Set the default filename to be the root gameobject

Unless there are multiple, in which case just do what we were doing
before

Author: vkovec

Assets/FbxExporters/Editor/ConvertToModel.cs

@@ -76,7 +76,8 @@ private static List<GameObject> OnConvertInPlace (GameObject [] unityActiveGOs)
                 string dirPath = Path.Combine (Application.dataPath, "Objects");
 
                 for(int n = 0; n < gosToExport.Length; n++){
-                    filePaths[n] = Path.Combine (dirPath, gosToExport[n].name + ".fbx");
+                    string filename = ModelExporter.ConvertToValidFilename (gosToExport [n].name + ".fbx");
+                    filePaths[n] = Path.Combine (dirPath, filename);
                 }
 
                 string[] fbxFileNames = new string[filePaths.Length];
@@ -91,7 +92,7 @@ private static List<GameObject> OnConvertInPlace (GameObject [] unityActiveGOs)
                 {
                     var fbxFileName = fbxFileNames [i];
                     if (fbxFileName == null) {
-                        Debug.Log (string.Format ("Warning: Export failed for GameObject {0}", gosToExport [i].name));
+                        Debug.LogWarning (string.Format ("Warning: Export failed for GameObject {0}", gosToExport [i].name));
                         continue;
                     }
 

Assets/FbxExporters/Editor/FbxExporter.cs

@@ -725,7 +725,10 @@ public static bool OnValidateMenuItem ()
             }
 
             // Add a menu item called "Export Model..." to a GameObject's context menu.
-            [MenuItem ("GameObject/Export Model... %e", false, 30)]
+            // NOTE: The ellipsis at the end of the Menu Item name prevents the context
+            //       from being passed to command, thus resulting in OnContextItem()
+            //       being called only once regardless of what is selected.
+            [MenuItem ("GameObject/Export Model...", false, 30)]
             static void OnContextItem (MenuCommand command)
             {
                 OnExport ();
@@ -956,13 +959,19 @@ private static void OnExport ()
                 					  ? Application.dataPath
                 					  : System.IO.Path.GetDirectoryName (LastFilePath);
 
-                var filename = string.IsNullOrEmpty (LastFilePath)
-                					 ? MakeFileName (basename: FileBaseName, extension: Extension)
-                					 : System.IO.Path.GetFileName (LastFilePath);
+                GameObject [] selectedGOs = Selection.GetFiltered<GameObject> (SelectionMode.TopLevel);
+                string filename = null;
+                if (selectedGOs.Length == 1) {
+                    filename = ConvertToValidFilename (selectedGOs [0].name + ".fbx");
+                } else {
+                    filename = string.IsNullOrEmpty (LastFilePath)
+                        ? MakeFileName (basename: FileBaseName, extension: Extension)
+                        : System.IO.Path.GetFileName (LastFilePath);
+                }
 
                 var title = string.Format ("Export Model FBX ({0})", FileBaseName);
 
-                var filePath = EditorUtility.SaveFilePanel (title, directory, filename, "");
+                var filePath = EditorUtility.SaveFilePanel (title, directory, filename, "fbx");
 
                 if (string.IsNullOrEmpty (filePath)) {
                     return;
@@ -1011,6 +1020,11 @@ private static void EnsureDirectory (string path)
                     Directory.CreateDirectory (fileInfo.Directory.FullName);
                 }
             }
+
+            public static string ConvertToValidFilename(string filename)
+            {
+                return System.Text.RegularExpressions.Regex.Replace (filename, "[" + new string(Path.GetInvalidFileNameChars()) + "]", "_");
+            }
         }
     }
 }