Merge pull request #314 from Unity-Technologies/UNI-23144-convert-to-prefab-dont-override-fbx

Uni 23144 convert to prefab dont override fbx

Author: vkovec

Assets/FbxExporters/Editor/ConvertToModel.cs

@@ -117,6 +117,29 @@ public static GameObject Convert (
                 string directoryFullPath = null,
                 string fbxFullPath = null)
             {
+                // Only create the prefab (no FBX export) if we have selected the root of a model prefab instance.
+                // Children of model prefab instances will also have "model prefab instance"
+                // as their prefab type, so it is important that it is the root that is selected.
+                //
+                // e.g. If I have the following hierarchy: 
+                //      Cube
+                //      -- Sphere
+                //
+                // Both the Cube and Sphere will have ModelPrefabInstance as their prefab type.
+                // However, when selecting the Sphere to convert, we don't want to connect it to the
+                // existing FBX but create a new FBX containing just the sphere.
+                PrefabType unityPrefabType = PrefabUtility.GetPrefabType(toConvert);
+                if (unityPrefabType == PrefabType.ModelPrefabInstance && toConvert.Equals(PrefabUtility.FindPrefabRoot(toConvert))) {
+                    // don't re-export fbx
+                    // create prefab out of model instance in scene, link to existing fbx
+                    var mainAsset = PrefabUtility.GetPrefabParent(toConvert) as GameObject;
+                    var mainAssetRelPath = AssetDatabase.GetAssetPath(mainAsset);
+                    var mainAssetAbsPath = Directory.GetParent(Application.dataPath) + "/" + mainAssetRelPath;
+                    SetupFbxPrefab(toConvert, mainAsset, mainAssetRelPath, mainAssetAbsPath);
+
+                    return toConvert;
+                }
+
                 if (string.IsNullOrEmpty(fbxFullPath)) {
                     // Generate a unique filename.
                     if (string.IsNullOrEmpty (directoryFullPath)) {
@@ -155,12 +178,27 @@ public static GameObject Convert (
                 // relative to the project, not relative to the assets folder.
                 var unityMainAsset = AssetDatabase.LoadMainAssetAtPath (projectRelativePath) as GameObject;
                 if (!unityMainAsset) {
-                    throw new System.Exception ("Failed to convert " + toConvert.name);;
+                    throw new System.Exception ("Failed to convert " + toConvert.name);
                 }
 
                 // Copy the mesh/materials from the FBX
                 UpdateFromSourceRecursive (toConvert, unityMainAsset);
 
+                SetupFbxPrefab (toConvert, unityMainAsset, projectRelativePath, fbxFullPath);
+
+                toConvert.name = Path.GetFileNameWithoutExtension (fbxFullPath);
+                return toConvert;
+            }
+
+
+            /// <summary>
+            /// Create the prefab and connect it to the given fbx asset. 
+            /// </summary>
+            /// <param name="toConvert">Hierarchy to convert.</param>
+            /// <param name="unityMainAsset">Main asset in the FBX.</param>
+            /// <param name="projectRelativePath">Fbx project relative path.</param>
+            /// <param name="fbxFullPath">Fbx full path.</param>
+            public static void SetupFbxPrefab(GameObject toConvert, GameObject unityMainAsset, string projectRelativePath, string fbxFullPath){
                 // Set up the FbxPrefab component so it will auto-update.
                 // Make sure to delete whatever FbxPrefab history we had.
                 var fbxPrefab = toConvert.GetComponent<FbxPrefab>();
@@ -179,9 +217,6 @@ public static GameObject Convert (
                         string.Format("Failed to create prefab asset in [{0}] from fbx [{1}]",
                             prefabFileName, fbxFullPath));
                 }
-
-                toConvert.name = Path.GetFileNameWithoutExtension (fbxFullPath);
-                return toConvert;
             }
 
             /// <summary>

Assets/FbxExporters/Editor/UnitTests/ConvertToModelTest.cs

@@ -256,5 +256,59 @@ public void TestInstanceNameMatchesFilename()
 
             Assert.AreEqual (Path.GetFileNameWithoutExtension (path), cube.name);
         }
+
+        [Test]
+        public void TestConvertModelInstance()
+        {
+            // expected result: prefab is linked to originally exported
+            //                  fbx and no new fbx is created.
+
+            // create hierarchy (Cube->Sphere)
+            var cube = GameObject.CreatePrimitive (PrimitiveType.Cube);
+            var sphere = GameObject.CreatePrimitive (PrimitiveType.Sphere);
+
+            sphere.transform.SetParent (cube.transform);
+
+            // export using regular model export
+            var filename = GetRandomFileNamePath();
+            GameObject fbxObj = ExportSelection (filename, cube);
+
+            // add back to scene
+            GameObject fbxInstance = PrefabUtility.InstantiatePrefab (fbxObj) as GameObject;
+            Assert.That (fbxInstance, Is.Not.Null);
+
+            // attach some components
+            var rigidBody = fbxInstance.AddComponent<Rigidbody> ();
+            Assert.That (rigidBody, Is.Not.Null);
+
+            var instanceSphere = fbxInstance.transform.GetChild (0);
+            Assert.That (instanceSphere, Is.Not.Null);
+
+            var boxCollider = instanceSphere.gameObject.AddComponent<BoxCollider> ();
+            Assert.That (boxCollider, Is.Not.Null);
+
+            // convert to prefab
+            GameObject converted = ConvertToModel.Convert (fbxInstance, Path.GetDirectoryName(filename));
+            Assert.That (converted, Is.EqualTo (fbxInstance));
+
+            // check meshes link to original fbx
+            var prefabCubeMesh = fbxInstance.GetComponent<MeshFilter>().sharedMesh;
+            Assert.That (prefabCubeMesh, Is.Not.Null);
+
+            var fbxObjAssetPath = AssetDatabase.GetAssetPath (fbxObj);
+
+            Assert.That (AssetDatabase.GetAssetPath (prefabCubeMesh), Is.EqualTo (fbxObjAssetPath));
+
+            var prefabSphere = fbxInstance.transform.GetChild (0);
+            Assert.That (prefabSphere, Is.Not.Null);
+            var prefabSphereMesh = prefabSphere.GetComponent<MeshFilter> ().sharedMesh;
+            Assert.That (prefabSphere, Is.Not.Null);
+
+            Assert.That (AssetDatabase.GetAssetPath (prefabSphereMesh), Is.EqualTo (fbxObjAssetPath));
+
+            // check that components are still there
+            Assert.That (fbxInstance.GetComponent<Rigidbody>(), Is.Not.Null);
+            Assert.That (prefabSphere.GetComponent<BoxCollider> (), Is.Not.Null);
+        }
     }
 }

Assets/FbxExporters/Editor/UnitTests/ExporterTestBase.cs

@@ -223,7 +223,10 @@ protected virtual GameObject ExportSelection(params Object[] selected)
         {
             // export selected to a file, then return the root
             var filename = GetRandomFileNamePath();
+            return ExportSelection (filename, selected);
+        }
 
+        protected virtual GameObject ExportSelection(string filename, params Object[] selected){
             Debug.unityLogger.logEnabled = false;
             var fbxFileName = FbxExporters.Editor.ModelExporter.ExportObjects (filename, selected) as string;
             Debug.unityLogger.logEnabled = true;