I create a mesh in code, but it's not visible

I have a method which creates a GameObject. It actually creates an object, you can select it in the hierarchy, but you can't actually see it in game, like it has no material.

Here's the method:

Code (CSharp):

1.     void test()
2.     {
3.         float length = 0.7f;
4.         GameObject temp = new GameObject();
5.         Mesh mesh = new Mesh();
6.         Material mat = new Material(Shader.Find("Unlit/Color"));
7.  
8.         var vertices = new Vector3[4]
9.         {
10.             new Vector3(0, 0, 0),
11.             new Vector3(length, 0, 0),
12.             new Vector3(0, length, 0),
13.             new Vector3(length, length, 0)
14.         };
15.  
16.         mesh.vertices = vertices;
17.         mat.color = Color.magenta;
18.  
19.         temp.AddComponent<MeshFilter>();
20.         temp.AddComponent<MeshRenderer>();
21.         temp.GetComponent<MeshFilter>().mesh = mesh;
22.         temp.GetComponent<Renderer>().material = mat;
23.         temp.GetComponent<Renderer>().enabled = true;
24.         Instantiate(temp, new Vector2(1, 1), Quaternion.identity);
25.     }

Maybe someone could help me out?

 

You forgot to add the triangles.

Code (csharp):

1.  
2. mesh.triangles = new int[] { 0, 1, 2, 2, 1, 3 };
3.  

(Which you should do after assigning the vertices.)

 

Still no bueno. The square is not pink as it should be. Maybe something's wrong with the material?

 

I don't know. How does it look now?

 

Screenshots are very helpful for mesh issues.