Problems with undo

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Asticles
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Problems with undo

Post by Asticles »

Hi all

I've done with Luxcore 2 archviz mid sized projects so far, and with the two, doing undo gives me instant crash with this error:

Code: Select all

Error: EXCEPTION_ACCESS_VIOLATION
When scene is small, undo works fine, but it starts to fail when it gets bigger and now it's unusuable.
I cannot post the files, but I ask you to check this, which is a real pain.

Have tried to unpack all files, and work without addons except lux. Same error.

Thanks
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B.Y.O.B.
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Re: Problems with undo

Post by B.Y.O.B. »

I have encountered this in the past a few times, but I could never reproduce it (it crashed once, but after reloading the file it worked fine).
If you have a scene that reproduces it reliably, it would help me a lot if you could send it to me.

I fear that this bug might be very hard to find, it could even be a bug in Blender itself.
You could wait for the 2.8 port of BlendLuxCore and see if the switch to 2.8 fixes it.
Asticles
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Re: Problems with undo

Post by Asticles »

Still with undo problems, since it seems that 2.80 version is a bit far away, what can I do? I cannot work with this issue, and it happens at work, at home, now on 3 different computers. All with windows 10.

Could be some latency issue? From the absolute ignorance.

Please help.
wasd
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Re: Problems with undo

Post by wasd »

Asticles wrote: Sat Feb 23, 2019 10:31 am Could be some latency issue? From the absolute ignorance.
Do not undo ;)
It's because this part of blender was coded without using hands. From my observations it's free RAM issue. Depending on what you're trying to undo some decent amount of RAM could be needed, so if there's not enough RAM and not enough swap, blender crashes. I think so because it happen to me more often when I'm low on free RAM.
I have only 8 GB RAM, so that's what I do:
  • make sure I have enough swap
  • free as much RAM as I can
  • do not undo. It's unreliable piece of bullshit
CPU Bidir + Metropolis | Core i5-4570
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xlxs
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Re: Problems with undo

Post by xlxs »

A wild guess(I haven't managed to crash anything with undo yet): since some suggest it has to do with the memory, you can try setting in user preferences>editing>"global undo as ticked", and also setting the memory limit to something bigger.
Asticles
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Re: Problems with undo

Post by Asticles »

I think I have enough free ram and currently memory limit is set to 0.

Have tested disabling global undo, but this disables moving objects' undo, so it's not usable to me.

Also have tested setting a low memory limit, but the program also crashes.

Currently, when I have to undo, I save the scene first, just in case. But I cannot work without undo.

Best regards.
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FarbigeWelt
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Re: Problems with undo

Post by FarbigeWelt »

Asticles wrote: Sun Feb 24, 2019 6:23 pm I think I have enough free ram and currently memory limit is set to 0.

Have tested disabling global undo, but this disables moving objects' undo, so it's not usable to me.

Also have tested setting a low memory limit, but the program also crashes.

Currently, when I have to undo, I save the scene first, just in case.

Best regards.
Hi,
Did you check if there orphan data? Sometimes there a lot if them.
I am an frequent undoer, ceash happens really, but very rare. And there is in most case an auto save there with all the work done 2 minutes ago.

Much more annoying is this the use of ctrl-c of objects, actually I avoid it but sometiimes I hit it instead of alt-c. (But material nodes can be copied with ctrl-c.)

If I were you, I keept undo default settings and use the autosave.
Light and Word designing Creator - www.farbigewelt.ch - aka quantenkristall || #luxcorerender
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B.Y.O.B.
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Re: Problems with undo

Post by B.Y.O.B. »

I am aware of this problem and I think it is a bug in the addon, I am probably using the Blender API wrong somewhere. But I'm not entirely sure, as I wrote above, it could very well also be a bug in Blender (the datablock ID pointer patch was a bit sketchy to begin with and had bugs in the past, this could be one possible source).

The main problem about this bug is the randomness: I have encountered the crashes myself, but whenever I tried to reproduce them, they were gone.
I would probably have to start Blender from a debugger and use it for days until I encounter a crash to find out the line in the source code where the crash occurs. And without reproducability it's impossible to find out if I found all sources of crashes or just one, and if I fixed it.

So unfortunately, I can't offer you a quick solution.
Maybe the problem is gone when we switch to 2.8.
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Re: Problems with undo

Post by Fox »

For me the undo memory feature is too slow with big blend files like 7GB uncompressed, but blender doesn't crash.
Blender only crashes when i stop high-res render 50/50 change :D
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