Question about 2D alternative of mesh collider?

Hi community, sorry for my bad English ^).
I have some trouble with collider generating.

When I generated 3D mesh, I use MeshCollider for collision detection. That the MeshCollider takes the shape of visual mesh use this code like this:

meshCollider.sharedMesh = null;
meshCollider.sharedMesh = visualMesh;
and can take mesh like this (it is one Mesh and MeshCollider):



But MeshCollider not working with 2D colliders. I tried to use the PolygonCollider and there was problem - PolygonCollider joins all points and it turns out the wrong form.

How to create 2D Mesh Collider as in the picture ?

 

Use a PolygonCollider2D. It can have multiple separate paths; see the docs (specifically SetPath).

--Eric

 

Are there any code examples of how to generate a PolygonCollider2D programmatically?

 

https://docs.unity3d.com/ScriptReference/PolygonCollider2D.SetPath.html
This is all official docs what I found. Where can I read more information about separated path of a Polygon Collider ?

 

Use .pathCount to set the number of paths, and then call SetPath as many times as needed with the appropriate index value and Vector2[] array each time.

--Eric

 

Thank's Eric, I'll try it.

 

New Question:
I have Vector2[] array with all points of mesh shape. How can I find the correct index what I need and create new path?

Official documentation is very poor, Is there a more detailed documentation with code examples, how use this, or other source ?

 

That's not what you want; you need multiple Vector2[] arrays. Each Vector2[] array should be a separate shape. For the image you posted at the top of this thread, for example, you would need three Vector2[] arrays.

SetPath is dead simple...it just takes an index, and a Vector2[] array. The Vector2[] array is a list of consecutive points in the collider, and that's all there is to it. If you have just one path, then the index would be 0.

Code (javascript):

1. var points = [Vector2(0, .5), Vector2(.5, 0), Vector2(0, 0)]; // A triangle
2. myCollider.SetPath (0, points);

--Eric

 

That's not what you want; you need multiple Vector2[] arrays. Each Vector2[] array should be a separate shape. For the image you posted at the top of this thread, for example, you would need three Vector2[] arrays.

Ok. For my example (sorry, I cant find bbcode for formating the script code):
I created simple class instead multiple Arrays with Vector2 array.

using UnityEngine;
using System.Collections;
using System;

[Serializable]
public class MeshPoints {

[SerializeField]
public Vector2[] points;
}

In Mesh class I created List of this class type:
public List<MeshPoints> points = new List<MeshPoints> (); //my points Arrays

In each MeshPoint add 4 points (that will be part of Polygon Collider).
Then I touch all my MeshPoints list:

for (int p = 0; p < points.Count; p++) {
meshCollider.SetPath(0, points[p].points);
}

and take this (I create 2 quad): First quad - no collider, last quad - has collider. If I created more quad - take same, the last quad has collider, others do not.