diff --git a/3d-viewer/3d_cache/3d_cache.cpp b/3d-viewer/3d_cache/3d_cache.cpp
index f1de8c2dbd..75f9ce686c 100644
--- a/3d-viewer/3d_cache/3d_cache.cpp
+++ b/3d-viewer/3d_cache/3d_cache.cpp
@@ -405,7 +405,7 @@ bool S3D_CACHE::loadCacheData( S3D_CACHE_ENTRY* aCacheItem )
     if( NULL != aCacheItem->sceneData )
         S3D::DestroyNode( (SGNODE*) aCacheItem->sceneData );
 
-    aCacheItem->sceneData = (SCENEGRAPH*)S3D::ReadCache( fname );
+    aCacheItem->sceneData = (SCENEGRAPH*)S3D::ReadCache( fname.ToUTF8() );
 
     if( NULL == aCacheItem->sceneData )
         return false;
@@ -475,7 +475,7 @@ bool S3D_CACHE::saveCacheData( S3D_CACHE_ENTRY* aCacheItem )
         }
     }
 
-    return S3D::WriteCache( fname, true, (SGNODE*)aCacheItem->sceneData );
+    return S3D::WriteCache( fname.ToUTF8(), true, (SGNODE*)aCacheItem->sceneData );
 }
 
 
diff --git a/3d-viewer/3d_cache/sg/ifsg_api.cpp b/3d-viewer/3d_cache/sg/ifsg_api.cpp
index bc5fa6e062..721dfc359e 100644
--- a/3d-viewer/3d_cache/sg/ifsg_api.cpp
+++ b/3d-viewer/3d_cache/sg/ifsg_api.cpp
@@ -29,6 +29,7 @@
 #include <wx/string.h>
 #include "plugins/3dapi/ifsg_api.h"
 #include "plugins/3dapi/sg_types.h"
+#include "plugins/3dapi/sg_version.h"
 #include "3d_cache/sg/sg_node.h"
 #include "3d_cache/sg/scenegraph.h"
 #include "3d_cache/sg/sg_appearance.h"
@@ -38,7 +39,6 @@
 #include "3d_cache/sg/sg_faceset.h"
 #include "3d_cache/sg/sg_normals.h"
 #include "3d_cache/sg/sg_shape.h"
-#include "3d_cache/sg/sg_version.h"
 #include "3d_cache/sg/sg_helpers.h"
 #include "3d_info.h"
 #include "plugins/3dapi/c3dmodel.h"
@@ -98,16 +98,21 @@ public:
 };
 
 
-bool S3D::WriteVRML( const wxString& filename, bool overwrite, SGNODE* aTopNode,
+bool S3D::WriteVRML( const char* filename, bool overwrite, SGNODE* aTopNode,
     bool reuse, bool renameNodes )
 {
-    if( wxFileName::Exists( filename ) )
+    if( NULL == filename || filename[0] == 0 )
+        return false;
+
+    wxString ofile = wxString::FromUTF8Unchecked( filename );
+
+    if( wxFileName::Exists( ofile ) )
     {
         if( !overwrite )
             return false;
 
         // make sure we make no attempt to write a directory
-        if( !wxFileName::FileExists( filename ) )
+        if( !wxFileName::FileExists( ofile ) )
             return false;
     }
 
@@ -133,14 +138,14 @@ bool S3D::WriteVRML( const wxString& filename, bool overwrite, SGNODE* aTopNode,
 
     VRML_LOCALE vrmlLocale;
     std::ofstream op;
-    op.open( filename.ToUTF8(), std::ios_base::out | std::ios_base::trunc
+    op.open( filename, std::ios_base::out | std::ios_base::trunc
                                  | std::ios_base::binary );
 
     if( !op.is_open() )
     {
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         wxString errmsg = _( "failed to open file" );
-        std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << filename.ToUTF8() << "'\n";
+        std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << filename << "'\n";
         return false;
     }
 
@@ -164,7 +169,7 @@ bool S3D::WriteVRML( const wxString& filename, bool overwrite, SGNODE* aTopNode,
 
     std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
     wxString errmsg = _( "problems encountered writing file" );
-    std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << filename.ToUTF8() << "'\n";
+    std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << filename << "'\n";
 
     return false;
 }
@@ -224,8 +229,13 @@ void S3D::DestroyNode( SGNODE* aNode )
 }
 
 
-bool S3D::WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode )
+bool S3D::WriteCache( const char* aFileName, bool overwrite, SGNODE* aNode )
 {
+    if( NULL == aFileName || aFileName[0] == 0 )
+        return false;
+
+    wxString ofile = wxString::FromUTF8Unchecked( aFileName );
+
     if( NULL == aNode )
     {
         #ifdef DEBUG
@@ -237,14 +247,14 @@ bool S3D::WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode )
     }
 
