//读入顶点索引
void ReadVertexIndices(t3DObject pObject, tChunk pPreviousChunk)
{
int index = 0;
//读入该对象中面的数目
pPreviousChunk.bytesRead += fread(ref pObject.numOfFaces, 2, m_FilePointer);
//分配所有的储存空间，并初始化结构
pObject.pFaces = new tFace[pObject.numOfFaces];
//遍历对象中所有的面
for (int i = 0; i < pObject.numOfFaces; i++)
{
pObject.pFaces[i] = new tFace();
for (int j = 0; j < 4; j++)
{
//读入当前对象的第一个点
pPreviousChunk.bytesRead += fread(ref index, 2, m_FilePointer);
if (j < 3)
{
pObject.pFaces[i].vertIndex[j] = index;
}
}
}
}
//读入对象的材质名称
void ReadObjectMaterial(t3DModel pModel, t3DObject pObject, tChunk pPreviousChunk)
{
String strMaterial = ""; //用来保存对象的材质名称
int[] buffer = new int[50000]; //用来读入不需要的数据
//读入赋予当前对象的材质名称
pPreviousChunk.bytesRead += getStr(ref strMaterial);
//遍历所有的纹理
for (int i = 0; i < pModel.numOfMaterials; i++)
{
//如果读入的纹理与当前纹理名称匹配
if (strMaterial.Equals(pModel.pMaterials[i].strName))
{
//设置材质ID
pObject.materialID = i;
//判断是否是纹理映射，如果strFile是一个长度大于1的字符串，则是纹理
if (pModel.pMaterials[i].strFile.Length > 0)
{
//设置对象的纹理映射标志
pObject.bHasTexture = true;
}
break;
}
else
{
//如果该对象没有材质，则设置ID为-1
pObject.materialID = -1;
}
}
pPreviousChunk.bytesRead += fread(ref buffer, pPreviousChunk.length - pPreviousChunk.bytesRead, m_FilePointer);
}
//读入RGB颜色
void ReadColorChunk(tMaterialInfo pMaterial, tChunk pChunk)
{
//读入颜色块信息
ReadChunk(m_TempChunk);
//读入RGB颜色
m_TempChunk.bytesRead += fread(ref pMaterial.color, m_TempChunk.length - m_TempChunk.bytesRead, m_FilePointer);
//增加读入的字节数
pChunk.bytesRead += m_TempChunk.bytesRead;
}
//读下一个块
private void ReadChunk(tChunk pChunk)
{
//pChunk.bytesRead = fread(ref pChunk.ID, 2, this.m_FilePointer);
Byte[] id = new Byte[2];
Byte[] length = new Byte[4];
pChunk.bytesRead = (UInt32)this.m_FilePointer.Read(id, 0, 2);
pChunk.bytesRead += (UInt32)this.m_FilePointer.Read(length, 0, 4);
pChunk.ID = (UInt32)(id[1] * 256 + id[0]);
pChunk.length = (UInt32)(((length[3] * 256 + length[2]) * 256 + length[1]) * 256 + length[0]);
}
//读入对象的UV坐标
void ReadUVCoordinates(t3DObject pObject, tChunk pPreviousChunk)
{
//为了读入对象的UV坐标，首先需要读入数量，再读入具体的数据
//读入UV坐标的数量
pPreviousChunk.bytesRead += fread(ref pObject.numTexVertex, 2, m_FilePointer);
//初始化保存UV坐标的数组
pObject.pTexVerts = new CVector2[pObject.numTexVertex];
//读入纹理坐标
pPreviousChunk.bytesRead += fread(ref pObject.pTexVerts, pPreviousChunk.length - pPreviousChunk.bytesRead, m_FilePointer);
}
//处理所有的文件中的对象信息
void ProcessNextObjectChunk(t3DModel pModel, t3DObject pObject, tChunk pPreviousChunk)
{
m_CurrentChunk = new tChunk();
//继续读入块的内容直至本子块结束
while (pPreviousChunk.bytesRead < pPreviousChunk.length)
{
ReadChunk(m_CurrentChunk);
if (m_CurrentChunk.ID == FileHead.OBJECT_MESH)//正读入的是一个新块
{
//使用递归函数调用，处理该新块
ProcessNextObjectChunk(pModel, pObject, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.OBJECT_VERTICES)//读入的是对象顶点
{
ReadVertices(pObject, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.OBJECT_FACES)//读入的是对象的面
{
ReadVertexIndices(pObject, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.OBJECT_MATERIAL)//读入的是对象的材质名称
{
//该块保存了对象材质的名称，可能是一个颜色，也可能是一个纹理映射。
//同时在该块中也保存了纹理对象所赋予的面
//下面读入对象的材质名称
ReadObjectMaterial(pModel, pObject, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.OBJECT_UV)//读入对象的UV纹理坐标
{
ReadUVCoordinates(pObject, m_CurrentChunk);
}
else
{
//掠过不需要读入的块
while (m_CurrentChunk.bytesRead != m_CurrentChunk.length)
{
int[] b = new int[1];
m_CurrentChunk.bytesRead += fread(ref b, 1, m_FilePointer);
}
}
//添加从最后块中读入的字节数
pPreviousChunk.bytesRead += m_CurrentChunk.bytesRead;
}
//当前快设置为前面的块
m_CurrentChunk = pPreviousChunk;
}
//处理所有的材质信息
void ProcessNextMaterialChunk(t3DModel pModel, tChunk pPreviousChunk)
{
//给当前块分配存储空间
m_CurrentChunk = new tChunk();
