unity 加載obj文件
大家都知道unity支持fbx，obj等等模型，但是動態加載除了resources加載之外還有打包成ab（assetbundle，以下統稱ab）包用於加載。
但是可能有些同學會有這樣的需求：在加載的時候，拿到了數據，然後轉換爲obj的格式存儲在了一個地方，尤其是移動端，resources等路徑都是隻讀的，所以只能存在sd卡中或者手機內存中，這樣我們如何將這個模型加載到手機設備中顯現出來就面臨着一定的麻煩，所以就有了下面這個以數據轉換的方式~~~
加載的過程可能沒有ab包或者resources加載等順暢（目前還沒有考慮性能方面，如果有這方面的研究的大家可以一起交流~~~）
也可以初步的解決一些問題，如果大家有什麼更好的辦法或者方法請聯繫本人~~~~
下面貼出源碼，這裏用到的方法是，讀取頂點和uv等等數據點，去組合。這個方法不是我寫的，我只是對這個方法做了一些改變使之更適合我來使用~~~~~.
有個方法LoadFile，是用來將讀取到的數據分類存儲到uv集合和頂點集合等中的。
ReadLine這個 方法是組合後的方法形成mesh網格的重要過程。
然後在主函數裏面，是對材質等等的賦值，mesh拿到後，給一個空物體增加meshfilter組件，meshrender組件，material等等，大家可以根據命名看一下，相對簡單一些，就不做過多解釋了，如果有問題我們大家一塊研究。
using UnityEngine;
using System.Collections;
using System.IO;
using System.Collections.Generic;
using System.Globalization;
using UnityEngine.Networking;
using System;
public class LoadMesh : MonoBehaviour
{
public GameObject Loadobj;
private Action<GameObject> creatMeshBack;
Mesh _myMesh;
Vector3[] _vertexArray;
ArrayList _vertexArrayList = new ArrayList();
Vector3[] _normalArray;
ArrayList _normalArrayList = new ArrayList();
Vector2[] _uvArray;
ArrayList _uvArrayList = new ArrayList();
int[] _triangleArray;
ArrayList _facesVertNormUV = new ArrayList();
private void Start()
{
StartCoroutine(SomeFunction(Application.streamingAssetsPath+ "/arrow.obj",
Application.streamingAssetsPath + "/arrow.tga",
_CreatMeshBack));
}
/// <summary>
/// 回掉函數
/// </summary>
/// <param name="obj">加載到的obj在場景中顯示的物體</param>
private void _CreatMeshBack(GameObject obj)
{
Loadobj = obj;
}
internal class PlacesByIndex
{
public PlacesByIndex(int index)
{
_index = index;
}
public int _index;
public ArrayList _places = new ArrayList();
}
void initArrayLists()
{
_uvArrayList = new ArrayList();
_normalArrayList = new ArrayList();
_vertexArrayList = new ArrayList();
_facesVertNormUV = new ArrayList();
}
/// <summary>
/// 加載obj
/// </summary>
/// <param name="ObjPath">mesh</param>
/// <param name="_texturepath">texture</param>
/// <returns></returns>
public IEnumerator SomeFunction(string ObjPath, string _texturepath, Action<GameObject> act)
{
if (File.Exists(ObjPath) && File.Exists(_texturepath))
{
creatMeshBack = act;
GameObject obj_gameobject = new GameObject();
obj_gameobject.name = "objload";
initArrayLists();
if (_myMesh != null)
_myMesh.Clear();
_myMesh = new Mesh();
_myMesh.name = "objload";
Debug.Log(ObjPath);
//更具地址加載模型
UnityWebRequest uwr = UnityWebRequest.Get("file://" + ObjPath);
yield return uwr.Send();
if (uwr.isDone && string.IsNullOrEmpty(uwr.error))
{
string s = uwr.downloadHandler.text;
s = s.Replace(" ", " ");
s = s.Replace(" ", " ");
LoadFile(s);
}
else
{
Debug.LogError(uwr.error);
Debug.LogError(uwr.downloadHandler.text);
}
_myMesh.vertices = _vertexArray;
_myMesh.triangles = _triangleArray;
if (_uvArrayList.Count > 0)
_myMesh.uv = _uvArray;
if (_normalArrayList.Count > 0)
_myMesh.normals = _normalArray;
else
_myMesh.RecalculateNormals();
_myMesh.RecalculateBounds();
if ((MeshFilter)obj_gameobject.GetComponent("MeshFilter") == null)
obj_gameobject.AddComponent<MeshFilter>();
MeshFilter temp;
temp = (MeshFilter)obj_gameobject.GetComponent("MeshFilter");
temp.mesh = _myMesh;
var material = new Material(Shader.Find("Diffuse"));
if ((MeshRenderer)obj_gameobject.GetComponent("MeshRenderer") == null)
obj_gameobject.AddComponent<MeshRenderer>();
if (_uvArrayList.Count > 0 && _texturepath != "")
{
//加載貼圖
UnityWebRequest wwwtx = UnityWebRequest.GetTexture("file://" + _texturepath);
yield return wwwtx.Send();
if (wwwtx.isDone && string.IsNullOrEmpty(wwwtx.error))
{
