Mecanim - Blend Trees copy and paste?

Quick query - Is it possible to copy and paste blend trees? or rather to move them around.

My movement state machine consists of several nested blend trees. The other night, I needed to create a new blend tree at the top of the tree, and couldn't find anyway to do this, other than the time consuming practice of rebuilding the whole state.

 

I want to know this too...

 

bump... I'm currently copying manually a huge blend tree :-(

 

Bump: A cheat-y way to do this is to right-click somewhere, say "Copy State Machine", then paste that, then go into the sub-state, and drag out the Blend Tree into the main layer.

Should be fixed.

 

how do you drag out something?

 

The same here... Is there anybody who knows the answer? It's so fraustrating to do the whole job manauly again. I hope there will be a chance to do it through editor scripting.

 

what the f!

guys, we can't reconnect the blend-tree nodes or move them around :/
Plz fix
Write you

 

For the love of all things holy why cant you do this!
Blend trees could be really good but they are so inflexible. If you want to add something to the start of a blend tree you just have to manually rebuild the whole thing!?!
Well I'd better get back to rebuilding a whole massive blend tree (something that could take seconds).

 

Hey, at least we have the "Combined move-rotate-scale handle" for editing objects in scene view, that thing is the most important addition

 

Hehe , yeah I think pretty much everything gets prioritised before animation sadly, look at how long it took to get zoom in the view. Blend trees as they stand are a problem though because its a wall that stops you from experimenting and creating better animation.
You can build blend trees with through scripting, it's probably out of my skill level but I might have a look today and see if I can come up with something usable.

 

Well I got this happening, basically you put this script on a gameObject and fill out the array -

Press build and it creates a blend tree in the animator controller you referenced up the top.

It's still pretty bad but it's a start and it still might be less frustrating than setting it up the standard way.

If anyone wants to add to it, please do! I have limited experience with this stuff and the Unity folk are too busy to look at this low level fundamental stuff

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEditor.Animations;
5.  
6. public class BlendTreeCreator : MonoBehaviour
7. {
8.  
9.     public AnimatorController targetAnim;
10.  
11.     [System.Serializable]
12.     public class subMotionClass
13.     {
14.         public string name;
15.         public AnimationClip clip;
16.  
17.         [Space(12)]
18.         public List<subMotionClass> blendTree;
19.         public string parameter;
20.     }
21.     public subMotionClass motion;
22.  
23.     public void CheckIfStateExists()
24.     {
25.         for (int i = 0; i < targetAnim.layers.Length; i++)
26.         {
27.             for (int z = 0; z < targetAnim.layers[i].stateMachine.states.Length; z++)
28.             {
29.                 if (targetAnim.layers[i].stateMachine.states[z].state.name == motion.name)
30.                 {
31.                     //cant seem to delete states
32.                     //DestroyImmediate(targetAnim.layers[i].stateMachine.states[z].state);
33.                 }
34.             }
35.         }
36.     }
37.  
38.     public void BuildInitialBlendTree()
39.     {
40.         CheckIfStateExists();
41.  
42.         Debug.Log("Building Blend Tree");
43.         UnityEditor.Animations.BlendTree blendTree;
44.         targetAnim.CreateBlendTreeInController(motion.name, out blendTree, 0);
45.         blendTree.blendParameter = motion.parameter;
46.  
47.         PopulateBlendTree(motion, blendTree);
48.     }
49.  
50.     void PopulateBlendTree(subMotionClass subMotion, BlendTree subBlendTreeNode)
51.     {
52.         //add Clip to blendtree
53.         if (subMotion.clip != null)
54.         {
55.             subBlendTreeNode.AddChild(subMotion.clip);
56.         }
57.         else
58.         //create a new blend tree
59.         {
60.             for (int i = 0; i < subMotion.blendTree.Count; i++)
61.             {
62.                 UnityEditor.Animations.BlendTree newBlendTree = subBlendTreeNode.CreateBlendTreeChild(0);
63.                 newBlendTree.name = subMotion.blendTree[i].name;
64.                 newBlendTree.blendParameter = subMotion.blendTree[i].parameter;
65.                 PopulateBlendTree(subMotion.blendTree[i], newBlendTree);
66.             }
67.         }
68.     }
69. }

And the editor script for a button (put it in an editor folder)...

