remove unused attribute.

code/D3MFExporter.cpp

@@ -55,7 +55,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 namespace Assimp {
 
 void ExportScene3MF( const char* pFile, IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* /*pProperties*/ ) {
-    D3MF::D3MFExporter myExporter( pFile, pIOSystem, pScene );
+    D3MF::D3MFExporter myExporter( pFile, pScene );
     if ( myExporter.validate() ) {
         bool ok = myExporter.exportArchive(pFile);
         if ( !ok ) {
@@ -68,9 +68,8 @@ namespace D3MF {
 
 #ifndef ASSIMP_BUILD_NO3MF_EXPORTER
 
-D3MFExporter::D3MFExporter( const char* pFile, IOSystem* pIOSystem, const aiScene* pScene )
-: mIOSystem( pIOSystem )
-, mArchiveName( pFile )
+D3MFExporter::D3MFExporter( const char* pFile, const aiScene* pScene )
+: mArchiveName( pFile )
 , m_zipArchive( nullptr )
 , mScene( pScene )
 , mBuildItems()

code/D3MFExporter.h

@@ -65,7 +65,7 @@ struct OpcPackageRelationship;
 
 class D3MFExporter {
 public:
-    D3MFExporter( const char* pFile, IOSystem* pIOSystem, const aiScene* pScene );
+    D3MFExporter( const char* pFile, const aiScene* pScene );
     ~D3MFExporter();
     bool validate();
     bool exportArchive( const char *file );
@@ -83,7 +83,6 @@ protected:
     void writeRelInfoToFile( const std::string &folder, const std::string &relName );
 
 private:
-    IOSystem *mIOSystem;
     std::string mArchiveName;
     zip_t *m_zipArchive;
     const aiScene *mScene;