diff --git a/3d-viewer/3d_draw.cpp b/3d-viewer/3d_draw.cpp
index 01421d9854..7aa39d1262 100644
--- a/3d-viewer/3d_draw.cpp
+++ b/3d-viewer/3d_draw.cpp
@@ -506,7 +506,7 @@ void EDA_3D_CANVAS::Draw3D_Via( SEGVIA* via )
 
         Draw3D_ZaxisCylinder( via->GetStart(), (outer_radius + inner_radius)/2,
                                   thickness, outer_radius - inner_radius,
-                                  zpos, biu_to_3Dunits );
+                                  zpos - (thickness/2), biu_to_3Dunits );
         if( layer >= top_layer )
             break;
     }
@@ -515,7 +515,7 @@ void EDA_3D_CANVAS::Draw3D_Via( SEGVIA* via )
     color = g_ColorsSettings.GetItemColor( VIAS_VISIBLE + via->GetShape() );
     SetGLColor( color );
     int height = g_Parm_3D_Visu.GetLayerZcoordBIU(top_layer) -
-                 g_Parm_3D_Visu.GetLayerZcoordBIU( bottom_layer );
+                 g_Parm_3D_Visu.GetLayerZcoordBIU( bottom_layer ) - thickness;
     int zpos = g_Parm_3D_Visu.GetLayerZcoordBIU(bottom_layer) + thickness/2;
 
     Draw3D_ZaxisCylinder( via->GetStart(), inner_radius + thickness/2, height,
diff --git a/3d-viewer/3d_draw_basic_functions.cpp b/3d-viewer/3d_draw_basic_functions.cpp
index 4fd075479d..06fbd76100 100644
--- a/3d-viewer/3d_draw_basic_functions.cpp
+++ b/3d-viewer/3d_draw_basic_functions.cpp
@@ -212,7 +212,7 @@ void Draw3D_SolidHorizontalPolyPolygons( const std::vector<CPolyPt>& aPolysList,
         return;
 
     // Build the 3D data : vertical side
-    Draw3D_VerticalPolygonalCylinder( polylist, aThickness, aZpos, false, aBiuTo3DUnits );
+    Draw3D_VerticalPolygonalCylinder( polylist, aThickness, aZpos - (aThickness / 2), false, aBiuTo3DUnits );
 }
 
 
diff --git a/3d-viewer/info3d_visu.cpp b/3d-viewer/info3d_visu.cpp
index 2a61f0ca04..6fe6c9248b 100644
--- a/3d-viewer/info3d_visu.cpp
+++ b/3d-viewer/info3d_visu.cpp
@@ -192,3 +192,19 @@ void INFO3D_VISU::InitSettings( BOARD* aBoard )
         m_LayerZcoord[layer_id] = zpos;
     }
 }
+
+/* return the Z position of 3D shapes, in 3D Units
+ * aIsFlipped: true for modules on Front (top) layer, false
+ * if on back (bottom) layer
+ * Note: in draw functions, the copper has a thickness = m_CopperThickness
+ * Vias and tracks are draw with the top side position = m_CopperThickness/2
+ * and the bottom side position = -m_CopperThickness/2 from the Z layer position
+ */
+double INFO3D_VISU::GetModulesZcoord3DIU( bool aIsFlipped )
+{
+    if(  aIsFlipped )
+        return m_LayerZcoord[LAYER_N_BACK] - ( m_CopperThickness / 2 );
+    else
+        return m_LayerZcoord[LAYER_N_FRONT] + ( m_CopperThickness / 2 );
+}
+
diff --git a/3d-viewer/info3d_visu.h b/3d-viewer/info3d_visu.h
index 5677cc9a55..ec2aa74d86 100644
--- a/3d-viewer/info3d_visu.h
+++ b/3d-viewer/info3d_visu.h
@@ -110,18 +110,11 @@ public: INFO3D_VISU();
 
     /**
      * function GetModulesZcoord3DIU
-     * @return the Z coordinate of the module, in 3D Units
+     * @return the Z position of 3D shapes, in 3D Units
      * @param aIsFlipped: true for modules on Front (top) layer, false
      * if on back (bottom) layer
-     * Used to know the Z position of 3D shapes
      */
-    double GetModulesZcoord3DIU( bool aIsFlipped )
-    {
-        if(  aIsFlipped )
-            return m_LayerZcoord[ADHESIVE_N_BACK] - m_NonCopperLayerThickness;
-        else
-            return m_LayerZcoord[ADHESIVE_N_FRONT] + m_NonCopperLayerThickness;
-    }
+    double GetModulesZcoord3DIU( bool aIsFlipped );
 
     /**
      * function GetLayerZcoordBIU