When I'm working with complex scenes (a few million polygons with +- some subdivision), say you're making a weapon highpoly model, the Blender's Global Undo becomes extremely slow.

Even with simple changes in the object mode, moving something and undoing, applying a modifier and undoing it or anything like that Blender freezes for 5 - 10 seconds and then responds again.

This is making working on such scenes really difficult. And it isn't my specs, I've got an i7 6700, 24 gigs of memory etc.

Are there any options, maybe addons or something to help avoid this issue?

Thanks! :)

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    $\begingroup$ Maybe restricting the view plane to show only the part of your object you're working on, plus reducing the number of undo steps in Preferences. Not sure if that will help, haven't tested, just ideas. Also, lighten up the viewport settings in general, for example by making sure AO is off, and that kind of thing. You could also use the Mask Modifier to hide regions of your object, and hide separate objects altogether. $\endgroup$
    – Mentalist
    Sep 6, 2017 at 3:00
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    $\begingroup$ My understanding is that Blender has to recalculate the dependency graph on every global undo, and this makes things slow. There isn't really a good way around it. $\endgroup$
    – Mike Pan
    Sep 6, 2017 at 4:43
  • $\begingroup$ @Mentalist Viewport settings wouldn't give any effect, it's not related to graphics or actual preview. $\endgroup$
    – Aras
    Sep 13, 2017 at 19:14
  • $\begingroup$ @MikePan Thanks for the explanation though that's kinda sad... $\endgroup$
    – Aras
    Sep 13, 2017 at 19:14

2 Answers 2


The undo buffer works by actually saving the entire blend file in memory, and loading it to undo. If you have such big, complex files, that'll take a while.

A possible way to speed things up would be to enable Simplify (scene properties panel) to restrict the subdivision level, and to write parts of the scene to different blend files and link them into the scene (rather than having all data in one blend file).

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    $\begingroup$ Awesome idea, I'll try that out thanks! :) $\endgroup$
    – Aras
    Sep 13, 2017 at 19:29
  • $\begingroup$ @Aras if it helps, please accept this answer as the answer. $\endgroup$
    – dr. Sybren
    Sep 15, 2017 at 8:43
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    $\begingroup$ A linked scene can still slow the undo operation. $\endgroup$ Aug 26, 2019 at 15:30

I would try to divide the object into several parts and make the object I am working on visible in a layer. This would make the computer more relaxed Divide and conquer.

  • $\begingroup$ please only post in english. $\endgroup$
    – David
    Sep 14, 2017 at 11:22
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    $\begingroup$ That wouldn't help. As I said undoing even simple operations with any object like a cube or plane causes a short freeze. But thanks! It could help if the freeeze would be because of mesh density. $\endgroup$
    – Aras
    Sep 14, 2017 at 12:36

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