Generated mesh doesn't get the proper MeshCollider.sharedMesh

So I learnt you can generate a mesh in Unity, pretty cool! The only problem I have is when I try to add a MeshCollider. As you can see in the screenshot below, the collider is added but it only appears to draw the surface between the peaks of the mesh. Any ideas on how to address that? Am I doing something wrong during generation?


I use this to attach the collider

Code (csharp):

1.  
2.         meshCollider = root.AddComponent<MeshCollider> ();
3.         meshCollider.convex = true;
4.         meshCollider.sharedMesh = mesh;

 

Hello,

Usually adding a MeshCollider works well. You don't need to explicitly specify a mesh for the collider it will create it automatically. Remove the last line it may works.

 

Thanks. Tried it but it didn't change anything. Here's the source:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class GenerateTerrain : MonoBehaviour
5. {
6.     public Vector3 size = new Vector3(20f, 20f, 2f);
7.     public float NoiseSize = 10.0f;
8.  
9.     private float _randH;
10.     private float _randN;
11.  
12.     private GameObject terrain;
13.     private Mesh mesh;
14.     private MeshCollider meshCollider;
15.  
16.     // create the objects and add components
17.     void Start() {
18.         terrain = new GameObject("test");
19.         terrain.transform.position = Vector3.zero;
20.         terrain.transform.parent = transform;
21.         mesh = terrain.AddComponent<MeshFilter> ().mesh;
22.         terrain.AddComponent<MeshRenderer> ().material.color = Color.white;
23.         meshCollider = terrain.AddComponent<MeshCollider> ();
24.         meshCollider.convex = true;
25. //        meshCollider.sharedMesh = mesh;
26. //        Rigidbody rb = root.AddComponent<Rigidbody> ();
27. //        rb.useGravity = false;
28. //        rb.isKinematic = true;
29.  
30.         _randH = size.z;//*(0.5f + Random.value);
31.         _randN = NoiseSize;//*(0.5f + Random.value);
32.     }
33.  
34.     public float PerlinNoise(float x, float y) {
35.         return _randH*Mathf.PerlinNoise(x/_randN, y/_randN);
36.     }
37.  
38.     void Update(){
39.         Generate ();
40.     }
41.  
42.     // generate Perlin-mesh
43.     void Generate(){
44.         var vertices = new Vector3[(int) (size.x*size.y)];
45.         var uv = new Vector2[(int) (size.x*size.y)];
46.         var tangents = new Vector4[(int) (size.x*size.y)];
47.  
48.         for (int y = 0; y < size.y; y++){
49.             for (int x = 0; x < size.x; x++) {
50.                 float z = PerlinNoise (Time.time*1.13f + x, 1000+Time.time*0.98f + x);
51.                 vertices[(int) (y*size.x + x)] = new Vector3 (x, y, z);
52.                 uv[(int) (y*size.x + x)] = new Vector2(x, y);
53.                 tangents[(int) (y*size.x + x)] = new Vector4(1f, 0f, 0f, -1.0f);
54.             }
55.         }
56.  
57.         // Build triangle indices: 3 indices into vertex array for each triangle
58.         var triangles = new int[(int) ((size.y - 1) * (size.x - 1) * 6)];
59.         int index = 0;
60.         for (int y=0; y < size.y-1; y++){
61.             for (int x=0; x < size.x-1; x++) {
62.                 // For each grid cell output two triangles
63.                 triangles[index++] = (int) (y     * size.x) + x;
64.                 triangles[index++] = (int) ((y+1) * size.x) + x;
65.                 triangles[index++] = (int) (y     * size.x) + x + 1;
66.  
67.                 triangles[index++] = (int) ((y+1) * size.x) + x;
68.                 triangles[index++] = (int) ((y+1) * size.x) + x + 1;
69.                 triangles[index++] = (int) (y     * size.x) + x + 1;
70.             }
71.         }
72.  
73.         // And assign them to the mesh
74.         mesh.vertices = vertices;
75.         mesh.uv = uv;
76.         mesh.triangles = triangles;
77.  
78. //        Auto-calculate vertex normals from the mesh
79.         mesh.RecalculateNormals();
80.  
81. //        Assign tangents after recalculating normals
82.         mesh.tangents = tangents;
83.     }
84.  
85. }
86.