unity点选构建Mesh并保存OBJ

最近有一份需求，就是让策划任意选择可一片区域，表明是有某种用途的。埋头写了两头，试了三四种方法，最终不得已用小方格来代替，并最终构建mesh保存下来，这样做程序的就很方便用了。我们的目标就是没有蛀牙oh，应该是累死别人，轻松自己！！！

1，简单shader编写

首先应该搞一个简单的Shader来显示我们的所编辑的内容

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)}SubShader {Tags { "Queue"="Transparent" }CGPROGRAM#pragma surface surf Lambert alpha#pragma target 3.0sampler2D _MainTex;half4 _Size;fixed4 _Color;fixed4 _RimColor;float _RimPower;float4 _HitPoint;fixed4 _SelectColor;fixed4 _HitColor;struct Input {float2 uv_MainTex;};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）{c = _HitColor;//if(uv.x >= nx-radiox && uv.x <nx+ radiox && uv.y >= ny-radioy && uv.y <= ny+radioy)//{ //c = _HitColor;//}}if(uv.x >= _HitPoint.x-radiox && uv.x <_HitPoint.x+ radiox && uv.y >= _HitPoint.y-radioy && uv.y <= _HitPoint.y+radioy){ c = _SelectColor;//选中颜色}if(fmod(uv.x ,(radiox * 2)) < (radiox * 2) * _RimPower)//边框{c = _RimColor;}if(fmod(uv.y ,(radioy * 2)) < (radioy * 2) * _RimPower){c = _RimColor;}o.Albedo = c.rgb;o.Alpha = 0.5;}ENDCG} FallBack "Diffuse"}

我知道，以上写的很粗糙。。。但是，谁让我是pc上用的呢，谁还管效率是毛线

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{    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()    {        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();    }    public void ChangeSize(int x, int y)    {        width = x;        height = y;        ratioW = 1.0f / width;        ratioH = 1.0f / height;        matrix = new int[width,height];        MatrixInit();    }    public void Update()    {        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));        }        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)            {                texture.SetPixel(x, y, Color.black);                matrix[(x - 1) / 3, (y - 1) / 3] = 0;            }            else            {                texture.SetPixel(x, y, Color.green);                matrix[(x - 1) / 3, (y - 1) / 3] = 1;            }            texture.Apply(true);            material.SetTexture("_MainTex",texture);        }    }    void MatrixInit()    {        for (int i = 0; i < width; i++)        {            for (int j = 0; j < height; j++)            {                matrix[i, j] = 0;            }        }    }    List<rect> rects;    [ContextMenu("Save")]    public GameObject Save()    {        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        {            for (int j = 0; j < height; j++)            {                if (matrix[i, j] == 1)                {                    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                    {                        if (matrix[k, j] == 1)                        {                            r.dr=new Vector3(k+1,j,0);                            r.ur = new Vector3(k+1,j+1,0);                            matrix[k, j] = 0;                            r.length++;                        }                        else                        {                            break;                        }                    }                    for (int k = i-1; k >= 0; k--)                    {                        if (matrix[k, j] == 1)                        {                            r.dl = new Vector3(k,j,0);                            r.ul = new Vector3(k,j+1,0);                            matrix[k, j] = 0;                            r.length++;                        }                        else                        {                            break;                        }                    }                    rects.Add(r);                }            }        }                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        {            if (!rects[i].used && rects[i].length != 0)            {                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)                    {                        if (rects[i].length == rects[j].length)                        {                            if (rects[i].dl.x == rects[j].dl.x)                            {                                if (rects[i].ul.y - rects[j].ul.y == 1)                                {                                    rects[i].dl = rects[j].dl;                                    rects[i].dr = rects[j].dr;                                                                        rects[i].used = true;                                    rects[j].length = 0;                                }                                if (rects[i].ul.y - rects[j].ul.y == -1)                                {                                    rects[i].ul = rects[j].ul;                                    rects[i].ur = rects[j].ur;                                    rects[i].used = true;                                    rects[j].length = 0;                                }                            }                        }                    }                }            }            if (rects[i].length != 0 && rects[i].ul.y - rects[i].dl.y == 1)                rects[i].used = true;        }        return creat(rects);    }    class rect    {        public Vector3 dl;        public Vector3 dr;        public Vector3 ul;        public Vector3 ur;        public int length;        public bool used;    }//创建mesh    GameObject creat(List<rect> rects_Old )    {        List<rect> rects = new List<rect>();        foreach (var rr in rects_Old)        {            if(rr.used)                rects.Add(rr);        }        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;        }        mesh.vertices = vectices;        mesh.triangles = trangles;        mesh.RecalculateNormals();        mesh.RecalculateBounds();        mf.mesh = mesh;        return go;    }#endif}

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

这个很蛋疼，因为在运行状态下，原以为保存成预制没事，然后停止后还是尘归尘土归土。。。最后找了很久，感谢这位的博客帮助，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{    //    // Static Methods    //    public static void MeshToFile(MeshFilter mf, string filename, float scale)    {        using (StreamWriter streamWriter = new StreamWriter(filename))        {            streamWriter.Write(ObjExporter.MeshToString(mf, scale));        }    }    public static string MeshToString(MeshFilter mf, float scale)    {        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++)        {            Vector3 vector = vertices[i];            stringBuilder.Append(string.Format("v {0} {1} {2}\n", vector.x * scale, vector.z * scale, vector.y * scale));        }        stringBuilder.Append("\n");        Dictionary<int, int> dictionary = new Dictionary<int, int>();        if (mesh.subMeshCount > 1)        {            int[] triangles = mesh.GetTriangles(1);            for (int j = 0; j < triangles.Length; j += 3)            {                if (!dictionary.ContainsKey(triangles[j]))                {                    dictionary.Add(triangles[j], 1);                }                if (!dictionary.ContainsKey(triangles[j + 1]))                {                    dictionary.Add(triangles[j + 1], 1);                }                if (!dictionary.ContainsKey(triangles[j + 2]))                {                    dictionary.Add(triangles[j + 2], 1);                }            }        }        for (int num = 0; num != mesh.uv.Length; num++)        {            Vector2 vector2 = Vector2.Scale(mesh.uv[num], textureScale) + textureOffset;            if (dictionary.ContainsKey(num))            {                stringBuilder.Append(string.Format("vt {0} {1}\n", mesh.uv[num].x, mesh.uv[num].y));            }            else            {                stringBuilder.Append(string.Format("vt {0} {1}\n", vector2.x, vector2.y));            }        }        for (int k = 0; k < mesh.subMeshCount; k++)        {            stringBuilder.Append("\n");            if (k == 0)            {                stringBuilder.Append("usemtl ").Append("Material_design").Append("\n");            }            if (k == 1)            {                stringBuilder.Append("usemtl ").Append("Material_logo").Append("\n");            }            int[] triangles2 = mesh.GetTriangles(k);            for (int l = 0; l < triangles2.Length; l += 3)            {                stringBuilder.Append(string.Format("f {0}/{0} {1}/{1} {2}/{2}\n", triangles2[l] + 1, triangles2[l + 1] + 1, triangles2[l + 2] + 1));            }        }        return stringBuilder.ToString();    }}

懒得传图片了，就这样吧，反正我的可以用了，留个纪念吧。