建立自己的3D静态模型文件

跟着我一步一步来吧（我的思路和过程）。
我有一个能画出微软例子中tiger.x的工程，其中创建Mesh的代码片断如下（代码中有一些变量在.h文档中定义的）：
HRESULT CMyMesh::Create( LPDIRECT3DDEVICE9 pDevice, string MeshFile )
{
if( pDevice == NULL )
return E_FAIL;
LPD3DXBUFFER pD3DXMtrlBuffer;
if( FAILED( D3DXLoadMeshFromX( MeshFile.c_str(), D3DXMESH_SYSTEMMEM, pDevice, NULL, &pD3DXMtrlBuffer, NULL, &NumOfMaterials, &Mesh ) ) )
return E_FAIL;

D3DXMATERIAL* d3dxMaterials = (D3DXMATERIAL*)pD3DXMtrlBuffer->GetBufferPointer();
MeshMaterials = new D3DMATERIAL9[NumOfMaterials];
MeshTextures = new LPDIRECT3DTEXTURE9[NumOfMaterials];

for( DWORD i = 0; i < NumOfMaterials_; i ++ )
{
MeshMaterials[i] = d3dxMaterials[i].MatD3D;
MeshMaterials[i].Ambient = MeshMaterials[i].Diffuse;
MeshTextures[i] = NULL;
if( d3dxMaterials[i].pTextureFilename != NULL && lstrlen(d3dxMaterials[i].pTextureFilename) > 0 )
{
if( FAILED( D3DXCreateTextureFromFile( pDevice, d3dxMaterials[i].pTextureFilename, &MeshTextures[i] ) ) )
return E_FAIL;
}
}

pD3DXMtrlBuffer->Release();
return S_OK;
}

画这个Mesh的代码如下：
void CMyMesh::Render( LPDIRECT3DDEVICE9 pDevice )
{
for( DWORD i = 0; i < NumOfMaterials; i ++ )
{
pDevice->SetMaterial( &MeshMaterials[i] );
pDevice->SetTexture( 0, MeshTextures[i] );

Mesh->DrawSubset( i );
}
}

我们先想办法替换DrawSubset函数，代码如下：
void CMyMesh::Render( LPDIRECT3DDEVICE9 pDevice )
{
LPDIRECT3DVERTEXBUFFER9 pVertexBuffer;
LPDIRECT3DINDEXBUFFER9 pIndexBuffer;
DWORD dwNumBytesPerVertex;
DWORD dwFVF;
DWORD dwNumVertex;
DWORD dwFaces;
Mesh->GetVertexBuffer(&pVertexBuffer);
Mesh->GetIndexBuffer(&pIndexBuffer);
dwNumBytesPerVertex = Mesh->GetNumBytesPerVertex();
dwFVF = Mesh->GetFVF();
dwNumVertex = Mesh->GetNumVertices();
dwFaces = Mesh->GetNumFaces();

pDevice->SetStreamSource(0, pVertexBuffer, 0, dwNumBytesPerVertex);
pDevice->SetFVF(dwFVF);
pDevice->SetTexture(0, MeshTextures[0]);
pDevice->SetMaterial(&MeshMaterials[0]);
pDevice->SetIndices(pIndexBuffer);
pDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, dwNumVertex, 0, dwFaces);
}

虽然MeshTextures和MeshMaterials处有点问题，但是我们知道了画tiger.x的时候都需要什么东西：
VB,IB,NumBytesPerVertex,FVF,NumVertex,Faces,Texture,Material
那么我们将这些东西保存到文件中，不就和.x文件目的相同了么， 并且可以绕过D3DXMesh了。那么这些东西怎么得到呢：我修改了Create部分的代码：

HRESULT CMyMesh::Create( LPDIRECT3DDEVICE9 pDevice, string MeshFile )
{
if( pDevice == NULL )
return E_FAIL;

LPD3DXBUFFER pD3DXMtrlBuffer;
if( FAILED( D3DXLoadMeshFromX( MeshFile.c_str(), D3DXMESH_SYSTEMMEM, pDevice, NULL, &pD3DXMtrlBuffer, NULL, &NumOfMaterials, &Mesh ) ) )
return E_FAIL;

D3DXMATERIAL* d3dxMaterials = (D3DXMATERIAL*)pD3DXMtrlBuffer->GetBufferPointer();
MeshMaterials = new D3DMATERIAL9[NumOfMaterials];
MeshTextures = new LPDIRECT3DTEXTURE9[NumOfMaterials];

for( DWORD i = 0; i < NumOfMaterials_; i ++ )
{
MeshMaterials_[i] = d3dxMaterials[i].MatD3D;
MeshMaterials_[i].Ambient = MeshMaterials_[i].Diffuse;
MeshTextures_[i] = NULL;
if( d3dxMaterials[i].pTextureFilename != NULL && lstrlen(d3dxMaterials[i].pTextureFilename) > 0 )
{
FILE* fp;
int nLen = 0;
char* pBuf;
if(fp=fopen( d3dxMaterials[i].pTextureFilename, "rb" )) {
fseek(fp,0,SEEK_END);
nLen = ftell(fp);
fseek(fp,0,SEEK_SET);
pBuf = new char[nLen];
fread(pBuf,1,nLen,fp);
fclose(fp);
}
HRESULT hr = D3DXCreateTextureFromFileInMemory(D3DDevice,pBuf,nLen,&MeshTextures[i]);
delete [] pBuf;

//HRESULT hr = D3DXCreateTextureFromFile( D3DDevice_, d3dxMaterials[i].pTextureFilename, &MeshTextures_[i] );
if( FAILED( hr ) )
return E_FAIL;
}
}

//下面是增加的内容
FILE* fp;
if( ( fp = fopen("tiger.o","w") ) != NULL ) {
LPDIRECT3DVERTEXBUFFER9 pVertexBuffer;
LPDIRECT3DINDEXBUFFER9 pIndexBuffer;
D3DVERTEXBUFFER_DESC desc;
D3DINDEXBUFFER_DESC idesc;

Mesh->GetVertexBuffer(&pVertexBuffer);
Mesh->GetIndexBuffer(&pIndexBuffer);
pVertexBuffer->GetDesc( &desc );
pIndexBuffer->GetDesc( &idesc );

VOID* pVBData = NULL;
VOID* pIBData = NULL;

pVertexBuffer->Lock( 0, 0, (VOID**)&pVBData, 0 );
pIndexBuffer->Lock( 0, 0, (VOID**)&pIBData, 0 );

DWORD dwFVF = Mesh->GetFVF();
DWORD dwNumBytesPerVertex = Mesh->GetNumBytesPerVertex();
DWORD dwNumFaces = Mesh->GetNumFaces();

//怎么样？该有的都有了吧，要怎么保存就看你的了
//这段代码显然不完善，你需要自己去完善它
//有人说了你光考虑了Mesh，还有多AnimationSet等等东西呢？
//这里本来就只是建立静态模型，当然没有AnimationSet啦。动画的部分我后面在写吧。

pVertexBuffer->UnLock();
pIndexBuffer->UnLock();

fclose(fp);
}
//增加结束

pD3DXMtrlBuffer->Release();
return S_OK;
}