obj模型的显示

obj文件格式

# 3ds Max Wavefront OBJ Exporter v0.97b - (c)2007 guruware
# 创建的文件:04.06.2012 11:16:43

mtllib aa.mtl

#
# object Box001
#

v  -14.0142 -4.2691 13.9796
v  13.5541 -4.2691 13.9796
v  -14.0142 -4.2691 -13.5887
v  13.5541 -4.2691 -13.5887
v  -14.0142 23.2992 13.9796
v  13.5541 23.2992 13.9796
v  -14.0142 23.2992 -13.5887
v  13.5541 23.2992 -13.5887
# 8 vertices

vt 1.0000 0.0000 0.0000
vt 1.0000 1.0000 0.0000
vt 0.0000 1.0000 0.0000
vt 0.0000 0.0000 0.0000
# 4 texture coords

g Box001
usemtl Material__25
f 1/1 3/2 4/3
f 4/3 2/4 1/1
f 5/4 6/1 8/2
f 8/2 7/3 5/4
f 1/4 2/1 6/2
f 6/2 5/3 1/4
f 2/4 4/1 8/2
f 8/2 6/3 2/4
f 4/4 3/1 7/2
f 7/2 8/3 4/4
f 3/4 1/1 5/2
f 5/2 7/3 3/4
# 12 faces

上面的数据都不可直接使用,

 v 代表顶点  vt代表贴图 两个都可以当作哈希表,

f /前面为索引  /后面为贴图,

顶点和贴图根据f参数查找前面的表生成一份数据,

索引为f的个数.文件解析类

package
{
	import flash.display3D.Context3D;
	import flash.display3D.IndexBuffer3D;
	import flash.display3D.VertexBuffer3D;
	import flash.utils.ByteArray;
	
	/**
	 *  @author:Gaara
	 *  2012-6-2
	 *   
	 * Obj文件解析类
	 **/
	public class ObjParser
	{
		/** 换行 分隔符 **/
		private var NEWLINE:String = "\r\n";
		
		/** 参数 分隔符 **/
		private var SEPARATION:String = " ";
		
		/** 顶点标志 **/
		private var VERTEX:String = "v";
		
		/** 贴图标志 **/
		private var TEXTURE:String = "vt";
		
		/** 面标志 **/
		private var FACE:String = "f";
		
		private var context3D:Context3D;
		
		/** 顶点数据 **/
		private var vertices:Vector.<Number>;
		
		/** 贴图基础数据 **/
		private var texturesBase:Vector.<Number>;
		
		/** 索引数据 **/
		private var indexs:Vector.<uint>;
		
		/** 贴图数据数据 **/
		private var textures:Vector.<int>;
		
		
		/** 返回的数据 **/
		private var vertexBuff3D:VertexBuffer3D;
		private var indexBuff3D:IndexBuffer3D;
		private var uvBuff3D:VertexBuffer3D;
		
		public function ObjParser(objClass:Class,context3D:Context3D)
		{
			this.context3D = context3D;
			
			var obj:ByteArray = new objClass;
			var contentStr:String = obj.readUTFBytes(obj.length);
			
			vertices = new Vector.<Number>;
			texturesBase = new Vector.<Number>;
			indexs = new Vector.<uint>;
			textures = new Vector.<int>;
			
			var conArr:Array = contentStr.split(NEWLINE);
			handleStrArr(conArr);
		}
		
		/**
		 *  功能:处理字符串数组
		 *  参数:
		 **/
		private function handleStrArr(strArr:Array):void
		{
			for each (var str:String in strArr) 
			{
				var preStr:String = str.split(" ")[0];
				if(preStr == VERTEX){
					vertexTexturesHandle(str,vertices);
				}
				else if(preStr == TEXTURE){
					vertexTexturesHandle(str,texturesBase);
				}
				else if(preStr == FACE){
					faceHandle(str);
				}
			}
			trace("obj解析完成");
		}
		
		/**
		 *  功能:添加顶点函数
		 *  参数:
		 **/
		private function vertexTexturesHandle(content:String,vec:Vector.<Number>):void
		{
			var strArr:Array = content.split(SEPARATION);
			for each (var str:String in strArr) 
			{
				if(str != VERTEX && str != TEXTURE && str !=""){
					vec.push(Number(str));
				}
			}
			
		}
		
		/**
		 *  功能:添加三角形数据函数
		 *  参数:
		 **/
		private function faceHandle(content:String):void
		{
			var strArr:Array = content.split(SEPARATION);
			var tempArr:Array;
			for each (var str:String in strArr) 
			{
				if(str != FACE && str !=""){
					tempArr = str.split("\/");
					indexs.push(tempArr[0]-1);
					textures.push(tempArr[1]-1);
				}
			}
		}
		
		/**
		 *  功能:返回顶点数据
		 *  参数:
		 **/
		public function get positionsBuffer():VertexBuffer3D
		{
			if(vertexBuff3D != null){
				return vertexBuff3D;
			}
			
			var positionBuffer:Vector.<Number> = new Vector.<Number>;
			for each (var i:int in indexs) 
			{
				positionBuffer.push(vertices[i*3],vertices[i*3+1],vertices[i*3+2]);
			}
			
			var vertexCount:uint = positionBuffer.length/3;
			vertexBuff3D = context3D.createVertexBuffer(vertexCount,3);
			vertexBuff3D.uploadFromVector(positionBuffer,0,vertexCount);
			return vertexBuff3D;
		}
		
		/**
		 *  功能:索引
		 *  参数:
		 **/
		public function get indexBuffer():IndexBuffer3D
		{
			if(indexBuff3D){
				return indexBuff3D;
			}
			
			var indexBufferVec:Vector.<uint> = new Vector.<uint>;
			for (var i:int = 0; i < indexs.length; i++) 
			{
				indexBufferVec.push(i);
			}
			
			indexBuff3D = context3D.createIndexBuffer(indexBufferVec.length);
			indexBuff3D.uploadFromVector(indexBufferVec,0,indexBufferVec.length);
			return indexBuff3D;
		}
		
		/**
		 *  功能:贴图数据
		 *  参数:
		 **/
		public function get uvBuffer():VertexBuffer3D
		{
			if(uvBuff3D){
				return uvBuff3D;
			}
			
			
			var uvBufferVec:Vector.<Number> = new Vector.<Number>;
			
			for each (var i:int in textures) 
			{
				uvBufferVec.push(1-texturesBase[i*3],1-texturesBase[i*3+1]);
			}
			var uvsCount:uint = uvBufferVec.length/2;
			
			uvBuff3D = context3D.createVertexBuffer(uvsCount,2);
			uvBuff3D.uploadFromVector(uvBufferVec,0,uvsCount);
			return uvBuff3D;
		}
	}
}