Unity点选构建Mesh并保存OBJ
发表于2018-06-28
项目中策划可能会有这样的需求，任意挑选某一片区域，表明是有某种用途的。没有特别好的方法前，使用的是用小方格来代替，并最终构建mesh保存下来的方法，这样做程序的就很方便用了。
1、简单shader编写
通过Shader显示我们所编辑的内容
Shader "Custom/BlockShader" ｛
Properties ｛
_MainTex ("Base (RGB)", 2D) = "white" ｛｝
_Size ("Size",Vector) = (64,32,0,0) //在面板上显示长多少格，宽多少格
_Color ("Color", Color) = (0,0,0,0.5)
_RimColor ("Rim Color", Color) = (1,1,0,1)
_RimPower ("Rim Power", Range(0,0.2)) = 0.01
_HitPoint ("Hit Point",Vector) = (0.0,1,0.0,0.5)//鼠标点击点
_SelectColor ("Select Color",Color) = (0,1,0,1)//选中颜色
_HitColor ("Already hit Color", Color) = (0.2,0.8,0.9,0.5)
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SubShader ｛
Tags ｛ "Queue"="Transparent" ｝
CGPROGRAM
#pragma surface surf Lambert alpha
#pragma target 3.0
sampler2D _MainTex;
half4 _Size;
fixed4 _Color;
fixed4 _RimColor;
float _RimPower;
float4 _HitPoint;
fixed4 _SelectColor;
fixed4 _HitColor;
struct Input ｛
float2 uv_MainTex;
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void surf (Input IN, inout SurfaceOutput o) ｛
float2 uv = IN.uv_MainTex;
fixed4 c = _Color;
float radiox = 1.0 / (_Size.x * 2);//每格大小的一半
float radioy = 1.0 / (_Size.y * 2);
float nx = floor(uv.x/(radiox * 2)) * radiox * 2 + radiox;//找到格的中心点
float ny = floor(uv.y/(radioy * 2)) * radioy * 2 + radioy;
fixed4 tc = tex2D (_MainTex, float2(nx,ny) );
if(tc.g > 0.85) //因为选中我设置为了绿色（0,1,0,1）
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c = _HitColor;
//if(uv.x >= nx-radiox && uv.x <nx+ radiox && uv.y >= ny-radioy && uv.y <= ny+radioy)
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// c = _HitColor;
//｝
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if(uv.x >= _HitPoint.x-radiox && uv.x <_HitPoint.x+ radiox && uv.y >= _HitPoint.y-radioy && uv.y <= _HitPoint.y+radioy)
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c = _SelectColor;//选中颜色
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if(fmod(uv.x ,(radiox * 2)) < (radiox * 2) * _RimPower)//边框
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c = _RimColor;
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if(fmod(uv.y ,(radioy * 2)) < (radioy * 2) * _RimPower)
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c = _RimColor;
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o.Albedo = c.rgb;
o.Alpha = 0.5;
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ENDCG
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FallBack "Diffuse"
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下一步，需要每套的脚本控制
2、脚本控制
主要是为了运行时，通过点击生成方格
using System.Collections.Generic;
using UnityEngine;
/**
*
* 用于编辑器美术使用脚本，功能为画地形方块
*
*/
public class TerrianBlockControl : MonoBehaviour
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public int width;
public int height;
public Texture2D texture;
#if UNITY_EDITOR
private Material material;
private MeshRenderer meshRenderer;
private RaycastHit hit;
private float ratioW;
private float ratioH;
private int[,] matrix;
void Start()
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meshRenderer = GetComponent<MeshRenderer>();
material = meshRenderer.material;
texture = new Texture2D(width * 3, height * 3);
material.SetTexture("_MainTex", texture);
ratioW = 1.0f/width;
ratioH = 1.0f/height;
material.SetVector("_Size", new Vector4(width, height, 0, 0));
matrix = new int[width,height];
MatrixInit();
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public void ChangeSize(int x, int y)
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width = x;
height = y;
ratioW = 1.0f / width;
ratioH = 1.0f / height;
matrix = new int[width,height];
MatrixInit();
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public void Update()
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Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit))
｛//算出每个方格的正中心坐标
float x = Mathf.FloorToInt(hit.textureCoord.x/ratioW)*ratioW + ratioW*0.5f;
float y = Mathf.FloorToInt(hit.textureCoord.y / ratioH) * ratioH + ratioH * 0.5f;
material.SetVector("_HitPoint",new Vector4(x,y,0,0));
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if (Input.GetMouseButtonDown(0))
｛//算出所在格子的坐标
int x = Mathf.FloorToInt(hit.textureCoord.x/ratioW) * 3 + 1;
int y = Mathf.FloorToInt(hit.textureCoord.y/ratioH) * 3 + 1;
Color c = texture.GetPixel(x, y);
if (c.g >= 0.9f)
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texture.SetPixel(x, y, Color.black);
matrix[(x - 1) / 3, (y - 1) / 3] = 0;
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else
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texture.SetPixel(x, y, Color.green);
matrix[(x - 1) / 3, (y - 1) / 3] = 1;
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texture.Apply(true);
