Maniphest T74072

Having Global Undo enabled causes freezes while editing objects in huge files
Closed, Archived

Assigned To
Brecht Van Lommel (brecht)
Authored By
Oliver J. Post (Ole)
Feb 21 2020, 12:54 PM
Tags
  • BF Blender
Subscribers
Ankit Meel (ankitm)
Brecht Van Lommel (brecht)
Oliver J. Post (Ole)
Yen Huynh (tonismogames)

Description

System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: rBf1aa4d18d49d

Short description of error
A well known issue with Blender is the slow undo on complex files, I am aware that the developers know about this issue. However, it seems that even having global undo enabled causes Blender to freeze while doing very basic adjustments in complex files. I have made a video which shows the issue most clearly:
https://www.youtube.com/watch?v=m1VsIQYlWzg&feature=youtu.be
As you can see in the video, the performance is so slow that it makes working on files like this very frustrating. I assume this freezing is caused by Blender saving the full file every time I make a simple adjustment. (One thing that I cannot explain is why the first selection after switching off Global Undo is still slow, everything after is much faster)

This means that, to have workable complex ArchViz files, one has to turn off Global Undo (which is of course by far a perfect solution, since a lot of things cannot be undone then anymore)

Some useful information:

  1. The file is 2.8GB big, it contains a large amount (ca. 1 million) grass particles which are disabled in the viewport
  2. I have 32GB of RAM, Blender is not even close to using it all
  3. This is an extreme scenario, usually, the freeze takes about 2-5 seconds depending on how complex the moved object is
  4. I tested this on another complex file, and it also showed a speed boost after turning off global undo (the freezing was less extreme in this file, so the difference in speed was smaller)

Exact steps for others to reproduce the error

  1. Have a file that is very complex and large (e.g. multiple Gigabytes big)
  2. Select a reasonably complex object (the oven used as example is a 50k tris object)
  3. Duplicate or move it
  4. Blender freezes for a couple of seconds

Event Timeline

Oliver J. Post (Ole) created this task.Feb 21 2020, 12:54 PM
Ankit Meel (ankitm) renamed this task from Freeze - Having Global Undo enabled causes freezes while editing and duplicating objects to Having Global Undo enabled causes freezes while editing objects in huge files.Feb 21 2020, 1:15 PM
Brecht Van Lommel (brecht) closed this task as Archived.Mar 3 2020, 12:03 AM
Brecht Van Lommel (brecht) claimed this task.
Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).

We are aware of this issue as well, it's what section 3 in T60695: Optimized per-datablock global undo is intended to address. So we plan to tackle it at some point, but it's outside the scope of the bug tracker.

Ankit Meel (ankitm) added subscribers: Yen Huynh (tonismogames), Ankit Meel (ankitm).