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEditor;
5.  
6. [CustomEditor(typeof(BlendTreeCreator))]
7. public class BlendTreeCreatorEditor : Editor
8. {
9.     public override void OnInspectorGUI()
10.     {
11.         BlendTreeCreator script = (BlendTreeCreator)target;
12.         base.OnInspectorGUI();
13.  
14.         if (GUILayout.Button("Build ", GUILayout.MinHeight(20)))
15.         {
16.             script.BuildInitialBlendTree();
17.         }
18.     }
19. }

 

Found this piece of code from unity feedback page:

Code (CSharp):

1. using UnityEditor;
2. using UnityEngine;
3. using UnityEditor.Animations;
4.  
5. public class CreateBlendtreeAsset : MonoBehaviour {
6.  
7. [MenuItem("AnimTools/GameObject/Asset from Blendtree")]
8. static void CreateBlendtree()
9. {
10. string path = "Assets/";
11.  
12. string currentPath = AssetDatabase.GetAssetPath(Selection.activeObject);
13. if (currentPath != null)
14. {
15. path = currentPath;
16. }
17.  
18. BlendTree BT = Selection.activeObject as BlendTree;
19.  
20. BlendTree BTcopy = Instantiate<BlendTree>(BT);
21.  
22. AssetDatabase.CreateAsset(BTcopy, AssetDatabase.GenerateUniqueAssetPath(path + "_" + BT.name + ".asset"));
23. }
24. }

It's an editor function that can save the selected blendtree as an asset in the animator's folder, you can drag n drop the blendtree asset to other nested blendtree hierarchy to reuse them. But there also seems to be some bugs in unity with this workflow. I haven't met it yet, but no guarantees.

 

Awesome, thanks for sharing that!
I’m about to be getting back into that side of things so I’ll check it out for sure.

 

Just met the bug I've mentioned before, it occurs when you replace a blendtree in your animator, if the blendtree is a local asset, it will be deleted, remember to backup all your local blendtree assets so won't panic when they got deleted by unity.

 

Okay I’ll keep that in mind, thanks for the help! I really appreciate that

 

This is what solved the problem for me, great idea, great tool, great developer! good job buddy.

 

I created an editor that works with the animator window that has the ability to duplicate blend trees. It can also be used to re-structure blend trees with drag/drop, and has a template system for saving off blend trees that you want to re-use. There are a ton of other time saving features that really help speed up editing animation controllers. Check it out here: https://assetstore.unity.com/packages/tools/animation/anim-tree-editor-161217

 

@Harekelas Hi man,

Trying to use this Editor Code gave me this error :
-----------
Assertion failed on expression: '(metaFlags & kStrongPPtrMask) == 0'
UnityEngine.Object:Instantiate(BlendTree)
CreateBlendtreeAsset:CreateBlendtree() (at Assets/Scripts/Editor/CreateBlendtreeAsset.cs:20)
-----------

Any Idea on what might be causing this and how to fix it? Thanks

 

Which unity version are you using? It may be caused by new versions changed some editor api.

 

I'm using version 2019.2.13f1

 

I haven't tried the code in 2019, guess unity changed some api broken the code. You can try going to the error line and see how to fix it.

 

Ah i see that's what's causing the problem then for sure.
Thing is i'm not familiar with Unity's API and have never worked with it, so unfortunately i can't try to fix this since i won't know what i'm supposed to do to begin with.
I'm going to just remake the blend trees manually
Thanks anyways for your replays, much appreciated

 

Hello!

Anyone who finds this on Google trying to copy/paste a blend tree, I have you covered!

I found the script on this page above and decided to rework it a little more to make it easier to use.