 
-    if( wxFileName::Exists( aFileName ) )
+    if( wxFileName::Exists( ofile ) )
     {
         if( !overwrite )
         {
             std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
             wxString errmsg = _( "file exists; not overwriting" );
             std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '";
-            std::cerr << aFileName.ToUTF8() << "'\n";
+            std::cerr << aFileName << "'\n";
             return false;
         }
 
@@ -254,20 +264,20 @@ bool S3D::WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode )
             std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
             wxString errmsg = _( "specified path is a directory" );
             std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '";
-            std::cerr << aFileName.ToUTF8() << "'\n";
+            std::cerr << aFileName << "'\n";
             return false;
         }
     }
 
     std::ofstream output;
-    output.open( aFileName.ToUTF8(), std::ios_base::out | std::ios_base::trunc
+    output.open( aFileName, std::ios_base::out | std::ios_base::trunc
                                 | std::ios_base::binary );
 
     if( !output.is_open() )
     {
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         wxString errmsg = _( "failed to open file" );
-        std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << aFileName.ToUTF8() << "'\n";
+        std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '" << aFileName << "'\n";
         return false;
     }
 
@@ -279,7 +289,7 @@ bool S3D::WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode )
     {
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         std::cerr << " * [INFO] problems encountered writing cache file '";
-        std::cerr << aFileName.ToUTF8() << "'\n";
+        std::cerr << aFileName << "'\n";
     }
     #endif
 
@@ -287,14 +297,19 @@ bool S3D::WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode )
 }
 
 
-SGNODE* S3D::ReadCache( const wxString& aFileName )
+SGNODE* S3D::ReadCache( const char* aFileName )
 {
+    if( NULL == aFileName || aFileName[0] == 0 )
+        return NULL;
+
+    wxString ofile = wxString::FromUTF8Unchecked( aFileName );
+
     if( !wxFileName::FileExists( aFileName ) )
     {
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         wxString errmsg = _( "no such file" );
         std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '";
-        std::cerr << aFileName.ToUTF8() << "'\n";
+        std::cerr << aFileName << "'\n";
     }
 
     SGNODE* np = new SCENEGRAPH( NULL );
@@ -309,7 +324,7 @@ SGNODE* S3D::ReadCache( const wxString& aFileName )
     }
 
     std::ifstream file;
-    file.open( aFileName.ToUTF8(), std::ios_base::in | std::ios_base::binary );
+    file.open( aFileName, std::ios_base::in | std::ios_base::binary );
 
     if( !file.is_open() )
     {
@@ -317,7 +332,7 @@ SGNODE* S3D::ReadCache( const wxString& aFileName )
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         wxString errmsg = _( "failed to open file" );
         std::cerr << " * [INFO] " << " '";
-        std::cerr << aFileName.ToUTF8() << "'\n";
+        std::cerr << aFileName << "'\n";
         return NULL;
     }
 
@@ -330,7 +345,7 @@ SGNODE* S3D::ReadCache( const wxString& aFileName )
         std::cerr << __FILE__ << ": " << __FUNCTION__ << ": " << __LINE__ << "\n";
         wxString errmsg = _( "problems encountered reading cache file" );
         std::cerr << " * [INFO] " << errmsg.ToUTF8() << " '";
-        std::cerr << aFileName.ToUTF8() << "'\n";
+        std::cerr << aFileName << "'\n";
         return NULL;
     }
 
@@ -458,16 +473,16 @@ void S3D::GetLibVersion( unsigned char* Major, unsigned char* Minor,
     unsigned char* Patch, unsigned char* Revision )
 {
     if( Major )
-        *Major = SG_VERSION_MAJOR;
+        *Major = KICADSG_VERSION_MAJOR;
 
     if( Minor )
-        *Minor = SG_VERSION_MINOR;
+        *Minor = KICADSG_VERSION_MINOR;
 
     if( Revision )
-        *Revision = SG_VERSION_REVNO;
+        *Revision = KICADSG_VERSION_REVISION;
 
     if( Patch )
-        *Patch = SG_VERSION_PATCH;
+        *Patch = KICADSG_VERSION_PATCH;
 
     return;
 }
diff --git a/include/plugins/3dapi/ifsg_api.h b/include/plugins/3dapi/ifsg_api.h
index 2687f45388..eca853a2b2 100644
--- a/include/plugins/3dapi/ifsg_api.h
+++ b/include/plugins/3dapi/ifsg_api.h
@@ -29,8 +29,6 @@
 #ifndef IFSG_API_H
 #define IFSG_API_H
 