material.SetTexture("_MainTex",texture);
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void MatrixInit()
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for (int i = 0; i < width; i++)
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for (int j = 0; j < height; j++)
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matrix[i, j] = 0;
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List<rect> rects;
[ContextMenu("Save")]
public GameObject Save()
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rects = new List<rect>();
for (int i = 0; i < width; i++) //合并，把我们已经画好的方格进行合并
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for (int j = 0; j < height; j++)
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if (matrix[i, j] == 1)
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rect r = new rect();
r.dl = new Vector3(i,j,0);
r.dr = new Vector3(i+1,j,0);
r.ul = new Vector3(i,j+1,0);
r.ur = new Vector3(i+1,j+1);
r.length = 1;
matrix[i, j] = 0;
for (int k = i+1; k < width; k++) //在width方向上进行合并
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if (matrix[k, j] == 1)
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r.dr=new Vector3(k+1,j,0);
r.ur = new Vector3(k+1,j+1,0);
matrix[k, j] = 0;
r.length++;
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else
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break;
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for (int k = i-1; k >= 0; k--)
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if (matrix[k, j] == 1)
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r.dl = new Vector3(k,j,0);
r.ul = new Vector3(k,j+1,0);
matrix[k, j] = 0;
r.length++;
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else
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break;
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rects.Add(r);
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for (int i = 0; i < rects.Count; i++) //把合并过的，相邻的且大小相等的再合并
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if (!rects[i].used && rects[i].length != 0)
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for (int j = 0; j < rects.Count; j++)
｛//没有合并过 不是自身
if (!rects[j].used && i != j && rects[j].length != 0)
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if (rects[i].length == rects[j].length)
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if (rects[i].dl.x == rects[j].dl.x)
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if (rects[i].ul.y - rects[j].ul.y == 1)
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rects[i].dl = rects[j].dl;
rects[i].dr = rects[j].dr;
rects[i].used = true;
rects[j].length = 0;
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if (rects[i].ul.y - rects[j].ul.y == -1)
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rects[i].ul = rects[j].ul;
rects[i].ur = rects[j].ur;
rects[i].used = true;
rects[j].length = 0;
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if (rects[i].length != 0 && rects[i].ul.y - rects[i].dl.y == 1)
rects[i].used = true;
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return creat(rects);
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class rect
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public Vector3 dl;
public Vector3 dr;
public Vector3 ul;
public Vector3 ur;
public int length;
public bool used;
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//创建mesh
GameObject creat(List<rect> rects_Old )
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List<rect> rects = new List<rect>();
foreach (var rr in rects_Old)
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if(rr.used)
rects.Add(rr);
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GameObject mp = GameObject.Find("MaskParent");
if(mp == null)
mp = new GameObject("MaskParent");
mp.transform.position = Vector3.zero;
GameObject go = new GameObject(transform.name);
go.transform.parent = mp.transform;
go.transform.localPosition = Vector3.zero;
MeshFilter mf = go.AddComponent<MeshFilter>();
MeshRenderer mr = go.AddComponent<MeshRenderer>();
mr.material = new Material(Shader.Find("Diffuse"));
Mesh mesh = new Mesh();
Vector3[] vectices = new Vector3[rects.Count*4];
int[] trangles = new int[rects.Count * 6];
Vector3 startPos = transform.position;
float scalex = transform.localScale.x;
float scaley = transform.localScale.y;
startPos.x -= scalex * 0.5f;
startPos.z -= scaley * 0.5f;
int len = 0;
for (int i = 0; i < rects.Count; i++)
｛//添加mesh的Vectices
rect r = rects[i];
Vector3 dl = new Vector3(startPos.x + ratioW * r.dl.x * scalex, startPos.z + ratioH * r.dl.y * scaley, 0);
Vector3 dr = new Vector3(startPos.x + ratioW * r.dr.x * scalex, startPos.z + ratioH * r.dr.y * scaley, 0);