How to use it

1. Select the blend tree you'd like to copy.
2. Click the menu item AnimTools -> Blend Tree -> Copy Tree
3. Select (or create an empty) Blend Tree in the Animator window
4. Click the menu item AnimTools -> Blend Tree -> Paste

Copy this script, and save it into your project:

Code (CSharp):

1.  
2. using UnityEditor;
3. using UnityEditor.Animations;
4. using UnityEngine;
5. using System.Collections.Generic;
6.  
7. public class BlendTreeCopyPaste : MonoBehaviour
8. {
9.     const string workDir = "Assets/Editor/AnimTools/BlendTreeCopyPaste/";
10.     const string filename = "btcopy_";
11.     static int depth = 0;
12.     static string treePath = "";
13.     static string log = "";
14.     static BlendTree useTree = null;
15.     public class Pair<T1, T2>
16.     {
17.         public T1 First;
18.         public T2 Second;
19.         public Pair(T1 first, T2 second)
20.         {
21.             First = first;
22.             Second = second;
23.         }
24.     }
25.     static void makeWorkDirIfDoesntExist()
26.     {
27.         string path = "Assets";
28.         var split = workDir.Split('/');
29.         for (int i = 1; i < split.Length; i++)
30.         {
31.             string p = split[i];
32.             string newpath = path + "/" + p;
33.             if (!AssetDatabase.IsValidFolder(newpath))
34.                 AssetDatabase.CreateFolder(path, p);
35.             path = newpath;
36.         }
37.     }
38.     //===========================================================
39.     static void ClearConsole()
40.     {
41.         var logEntries = System.Type.GetType("UnityEditor.LogEntries, UnityEditor.dll");
42.         var clearMethod = logEntries.GetMethod("Clear", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public);
43.         clearMethod.Invoke(null, null);
44.     }
45.     //===========================================================
46.     public static bool isBlendTree(ChildMotion motion)
47.     {
48.         try { var treeType = (motion.motion as BlendTree).blendType; }
49.         catch { return false; }
50.         return true;
51.     }
52.     //===========================================================
53.     public static BlendTree getBlendTreeFromSelection()
54.     {
55.         BlendTree bt = useTree == null ? Selection.activeObject as BlendTree : useTree;
56.         if (bt == null) bt = (Selection.activeObject as AnimatorState).motion as BlendTree;
57.         return bt;
58.     }
59.     //===========================================================
60.     public static string getLogPath()
61.     {
62.         return Application.dataPath.Substring(0, Application.dataPath.Length - "Assets".Length) + workDir + "log.txt";
63.     }
64.     //===========================================================
65.     [MenuItem("AnimTools/Blend Tree/Copy Tree")]
66.     static void CopyBlendTree()
67.     {
68.         int notCopied = 0;
69.         // Get selected blendTree ...
70.         BlendTree bt = useTree == null ? getBlendTreeFromSelection() : useTree;
71.         if (bt == null)
72.         {
73.             Debug.LogError("BlendTreeCopy - Error: No selected blend tree");
74.             return;
75.         }
76.         // Copy directory ...
77.         makeWorkDirIfDoesntExist();
78.         log = "";
79.         depth = -1;
80.         treePath = "btcopy_";
81.         CopyTreeRecursive(bt, 0);
82.         // Save log
83.         ClearConsole();
84.         System.IO.File.WriteAllText(getLogPath(), log);
85.         Debug.Log("BlendTree copied!" + (notCopied > 0 ? " (" + notCopied.ToString() + " child blend trees not copied)" : ""));
86.     }
87.     //===========================================================
88.     public static void CopyTreeRecursive(BlendTree t, int ichild)
89.     {
90.         string oldpath = treePath;
91.  
92.         treePath += depth.ToString() + "," + ichild.ToString() + "_";
93.         // Save 't's motions ...
94.         BlendTree tclone = Instantiate<BlendTree>(t);
95.         string fpath = workDir + filename + depth.ToString() + "," + ichild.ToString() + ".asset";
96.         AssetDatabase.CreateAsset(tclone, workDir + filename + depth.ToString() + "," + ichild.ToString() + ".asset");
97.         log += fpath + "\n";
98.         // Save children (recursive) ...
99.         depth++;
100.         for (int i = 0; i < t.children.Length; i++)
101.             if (isBlendTree(t.children[i]))
102.                 CopyTreeRecursive(t.children[i].motion as BlendTree, i);
103.         depth--;
104.         treePath = oldpath;
105.     }
106.     //===========================================================
107.     [MenuItem("AnimTools/Blend Tree/Paste")]
108.     static void PasteBlendTree()
109.     {
110.         try
111.         {
112.             BlendTree bt = useTree == null ? getBlendTreeFromSelection() : useTree;
113.             var lines = System.IO.File.ReadAllLines(getLogPath());
114.             List<BlendTree> trees = new List<BlendTree>();
115.             for (int i = 0; i < lines.Length; i++)
116.                 trees.Add(AssetDatabase.LoadAssetAtPath<BlendTree>(lines[i]));
117.             for (int i = 1; i < lines.Length; i++)
118.             {
119.                 string l = lines[i].Substring((workDir + filename).Length);
120.                 l = l.Substring(0, l.Length - ".asset".Length);
121.                 if (l.Length == 0) continue;
122.                 Debug.Log(l);
123.                 var split = l.Split(',');
124.                 int a = int.Parse(split[0]);
125.                 int b = int.Parse(split[1]);
126.                 trees[a].children[b].motion = trees[i];
127.             }
128.             pasteBlendTreeSettings(bt, trees[0]);
129.             ClearConsole();
130.             Debug.Log("BlendTree pasted!");
131.         }
132.         catch
133.         {
134.             Debug.LogError("BlendTree - Error pasting!");
135.         }
136.     }
137.     public static void pasteBlendTreeSettings(BlendTree bt, BlendTree paste)
138.     {
139.         bt.blendType = paste.blendType;
140.         bt.minThreshold = paste.minThreshold;
141.         bt.maxThreshold = paste.maxThreshold;
142.         bt.useAutomaticThresholds = paste.useAutomaticThresholds;
143.         bt.hideFlags = paste.hideFlags;
144.         bt.children = paste.children.Clone() as ChildMotion[];
145.         bt.blendParameter = paste.blendParameter;
146.         bt.blendParameterY = paste.blendParameterY;
147.     }
148. }
149.  

