps you !

 

I tried the code that "bertrand_arnaud" provided, but unity gives error that says

argumentnullexception: value cannot be null. parameter name: camera unityengine.linerenderer.bakemesh (unityengine.mesh mesh, system.boolean usetransform)

How can I solve the error?

 

Take a look at the documentation: https://docs.unity3d.com/ScriptReference/LineRenderer.BakeMesh.html

One of the overloads takes a Camera parameter. That's what your error is talking about. Try passing in your main camera as a second parameter, or make sure you have a camera tagged MainCamera available in your scene.

 

ı want to add collider to my line renderer but i did not understand your post. How ı will create mesh in line

 

I do see the mesh from my Line Renderer using BakeMesh, but he's far away, living his dream in his own dimension lol. I guess I must fix something related to WorldSpace Vs LocalSpace (my LineRenderer uses WorldSpace). If anyone has any input on that one, I'm down! Peace out

 

if you add

Code (CSharp):

1.        
2.  //beware this makes lineRenderer using local space
3.  myLineRenderer.useWorldSpace = false;
4.  

then it should work

 

to be more complete, here is a script(Liner.cs) that should be able to quickly test out adding collider on lineRenderer:

Code (CSharp):

1.  
2. /*
3. Liner.cs
4. for this to work, do the following steps:
5. 1  Make sure "Main Camera" exists, and its position and rotation are 0s for all xyz directions
6. 2. Create a scripts with filename "Liner.cs"
7. 3. Copy this whole code into the Liner script  (the script is using the new input system, if you are on old one , rmb to change two lines( code below have details ))
8. 4. Create an Empty GameObject in your scene, and add the Liner script as a component
9. 5. click Play, you should be able to see a red line, click on it, will change color, then hooray, collider works
10. */
11.  
12. using System.Collections;
13. using System.Collections.Generic;
14. using UnityEngine;
15. using UnityEngine.InputSystem;
16.  
17. public class Liner : MonoBehaviour
18. {
19.     LineRenderer lr;
20.     Color[] colors = { Color.red, Color.black };
21.     int curColor = 0;
22.     void Start()
23.     {
24.         lr = this.gameObject.AddComponent<LineRenderer>();
25.         lr.material = new Material(Shader.Find("Sprites/Default"));
26.         lr.material.color = colors[curColor];
27.         lr.startWidth = 1f;
28.         lr.endWidth = 1f;
29.         lr.positionCount = 2;
30.  
31.         Vector3[] poses = new Vector3[2];
32.         poses[0] = new Vector3(0, 10f, 100f);
33.         poses[1] = new Vector3(5f, -3f, -4f);
34.         lr.SetPositions(poses);
35.  
36.  
37.         // making a meshcolllider and attach to the lineRenderer
38.  
39.         //beware this makes lineRenderer using local space
40.         lr.useWorldSpace = false;
41.  
42.         MeshCollider meshCollider = this.gameObject.AddComponent<MeshCollider>();
43.         Mesh mesh = new Mesh();
44.         lr.BakeMesh(mesh, Camera.main, false);
45.         meshCollider.sharedMesh = mesh;
46.  
47.  
48.     }
49.     void Update()
50.     {
51.         // when you click on the line, the line color should change between red and black
52.  
53.         // be aware that I am using the new input system
54.         // if using the old input system, i think you replace the the next line with "if(Input.GetMouseButtonDown(0))"
55.         if (Mouse.current.leftButton.wasPressedThisFrame)
56.         {
57.             // if using the old input system, i think you replace the the next line with "Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);"
58.             Ray ray = Camera.main.ScreenPointToRay(Mouse.current.position.ReadValue());
59.             RaycastHit hitData_for_the_ray;
60.             if (Physics.Raycast(ray, out hitData_for_the_ray))
61.             {
62.                 GameObject theGameObjectHitByRay = hitData_for_the_ray.collider.gameObject;
63.                 {
64.                     if (theGameObjectHitByRay == this.gameObject)
65.                     {
66.                         curColor = (curColor + 1) % 2;
67.                         lr.material.color = colors[curColor];
68.                     }
69.                 }
70.             }
71.         }
72.     }
73. }
74.