Vector3 ul = new Vector3(startPos.x + ratioW * r.ul.x * scalex, startPos.z + ratioH * r.ul.y * scaley, 0);
Vector3 ur = new Vector3(startPos.x + ratioW * r.ur.x * scalex, startPos.z + ratioH * r.ur.y * scaley, 0);
vectices[i*4] = dl;
vectices[i * 4 + 1] = dr;
vectices[i * 4 + 2] = ul;
vectices[i * 4 + 3] = ur;//根据上面的点顺时针画三角形
trangles[i*6] = i*4;
trangles[i * 6 + 1] = i * 4 +2;
trangles[i * 6 + 2] = i * 4 +1;
trangles[i * 6 + 3] = i * 4 +1;
trangles[i * 6 + 4] = i * 4 +2;
trangles[i * 6 + 5] = i * 4 +3;
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mesh.vertices = vectices;
mesh.triangles = trangles;
mesh.RecalculateNormals();
mesh.RecalculateBounds();
mf.mesh = mesh;
return go;
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#endif
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根据以上两步能得到画好的mesh图形，还需要保存。
3、保存自创Mesh
可能会有些麻烦，参考这篇文章才成功导出成OBJ文件，在unity中生成FBX。
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UnityEngine;
public class ObjExporter
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//
// Static Methods
//
public static void MeshToFile(MeshFilter mf, string filename, float scale)
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using (StreamWriter streamWriter = new StreamWriter(filename))
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streamWriter.Write(ObjExporter.MeshToString(mf, scale));
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public static string MeshToString(MeshFilter mf, float scale)
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Mesh mesh = mf.mesh;
Material[] sharedMaterials = mf.GetComponent<Renderer>().sharedMaterials;
Vector2 textureOffset = mf.GetComponent<Renderer>().material.GetTextureOffset("_MainTex");
Vector2 textureScale = mf.GetComponent<Renderer>().material.GetTextureScale("_MainTex");
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append("mtllib design.mtl").Append("\n");
stringBuilder.Append("g ").Append(mf.name).Append("\n");
Vector3[] vertices = mesh.vertices;
for (int i = 0; i < vertices.Length; i++)
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Vector3 vector = vertices[i];
stringBuilder.Append(string.Format("v ｛0｝ ｛1｝ ｛2｝\n", vector.x * scale, vector.z * scale, vector.y * scale));
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stringBuilder.Append("\n");
Dictionary<int, int> dictionary = new Dictionary<int, int>();
if (mesh.subMeshCount > 1)
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int[] triangles = mesh.GetTriangles(1);
for (int j = 0; j < triangles.Length; j += 3)
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if (!dictionary.ContainsKey(triangles[j]))
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dictionary.Add(triangles[j], 1);
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if (!dictionary.ContainsKey(triangles[j + 1]))
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dictionary.Add(triangles[j + 1], 1);
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if (!dictionary.ContainsKey(triangles[j + 2]))
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dictionary.Add(triangles[j + 2], 1);
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for (int num = 0; num != mesh.uv.Length; num++)
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Vector2 vector2 = Vector2.Scale(mesh.uv[num], textureScale) + textureOffset;
if (dictionary.ContainsKey(num))
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stringBuilder.Append(string.Format("vt ｛0｝ ｛1｝\n", mesh.uv[num].x, mesh.uv[num].y));
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else
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stringBuilder.Append(string.Format("vt ｛0｝ ｛1｝\n", vector2.x, vector2.y));
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for (int k = 0; k < mesh.subMeshCount; k++)
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stringBuilder.Append("\n");
if (k == 0)
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stringBuilder.Append("usemtl ").Append("Material_design").Append("\n");
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if (k == 1)
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stringBuilder.Append("usemtl ").Append("Material_logo").Append("\n");
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int[] triangles2 = mesh.GetTriangles(k);
for (int l = 0; l < triangles2.Length; l += 3)
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stringBuilder.Append(string.Format("f ｛0｝/｛0｝ ｛1｝/｛1｝ ｛2｝/｛2｝\n", triangles2[l] + 1, triangles2[l + 1] + 1, triangles2[l + 2] + 1));
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return stringBuilder.ToString();
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