The slow undo is apparently a priority for developers

I spoke to a guy who holds a senior position at a company that uses Blender to make feature animation over the weekend. What’s cool about the open-source nature of Blender is that if a company (like the one mentioned here) is using it and finds some niggles, they can fix those in-house and send the code back to be included in future updates for all of us to benefit from.

I mentioned that I’ve started using Blender a lot in my workflow as a concept artist, but the undo was a serious issue. He hold me that the slow undo is of a high priority for them to fix. I mean it kinda goes without saying, but it was just a relief to speak to someone who is ACTUALLY working on fixing it.

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Slow undo is an issue with large scenes, which is understandable to certain degree. It is not always an issue as people seem to make it sound like. The users also have to be smart about their own scenes and assets, just throwing a lot of asset into your scene and expecting Blender to perform awesome at all times is not a realistic expectation. However it would be nice to get some performance improvements with undo for sure.

C’mon, @kkar. You should know as well as anybody that that’s glossing over the fact that 2.8 is far less responsive than 2.79b, not only with undos, regardless of scene size, but also in UI responsiveness.

In 2.79 (and previous) you could grab the gizmo and drag immediately. In 2.79 (and previous) you could hold down a modifier key (CTRL/ALT/SHIFT) and grab the gizmo and Blender would react.

In 2.8x, grab the gizmo and wait that fraction of a second before Blender responds. Pressing a modifier key and grabbing the gizmo? Blender 2.8x ignores the grab completely.

In any case, I’m glad someone is working on the undo situation.

Blender 2.8x’s interface is awesome all the time. Blender 2.79 and before’s performance was awesome all the time.


@wonderland78 Couple of months ago devs mentioned that they’re aware of the issue but it’s not easy to tackle (whole system must be changed or something). So I’m not expecting anything before 2.83 (I hope I’ll be wrong). Check this (and links in the post):

@kkar According to your analogy majority of the Blender community is not smart enough…

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that link above is exactly what I’m talking about where he shows a 20-30 second undo time. It’s, as we say in Britain, a piss take. Meaning, so far down the road of unreasonable as to be a joke.

name me one piece of software in the history of software that forces you to disable CTRL+Z because you knee-jerk hit it and find yourself going NOOO… sigh, I’ll make a cup of tea while I wait. It’s not a user fault issue.


I never had to wait 30 secs for an undo in my scenes, therefor I cant speak for others. Until there are improvements, there are work arounds in Blender like scene linking, collections, local view, groups, instancing, bounding box view, enabling only necessary modifiers, baking textures etc, you name it.

I am old school and I personally like scene/asset challanges, if you think I am trolling about it you are wrong. However like I said, it would be nice to have undo improvements. Until then bitching about it here is no help, and your only option is to start thinkering about work arounds.

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Have you guys seen the developers AMA from recent BCON? Maybe it’s of interest to you that there where some statements regarding these issues. Might be a good idea to check it out before getting into arguments over what they might be saying, thinking or doing.

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Not really, because I did not say that. What I said was that the user should be smart about his asset management which is about optimizing the scenes and the assets. If there are speed issues still, we are here to offer alternative solutions.

I built complex assets in Blender and I never experienced those issues as bad because I try to plan ahead and optimize as I go, and that is what I am recommending here. Practicing asset optimization is the best advice I can offer, until BF solves these issues for real. Btw BF developers are very good. if they were not able to solve the issue until now it means that it is a hard problem, not that they did not care.

I got some case of 30 and more second on a 1.9 millions scene. When i work on it now i close and open blender since it is faster than undo. The scene is too complicated to be separated in sections.

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No, the slow undo is not an issue with larger scenes. It’s an issue with any scenes which aren’t extremely trivial. There is a big difference between undo that doesn’t work well in poorly assembled scenes and undo that doesn’t work even in extremely carefully assembled scenes which reach as little as moderate complexity by today’s standards. Blender’s case is the latter one.

Luckily, you are one of the few people who’s profile actually links to some kind of portfolio, and I can tell most of your scenes fall into the “extremely trivial” category, since it’s mostly just solitary objects. No wonder you have no issue with undo then.

On the contrary, scene like this: which I’ve done in 3ds Max would be impossible to do in Blender simply because every undo key press would result in several minute long coffee break. That scene was very carefully assembled, pushing instancing and external reference system to its limit. But if you want to built large things, there’s just no way to cheat the general complexity, and even if there was, it would not make sense to do that just for the sake of satisfying broken undo system.


Anecdotal evidence is considered the least certain type of scientific information. Researchers may use anecdotal evidence for suggesting new hypotheses, but never as validating evidence.

In case you wonder why people pile onto you, it’s because you come off as smug and condescending.
It may not be intentional, but you just called us all dumb and unable to build proper scenes/assets.


No I do not, because people just like to harrass verbally here if one goes against the expected narrative. I have no shame in offering alternative take.

but you just called us all dumb and unable to build proper scenes/assets.

No I did not. I just recommended to optimize more and more until it works better. I recommended what I practice in my work. I hope you ladies and gentlemen realize that I face the same issues you face in Blender. I am not using another super duper Blender version. Undo lag does not bother me as much as it does some other users. However that does not mean I dismiss the issue, the reality is that there is nothing I can do to solve it so I go around the problem. I recommend that path to every Blender user.

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I count an implication as part of the communication.

Trust me when i say there is often no room for optimization because it already is optimal, I still need more performance. I need ALL the performance my hardware is capable off.
I believe you when you say this problem doesn’t bother you that much - good for you. But for some of us it has rather unpleasant consequences.
I was working on a project to test Blender and showcase its power, i now have to finish this project in Maya because the performance is grating on my nerves and there is still no (working) UDIM’s available.

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If you don’t have any problems with Ctrl-Z then you must probably not do any serious modeling.


It seems they will tackle it for Blender 2.82 hopefully

At 26:26min Bastian, a developer explains why Blender is slow compared to 2.79.
In short in 2.8 it redraws the code of too many things like modifier, etc… for every single object.

It would be optimal if the undo would only calculate the changes, which were done and not recalculate everything.

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I generally use Edit > Undo History. In 2.79 this was Ctrl-Alt-Z … and that key combo is not being used … can we bring it back?

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Hi, right click at Undo History open a menu where you can add the shortcut you like.

Cheers, mib

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Actually it is the oppposite, serious modelers do not need undo. The reason I am replying to your suggestion this way because number of undos someone performs has nothing to do with if someone is serious with modeling or not. On a side note, I modeled thousands of objects for many projects, and if not thousands, hundreds of them in Blender.

If someone is willing to lend me a test scene that demonstrates tha 20-30 secs undo issue, I would be more than happy to take a look at it and experience the pain of such undo.

Serious modelers don’t make mistakes. They physically remove the CTRL key and the Z key. They model blindfolded while quoting Morpheus. Only when you learn the truth, will you be above the masters, and enter the realm of the serious. Only when you learn, that all along… there was no undo.