ChunkMesh.cs

public class ChunkMesh {

    private List<Vector3> _vertices = new List<Vector3>();
    private List<Vector2> _uvs = new List<Vector2>();
    private List<Vector3> _normals = new List<Vector3>();
    private List<int> _triangles = new List<int>();

    private int _triangleCount = 0;

    public ChunkMesh() {

    }

    public void AddFaceFor(Block block, Vector3 normal) {
        Vector3 worldPosition = (Vector3) block.World;
 
        // Retrieve a generic quad definition given the normal
        Quad quad = Quads.ForNormal(normal);

        // Move the generic quad vertices to their world position
        foreach (Vector3 v in quad.Vertices) {
            _vertices.Add(worldPosition + v);
        }

        // Add all the UVs
        _uvs.AddRange(quad.UVs);

        // Add the normal for each vertex 
        int normals = 4;
        while (normals-- > 0) {
            _normals.Add(quad.Normal);
        }

        // Add the vertex indices that make up the quad
        _triangles.Add(_triangleCount);
        _triangles.Add(_triangleCount + 1);
        _triangles.Add(_triangleCount + 2);
        _triangles.Add(_triangleCount + 2);
        _triangles.Add(_triangleCount + 1);
        _triangles.Add(_triangleCount + 3);

        _triangleCount += 4;
    }

    public Mesh ToMesh() {
        Mesh m = new Mesh();
        m.vertices = _vertices.ToArray();
        m.uv = _uvs.ToArray();
        m.normals = _normals.ToArray();
        m.triangles = _triangles.ToArray();
        return m;
    }
}