-#include <wx/string.h>
-
 #include "plugins/3dapi/sg_types.h"
 #include "plugins/3dapi/sg_base.h"
 #include "plugins/3dapi/c3dmodel.h"
@@ -42,6 +40,13 @@ struct S3D_POINT;
 
 namespace S3D
 {
+    /**
+     * Function GetLibVersion retrieves version information of the
+     * kicad_3dsg library
+     */
+    SGLIB_API void GetLibVersion( unsigned char* Major, unsigned char* Minor,
+                                  unsigned char* Patch, unsigned char* Revision );
+
     // functions to extract information from SGNODE pointers
     SGLIB_API S3D::SGTYPES GetSGNodeType( SGNODE* aNode );
     SGLIB_API SGNODE* GetSGNodeParent( SGNODE* aNode );
@@ -64,7 +69,7 @@ namespace S3D
      * @param aNode is any node within the node tree which is to be written
      * @return true on success
      */
-    SGLIB_API bool WriteCache( const wxString& aFileName, bool overwrite, SGNODE* aNode );
+    SGLIB_API bool WriteCache( const char* aFileName, bool overwrite, SGNODE* aNode );
 
     /**
      * Function ReadCache
@@ -75,7 +80,7 @@ namespace S3D
      * if desired this node can be associated with an IFSG_TRANSFORM wrapper via
      * the IFSG_TRANSFORM::Attach() function.
      */
-    SGLIB_API SGNODE* ReadCache( const wxString& aFileName );
+    SGLIB_API SGNODE* ReadCache( const char* aFileName );
 
     /**
      * Function WriteVRML
@@ -87,7 +92,7 @@ namespace S3D
      * @param reuse should be set to true to make use of VRML DEF/USE features
      * @return true on success
      */
-    SGLIB_API bool WriteVRML( const wxString& filename, bool overwrite, SGNODE* aTopNode,
+    SGLIB_API bool WriteVRML( const char* filename, bool overwrite, SGNODE* aTopNode,
                     bool reuse, bool renameNodes );
 
     // NOTE: The following functions are used in combination to create a VRML
@@ -187,9 +192,6 @@ namespace S3D
      * creates and initializes an SMESH struct
      */
     SGLIB_API void Init3DMesh( SMESH& aMesh );
-
-    SGLIB_API void GetLibVersion( unsigned char* Major, unsigned char* Minor,
-        unsigned char* Patch, unsigned char* Revision );
 };
 
 #endif  // IFSG_API_H
diff --git a/3d-viewer/3d_cache/sg/sg_version.h b/include/plugins/3dapi/sg_version.h
similarity index 77%
rename from 3d-viewer/3d_cache/sg/sg_version.h
rename to include/plugins/3dapi/sg_version.h
index 31b20e4f4f..97d1423599 100644
--- a/3d-viewer/3d_cache/sg/sg_version.h
+++ b/include/plugins/3dapi/sg_version.h
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2015 Cirilo Bernardo <cirilo.bernardo@gmail.com>
+ * Copyright (C) 2016 Cirilo Bernardo <cirilo.bernardo@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -23,16 +23,16 @@
 
 /**
  * @file sg_version.h
- * defines the version number of 3DSG library. This file is parsed by
- * CMake to determine the version number of the 3DSG library.
+ * defines the library version of the intermediate scenegraph (SG)
+ * implementation
  */
 
 #ifndef SG_VERSION_H
 #define SG_VERSION_H
 
-#define SG_VERSION_MAJOR 1
-#define SG_VERSION_MINOR 0
-#define SG_VERSION_PATCH 0
-#define SG_VERSION_REVNO 0
+#define KICADSG_VERSION_MAJOR         1
+#define KICADSG_VERSION_MINOR         0
+#define KICADSG_VERSION_PATCH         0
+#define KICADSG_VERSION_REVISION      0
 
 #endif  // SG_VERSION_H
diff --git a/plugins/3d/idf/s3d_plugin_idf.cpp b/plugins/3d/idf/s3d_plugin_idf.cpp
index b5afb65f2e..f2e23f5e50 100644
--- a/plugins/3d/idf/s3d_plugin_idf.cpp
+++ b/plugins/3d/idf/s3d_plugin_idf.cpp
@@ -302,7 +302,7 @@ SCENEGRAPH* Load( char const* aFileName )
         wxString output = wxT( "_idf-" );
         output.append( fn.GetName() );
         output.append( wxT(".wrl") );
-        S3D::WriteVRML( output, true, (SGNODE*)(data), true, true );
+        S3D::WriteVRML( output.ToUTF8(), true, (SGNODE*)(data), true, true );
     }
     #endif
 
diff --git a/plugins/3d/vrml/vrml.cpp b/plugins/3d/vrml/vrml.cpp
index 33f195cbd9..5a1dae3013 100644
--- a/plugins/3d/vrml/vrml.cpp
+++ b/plugins/3d/vrml/vrml.cpp
@@ -276,7 +276,7 @@ SCENEGRAPH* Load( char const* aFileName )
 
         output.append( fn.GetName() );
         output.append( wxT(".wrl") );
-        S3D::WriteVRML( output, true, (SGNODE*)(scene), true, true );
+        S3D::WriteVRML( output.ToUTF8(), true, (SGNODE*)(scene), true, true );
     }
     #endif