マイクラの土ブロック

NewBehaviourScript.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NewBehaviourScript : MonoBehaviour{

    public Material material;
    List<int> triangles     = new List<int>();
    List<Vector3> vertices  = new List<Vector3>();
    List<Vector2> uv        = new List<Vector2>();

    void Start(){
        Append(new Voxel(0,0,0,0));
        Init(new GameObject());
    }
    void Append(params Voxel[] voxels){
        foreach(Voxel v in voxels){
            foreach(int t in v.triangles) triangles.Add(vertices.Count+t);
            vertices.AddRange(v.vertices);
            uv.AddRange(v.uv);
        }
    }
    void Init(GameObject g){
        var f = g.AddComponent<MeshFilter>();
        var r = g.AddComponent<MeshRenderer>();
        var m = new Mesh(){
            vertices    = vertices.ToArray(),
            uv          = uv.ToArray(),
            triangles   = triangles.ToArray(),
        };
        f.mesh      = m;
        r.material  = material;
        m.RecalculateNormals();
    }
}

public class Voxel{

    static List<int> data   = new List<int>();
    static int[] order      = {6,7,2,3, 2,3,0,1, 0,1,4,5, 6,2,4,0, 7,6,5,4, 3,7,1,5};
    static int slice        = 8;
    static Voxel(){
        for(int i=0;i<order.Length;i+=4){
            data.AddRange(new []{i,i+1,i+2,i+3,i+2,i+1});
        }
    }

    public List<int> triangles      = data;
    public List<Vector3> vertices   = new List<Vector3>();
    public List<Vector2> uv         = new List<Vector2>();
    public Voxel(int x,int y,int z,int type){
        var cube = new Vector3[8];
        var face = new []{0,1,2,1,1,1};
        for(int i=0;i<8;i++){
            cube[i] = new Vector3((i&1)+x,(i>>1&1)+y,(i>>2&1)+z);
        }
        for(int i=0;i<order.Length;i++){
            vertices.Add(cube[order[i]]);
            uv.Add(new Vector2(type+(i&1),slice-(i>>1&1)-face[i>>2])/slice);
        }
    }
}