Saves a data object and its children to a .x file on disk.
HRESULT Save();
None.
If the method succeeds, the return value is S_OK. If the method fails, the return value can be the following: D3DXFERR_BADOBJECT.
After this method succeeds, ID3DXFileSaveObject::AddDataObject, ID3DXFileSaveData::AddDataObject and ID3DXFileSaveData::AddDataReference can no longer be called until a new ID3DXFile object is created.
Header: Declared in D3dx9xof.h.