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;

}