ZBrushCentral

zBrush never used to crash, now is crashing constantly

ZBrush Usage Questions
#1

Last week, I was working on a sculpt that got into the 30 million point mark. I worked on it for the next couple of days without any issues or crashes.

Suddenly, now whenever I try to open it, the file takes an abnormally long time to load (And if I click anywhere as it’s doing this, zBrush crashes) When the project finally does open, it’s able to load everything just fine, but it’s still very fickle about crashing. If I try to sculpt on the model, it crashes. If I try to reduce to a lower subdivision level, it crashes as well. Autosave (Or saving of any kind) also causes the program to crash.

At this point, I experimented to see just what was causing the problem.
For context, recently I used NoiseMaker on this character’s clothing, and needing that resolution increased the poly count quite a bit. That specific cloth subtool isn’t too taxing (only about 9 million points) but I deleted it as a test anyway.

For some reason, after I deleted it, the file stopped crashing altogether. (With 16 million total points)

Okay, fair enough, I thought it must be a file size thing. So for my next test, I did the opposite; I deleted everything but the cloth subtool, which left it at a mere 9 million points total. However, the program still crashes whenever I try to save, lower the subdivision level, etc. But the file had a smaller filesize at the point, I’m not sure what the issue could be. Is it something with that subtool itself?

Edit: Here’s some more info on my computer:
https://i.imgur.com/oE5sIGK.png
And the zBrush version I’m using is 4R7.

#2

First off, I’d recommend updating to zbrush 2018.1 since it’s a free update there has been a TON of fixes to performance/crash issues since 2015. That was 7 updates ago…

I’ve seen noise maker cause crashes. I’d turn it off if you can on the subtool that is causing issues.

Lastly, you could also try to export out each subtool at it’s highest level as a .ztl or .fbx or .obj and import them back in, into a fresh scene. You can rebuild the subdivision on a .obj or .fbx if needed.

#3

Thanks for the reply. I am pretty overdue for a zBrush update, so I went ahead and did that; Unfortunately, the crashes still occur the same as before. (But I’m liking the 2018 UI and other benefits, so I’m glad that I updated anyway)

Next, I tried to save it as a .ztl or export it as .obj, but the crashes still occurred then as well. I’m confused since I’ve worked with higher density meshes in the past, with noisemaker applied, so I’m not sure why it’s crashing now all of a sudden. Not ruling out it’s a RAM issue or something like that.

#4

Hmm that is odd that exporting a .obj and bringing that .obj into a fresh zbrush session still crashes…

If you want, you could zip it up and upload it to dropbox. PM me a link, Id be happy to take a look. There are a few other things I can try and I also have 128GB of ram on my machine so we could at least rule that out.

#5

That would be great, thanks for the offer. I’ll try some more stuff on my end, and if still nothing works, then I’ll PM it over to you later today.
(For clarification, the program crashes as it tries to export the .obj. Basically it never creates one sadly)

#6

are you sure you haven’t installed any different ui or maybe brush in the time it started to crash ?

#7

Yes, individual subtools can develop problematic geometry causing stability issues. Try remeshing the problem subtool to create entirely new geometry, and delete the problem subtool before saving.

That said, your object or file is likely too large for your system/ zbrush version to handle. If I recall there were stability improvements made with large file size handling sometime in the last couple versions, but there will always be a practical limit to how dense an object/ how large a file you can work with before zbrush will become increasingly unstable, eventually failing to save or load an object all together.

First off, 30 million polys is a lot for a single subtool. Zbrush can sculpt well on it, depending on system, but youre risking stability issues, especially when saving or loading, which can also lead to file corruption. Split that poly load into multiple subtools if possible, or retoplogize for more efficient poly distribution (more polys where you need finer detail, less where you dont). Zbrush can handle 100 million polygons split across multiple subtools easily, but starts to choke when a single subtool is especially dense. In my experience, if youre using all of ZBs tools well with good poly discipline, you shouldn’t ever need 30 mil+ for a single subtool. I personally try to keep mine under 18 mil (per subtool) max to avoid stability issues.

If you’re working on a project, instead of a tool file, it can be easy to lose track of how many different tools and subtools are loaded in the project and total file size can start to get out of control, causing stability issues.