//继续读入这些块，直到该子块结束
while (pPreviousChunk.bytesRead < pPreviousChunk.length)
{
//读入下一块
ReadChunk(m_CurrentChunk);
//判断读入的是什么块
if (m_CurrentChunk.ID == FileHead.MATNAME)//材质的名称
{
//读入材质的名称
m_CurrentChunk.bytesRead += fread(ref pModel.pMaterials[pModel.numOfMaterials - 1].strName, m_CurrentChunk.length - m_CurrentChunk.bytesRead, m_FilePointer);
}
else if (m_CurrentChunk.ID == FileHead.MATDIFFUSE)//对象的RGB颜色
{
ReadColorChunk(pModel.pMaterials[pModel.numOfMaterials - 1], m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.MATMAP)//纹理信息头部
{
//进入下一个材质块信息
ProcessNextMaterialChunk(pModel, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.MATMAPFILE)
{
//读入材质文件名称
pModel.pMaterials[pModel.numOfMaterials - 1].strFile = base_dir;
m_CurrentChunk.bytesRead += fread(ref pModel.pMaterials[pModel.numOfMaterials - 1].strFile, m_CurrentChunk.length - m_CurrentChunk.bytesRead, m_FilePointer);
}
else
{
//掠过不需要读入的块
while (m_CurrentChunk.bytesRead != m_CurrentChunk.length)
{
int[] b = new int[1];
m_CurrentChunk.bytesRead += fread(ref b, 1, m_FilePointer);
}
}
//添加从最后块中读入的字节数
pPreviousChunk.bytesRead += m_CurrentChunk.bytesRead;
}
//当前快设置为前面的块
m_CurrentChunk = pPreviousChunk;
}
//读入对象的顶点
void ReadVertices(t3DObject pObject, tChunk pPreviousChunk)
{
//在读入实际的顶点之前，首先必须确定需要读入多少个顶点。
//读入顶点的数目
pPreviousChunk.bytesRead += fread(ref pObject.numOfVerts, 2, m_FilePointer);
//分配顶点的储存空间，然后初始化结构体
pObject.pVerts = new CVector3[pObject.numOfVerts];
//读入顶点序列
pPreviousChunk.bytesRead += fread(ref pObject.pVerts, pPreviousChunk.length - pPreviousChunk.bytesRead, m_FilePointer);
//因为3DMax的模型Z轴是指向上的，将y轴和z轴翻转——y轴和z轴交换，再把z轴反向
//遍历所有的顶点
//for (int i = 0; i < pObject.numOfVerts; i++)
//{
// float fTempY = pObject.pVerts[i].y;
// pObject.pVerts[i].y = pObject.pVerts[i].z;
// pObject.pVerts[i].z = -1 * fTempY;
//}
}
//读出3ds文件的主要部分
void ProcessNextChunk(t3DModel pModel, tChunk pPreviousChunk)
{
t3DObject newObject = new t3DObject();
int version = 0;
m_CurrentChunk = new tChunk();
// 下面每读一个新块，都要判断一下块的ID，如果该块是需要的读入的，则继续进行
// 如果是不需要读入的块，则略过
// 继续读入子块，直到达到预定的长度
while (pPreviousChunk.bytesRead < pPreviousChunk.length)
{
//读入下一个块
ReadChunk(m_CurrentChunk);
//判断ID号
if (m_CurrentChunk.ID == FileHead.VERSION)
{
m_CurrentChunk.bytesRead += fread(ref version, m_CurrentChunk.length - m_CurrentChunk.bytesRead, m_FilePointer);
// 如果文件版本号大于3，给出一个警告信息
if (version > 3)
{
Debug.WriteLine("Warning: This 3DS file is over version 3 so it may load incorrectly");
}
}
else if (m_CurrentChunk.ID == FileHead.OBJECTINFO)
{
//读入下一个块
ReadChunk(m_TempChunk);
//获得网络的版本号
m_TempChunk.bytesRead += fread(ref version, m_TempChunk.length - m_TempChunk.bytesRead, m_FilePointer);
//增加读入的字节数
m_CurrentChunk.bytesRead += m_TempChunk.bytesRead;
//进入下一个块
ProcessNextChunk(pModel, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.MATERIAL)//材质信息
{
//材质的数目递增
pModel.numOfMaterials++;
//在纹理链表中添加一个空白纹理结构
pModel.pMaterials.Add(new tMaterialInfo());
//进入材质装入函数
ProcessNextMaterialChunk(pModel, m_CurrentChunk);
}
else if (m_CurrentChunk.ID == FileHead.OBJECT)//对象的名称
{
//对象数目递增
pModel.numOfObjects++;
//添加一个新的tObject节点到对象的链表中
pModel.pObject.Add(new t3DObject());
//获得并保存对象的名称，然后增加读入的字节数
m_CurrentChunk.bytesRead += getStr(ref pModel.pObject[pModel.numOfObjects - 1].strName);
//进入其余对象信息的读入
ProcessNextObjectChunk(pModel, pModel.pObject[pModel.numOfObjects - 1], m_CurrentChunk);
}
else
{
// 跳过关键帧块的读入，增加需要读入的字节数 EDITKEYFRAME
// 跳过所有忽略的块的内容的读入，增加需要读入的字节数
while (m_CurrentChunk.bytesRead != m_CurrentChunk.length)
{
int[] b = new int[1];
m_CurrentChunk.bytesRead += fread(ref b, 1, m_FilePointer);
}
}
//添加从最后块中读入的字节数
pPreviousChunk.bytesRead += m_CurrentChunk.bytesRead;
}
//当前快设置为前面的块
m_CurrentChunk = pPreviousChunk;
}
