Home Technical Talk

Certain "Homemade" matcaps make ZBrush very unstable and crash often

polycounter lvl 7
Offline / Send Message
Pinned
Erwin0265 polycounter lvl 7
A few projects ago, I played around with ZBrush's matcaps and materials to try to create some realistic bone and teeth materials (I mainly use CT Scan data to create my sculpts of skulls and skeletons).
The first time I used them, they worked well and without issue; but now, they are almost unusable.
I van put the matcap on a sphere or other similar topology but not on my very complex skull sculpts with any certainty that they will not cause a crash.
Many of the materials I "created" are mixes of others' matcaps and sometimes one particular matcap is more "sensitive" than another (right now, on of my materials (E-Bleached Teeth 03) I can't use at all.
I have tried retopologizing and UV-ing from a Dynamesh (as the simple meshes from ZBrush are UV-ed) but there was no difference.
I have also "rebuilt" the materials to see if that would help.
Sometimes I find that a certain matcap has an issue with one of the channels (I have made some materials trishaders to get the effect I'm after.
I can't add a matcap, so I added a screencap showing the settings of all three shader channels.
I hope that someone has perhaps experienced this themselves and can help me.
Thanks in advance (and for taking the time to read this lengthy post)  - plmk if there is something that I have left out that you need to know............

Replies

  • Erwin0265
    Offline / Send Message
    Erwin0265 polycounter lvl 7
  • Eric Chadwick
    This was posted during a long holiday for members in the USA, so you may not see responses for a while.

    You could share a matcap by sticking it in a ZIP file. It might also help to share the exact version number of the ZBrush you're using, along with some info about your setup... OS, CPU, RAM, GPU. 
  • Erwin0265
    Offline / Send Message
    Erwin0265 polycounter lvl 7
    This was posted during a long holiday for members in the USA, so you may not see responses for a while.

    You could share a matcap by sticking it in a ZIP file. It might also help to share the exact version number of the ZBrush you're using, along with some info about your setup... OS, CPU, RAM, GPU. 
    Thanks for that!
    The most problematic matcaps have been attached. I have found that framing a subtool with the matcap several times causes a crash; multiple movements (zoom, rotate mostly).
    My only solution has been to have a ZBrush inclusive matcap on the subtools, do my posing/positioning (not much posing with skulls) and then putting the bone/teeth matcap back on (the teeth I put on by Fill object and the bone I leave as displaying the active material {it seems to put less stress on the issue}).
    BTW; the materials will look terrible as they don't have the right light setup - but I have found the lights to make no difference with the issue so rather than complicate things by adding more variables..)
    I'm currently using ZBrush 2024.0.4 (.5 I found to be very unstable); but I've also tried ZBrush 2022 & 2023 with the exact same results.
    Larger subtools make the issue worse (skull sculpts, whether they be decimated from a Dynamesh subtool, or a subdivided and UV'd one make little [aka, no) difference.
    I have yet to try baking the matcap into a texture map as ZB crashes before I can ever get that far.
    Win 10 custom
    Intel Core i7 5920K
    128GB RAM DDR4
    Nvidia GeForce RTX 3060

    I think that covers all of your questions.
    Yes, she's an older beast and I do intend to update (I think the MB and CPU are the bottleneck and a newer MB can allow for more RAM for other programs that I use for processing the raw CT scan data)...


  • pxgeek
    Offline / Send Message
    pxgeek greentooth
    damn, those shader settings look daunting!!
    The bigger of the two matcaps you shared also crashed for me when zooming. I was able to fix it by clearing out the surface bump texture in S3 and also set the CanvasBump scale to 1 just for good measure...it didn't look like there was any noticeable difference in the visual output.
    It's somewhat of a large texture too and non square, so if you really need it, consider resizing to something like 512 or even 256 and let tiling do the work.
  • Erwin0265
    Offline / Send Message
    Erwin0265 polycounter lvl 7
    pxgeek said:
    damn, those shader settings look daunting!!
    The bigger of the two matcaps you shared also crashed for me when zooming. I was able to fix it by clearing out the surface bump texture in S3 and also set the CanvasBump scale to 1 just for good measure...it didn't look like there was any noticeable difference in the visual output.
    It's somewhat of a large texture too and non square, so if you really need it, consider resizing to something like 512 or even 256 and let tiling do the work.
    Some great suggestions, pxgeek (please excuse any typos; one of my snakes bit me 3 weeks ago and it's still like typing with a frankfurt; so I'm using my 'rude finger instead' - getting an X-ray tomorrow. Been bitten by snakes plenty of times ; never had issues like this).
    So, yeah (I waffle too much) 
    I'll give 'em a try tomorrow (it's 3:15AM here right now - the joys of insomnia).
    Thanks; I will return to report - good or bad (I hate   those rude pricks that never respond after you solve their problem,,, eh, autocorrect can be awesome...

    Still working; trying to work out what materials I used for what effect (I take a shit-ton of notes, but there is still something I miss out).
    But I will keep you updated...
  • Erwin0265
    Offline / Send Message
    Erwin0265 polycounter lvl 7
    pxgeek, I have no idea why, but as the MOST problematic of the matcaps, I took all of your suggestions and it was the very first time that ZBrush didn't crash when I hit the 'F' key (as in 'F' for.... :).... Frame).
    One thing I didn't do was change the texture in shader 2 as it came with the original matcap that I used to "build" my matcap from*. So figured, "it's worked for over a decade; try not to 'fix' what ain't broke."
    I haven't done much testing as I want to create some renders before Murphy's Law steps in....

    *AL Ossuary; which I'm sure almost everyone who has used ZBrush for more than a few months is aware of. The matcaps created by Alan Lewis almost 15 years ago are still a solid "go to" set of matcaps - best of all; they're free!
    You can find them on the Pixologic... @!#^%$# Maxon website under resources (I think - I try my best to avoid the Maxon site lest it infect my PC as it has ZBrush itself)...
    I'll do my best to update here as I have to get one of my snake's teeth removed from my finger (so say-eth the X-ray). Thanks Notch, this is what I get for rescuing you from the bin (not a figurative bin; an actual bin. A friend was at a snake breeder's place and saw him throw my toothy friend in the bin! When asked, the breeder said, "he won't sell; he's deformed". My friend asked if he could take him which was fine to the breeder. Apparently, having 3 vertebrae out of buggered-if-I-know how many vertebrae, fused meant he was deformed and "Worthless". I've had him for 13 years and this is the first time he's bit me as a sub-adult [he's my li'l baby at only about 5'].
    AND I'm waffling again. Thanks for the help pxgeek. I'll hopefully get back to you when my finger gets some feeling back in the tip (had to be my index finger on my RHand)...
  • Erwin0265
    Offline / Send Message
    Erwin0265 polycounter lvl 7
    Follow up to previous post.
    Many thanks to pxgeek for the suggestions that basically made it possible for me to render my ZBrush sculpts using the matcaps I had created for the job.
    By removing the alpha that was in the Surface Bump Texture, setting Canvas Bump Scale from 100 to 1 and lowering my bump from 0.6 to 0.02, the matcaps behaved like any other matcap and all was good with the world.
Sign In or Register to comment.