Debug.Log(" @ !the tex has load");
material.mainTexture = ((DownloadHandlerTexture)wwwtx.downloadHandler).texture;
}
else
{
Debug.LogError(" @ ! load file texture +" + _texturepath + " error : " + wwwtx.error);
}
}
MeshRenderer temp2;
temp2 = (MeshRenderer)obj_gameobject.GetComponent("MeshRenderer");
if (_uvArrayList.Count > 0 && _texturepath != "")
{
temp2.material = material;
}
yield return new WaitForFixedUpdate();
creatMeshBack(obj_gameobject);
}
else
{
creatMeshBack(null);
}
}
public void LoadFile(string s)
{
string[] lines = s.Split("\n"[0]);
foreach (string item in lines)
{
ReadLine(item);
}
ArrayList tempArrayList = new ArrayList();
for (int i = 0; i < _facesVertNormUV.Count; ++i)
{
if (_facesVertNormUV[i] != null)
{
PlacesByIndex indextemp = new PlacesByIndex(i);
indextemp._places.Add(i);
for (int j = 0; j < _facesVertNormUV.Count; ++j)
{
if (_facesVertNormUV[j] != null)
{
if (i != j)
{
Vector3 iTemp = (Vector3)_facesVertNormUV[i];
Vector3 jTemp = (Vector3)_facesVertNormUV[j];
if (iTemp.x == jTemp.x && iTemp.y == jTemp.y)
{
indextemp._places.Add(j);
_facesVertNormUV[j] = null;
}
}
}
}
tempArrayList.Add(indextemp);
}
}
_vertexArray = new Vector3[tempArrayList.Count];
_uvArray = new Vector2[tempArrayList.Count];
_normalArray = new Vector3[tempArrayList.Count];
_triangleArray = new int[_facesVertNormUV.Count];
int teller = 0;
foreach (PlacesByIndex item in tempArrayList)
{
foreach (int item2 in item._places)
{
_triangleArray[item2] = teller;
}
Vector3 vTemp = (Vector3)_facesVertNormUV[item._index];
_vertexArray[teller] = (Vector3)_vertexArrayList[(int)vTemp.x - 1];
if (_uvArrayList.Count > 0)
{
Vector3 tVec = (Vector3)_uvArrayList[(int)vTemp.y - 1];
_uvArray[teller] = new Vector2(tVec.x, tVec.y);
}
if (_normalArrayList.Count > 0)
{
_normalArray[teller] = (Vector3)_normalArrayList[(int)vTemp.z - 1];
}
teller++;
}
}
public void ReadLine(string s)
{
char[] charsToTrim = { ' ', '\n', '\t', '\r' };
s = s.TrimEnd(charsToTrim);
string[] words = s.Split(" "[0]);
foreach (string item in words)
item.Trim();
if (words[0] == "v")
_vertexArrayList.Add(new Vector3(System.Convert.ToSingle(words[1], CultureInfo.InvariantCulture), System.Convert.ToSingle(words[2], CultureInfo.InvariantCulture), System.Convert.ToSingle(words[3], CultureInfo.InvariantCulture)));
if (words[0] == "vn")
_normalArrayList.Add(new Vector3(System.Convert.ToSingle(words[1], CultureInfo.InvariantCulture), System.Convert.ToSingle(words[2], CultureInfo.InvariantCulture), System.Convert.ToSingle(words[3], CultureInfo.InvariantCulture)));
if (words[0] == "vt")
_uvArrayList.Add(new Vector3(System.Convert.ToSingle(words[1], CultureInfo.InvariantCulture), System.Convert.ToSingle(words[2], CultureInfo.InvariantCulture)));
if (words[0] == "f")
{
ArrayList temp = new ArrayList();
ArrayList triangleList = new ArrayList();
for (int j = 1; j < words.Length; ++j)
{
Vector3 indexVector = new Vector3(0, 0);
string[] indices = words[j].Split("/"[0]);
indexVector.x = System.Convert.ToInt32(indices[0], CultureInfo.InvariantCulture);
if (indices.Length > 1)
{
if (indices[1] != "")
indexVector.y = System.Convert.ToInt32(indices[1], CultureInfo.InvariantCulture);
}
if (indices.Length > 2)
{
if (indices[2] != "")
indexVector.z = System.Convert.ToInt32(indices[2], CultureInfo.InvariantCulture);
}
temp.Add(indexVector);
}
for (int i = 1; i < temp.Count - 1; ++i)
{
triangleList.Add(temp[0]);
triangleList.Add(temp[i]);
triangleList.Add(temp[i + 1]);
}
foreach (Vector3 item in triangleList)
{
_facesVertNormUV.Add(item);
}
}
}
}