After Unity sees it, a new menu item will appear at the top of Unity (AnimTools).

The script saves temporary files, so you can safely delete the old tree after it is copied, and also paste multiple times if you like.

Hopefully, that makes your life easier!

EDIT: Updated the script to not include the obsolete 'Boo.Lang' list, and instead use 'System.Collections.Generic'

 

Dude, thank you! Amazing that we've had the Animator for like 7 years now and being able to nest blend trees still isn't a thing.

 

This is perfect, thank you !!!!!!!!!!

 

Hi, there. Really would like to be able to use this and very kind of you to have created it - however, I'm getting the error "The type or namespace name 'Boo' could not be found (are you missing a using directive or an assembly reference?)" when unity tries to compile it. Any solutions?

Have looked around for a way to include Boo.Lang somewhere and have been unsuccessful.

 

Nevermind! Sorted it. I had an old version of Unity laying around and just copy/pasted the .dll into Assets/Plugins. Huge help!

 

Thanks for posting that, @gerudobomb. I'm surprised this isn't a standard function within Unity, so the script is deeply appreciated.

 

~7 years for this kind of problem
yo unity team, how to tag them this thread.

 

Awesome work!

 

Life saver! Work like a charm!

 

Seriously how is this Not an in-built feature already @Unity?

 

Update: It is an Issue since 9 years by now.
In four months and a bit it's 10 years, anybody planning anything for that big anniversary? @Unity maybe? How about deprecating Mecanim as a surprise for everyone?

Or maybe in another 10 years we might see this great discovery, thanks @gerudobomb, actually implemented in Unity!? -- 147 lines of code in 10 years, that's about 0.04 lines per day, could be possible one might think --

 

It seems the copies behave more like instances here, in that any changes made to nested child BTs is replicated between all copies and the original.
Could it be that nested child BTs gets copied with the same GUID or something so they all count as the same entry?

 

Is copy pasting blend trees possible in Unity yet?

Update: Seems not, but I was able to do it by opening the animator controller in a text editor and copying the data from the blend tree I wanted into a target blend tree I created in the editor. Just don't mess with the lines that look like

--- !u!206 &2243240913118475771

.