function RecalculateNormals () : void

Description

Recalculates the normals of the mesh from the triangles and vertices.

After modifying the vertices it is often useful to update the normals to reflect the change. Normals are calculated from all shared vertices. Imported meshes sometimes don't share all vertices. For example a vertex at a uv seam will be split into two vertices. Thus the RecalculateNormals function will create normals that are not smooth at the uv seam. Also note that RecalculateNormals does not generate tangents automatically thus bumpmap shaders will not work with the mesh after calling RecalculateNormals. You can provide your own tangents however.

function Start () {
    var mesh : Mesh = GetComponent(MeshFilter).mesh;
    mesh.RecalculateNormals();
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Start() {
        Mesh mesh = GetComponent<MeshFilter>().mesh;
        mesh.RecalculateNormals();
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Start():
        mesh as Mesh = GetComponent[of MeshFilter]().mesh
        mesh.RecalculateNormals()