ID3DXPMesh* PMesh = 0;

加载模型

hr = SourceMesh->OptimizeInplace(
	D3DXMESHOPT_ATTRSORT|
	D3DXMESHOPT_COMPACT|
	D3DXMESHOPT_VERTEXCACHE,
	(DWORD*)adjbuffer->GetBufferPointer(),
	(DWORD*)adjbuffer->GetBufferPointer(), //添加上优化后的邻接数组指针
	0,0
	);

if (FAILED(hr))
{
	::MessageBox(0, "OptimizeInplace-lost", 0, 0);
	return false;
}
//由原网格生成渐进网格（网格指针，优化前的邻接数组指针，默认顶点属性权重，默认顶点权重，尽可能简化，简化面数，把结果存到网格指针）
hr = D3DXGeneratePMesh(
	SourceMesh,
	(DWORD*)adjbuffer->GetBufferPointer(),
	0,0,1,
	D3DXMESHSIMP_FACE,
	&PMesh
	);

if (FAILED(hr))
{
	::MessageBox(0, "D3DXGeneratePMesh-lost", 0, 0);
	return false;
}

adjbuffer->Release();
//得到最大细节
DWORD maxfaces = PMesh->GetMaxFaces();
//设置细节
PMesh->SetNumFaces(maxfaces);

for (int i = 0; i < Mtrls.size(); i++)
{
	g_pd3dDevice->SetMaterial(&Mtrls[i]);
	g_pd3dDevice->SetTexture(0, Textures[i]);
	PMesh->DrawSubset(i);
	//绘制网格骨架，为了看到效果
	g_pd3dDevice->SetMaterial(&yellow_mtrl);
	g_pd3dDevice->SetRenderState(D3DRS_FILLMODE, D3DFILL_WIREFRAME);
	PMesh->DrawSubset(i);
	g_pd3dDevice->SetRenderState(D3DRS_FILLMODE, D3DFILL_SOLID);
}

int numfaces = PMesh->GetNumFaces();
if (::GetAsyncKeyState('A')&0x8000f)
{
	PMesh->SetNumFaces(numfaces + 10);
}

if (::GetAsyncKeyState('S')&0x8000f)
{
	PMesh->SetNumFaces(numfaces - 10);
}