ZBrushCentral

randomly occuring bugs

ZBrush Usage Questions
#1

here are some really annoying bugs i am experiencing

windows 7 64bit
those i experienced in versions lower than 4 also happened in windows xp 32bit, since i am now working on a totally different mashine than back in the 3.x versions i assume hardware is not the problem as aint OS bits or OS

undo hotkey:

is stops working from time to time without reason it seems, i even added those undo hotkey lines to the startuphotkey.txt but it didnt help at all

ZBrush versions: all (since 3.1 tested)
annoyance factor: 10/10
current workaround: restart, use ctrl+y instead :wink:
explanation: ZBrush seems to switch over to the qwertY keyboard setting, i usually use qwertZ tho and hence it seems as if ctrl+z would stop working, indeed it does not, it only becomes ctrl+y on german and french keyboards…

brush Z intensity:

soetimes after switching back to clay buildup (i assume its similiar with other brushes) its adding/substracting alot more Z value than it should and i have to turn down Z to 1 or 2, then seemingly without reason after a few strokes or after switching brush it goes back to normal (could be tablet related but it happens too if i use the mouse and did not happen in versions 3.x afaik hence eliminates the tablet id say)

ZBrush versions: 4R2
annoyance factor: 10/10
current workaround: change brush, paint, swap back to the brush

Z add/sub swap:

its rare but sometimes Z swaps add with sub, meaning it paints positive when im in Zsub mode and vice versa
current workaround: restart

annoyance factor: 5/10
ZBrush versions: all (since 3.1 tested)
workaround: restart or just live with it

negative RGB during Zsub:

sometimes using Zsub while RGB is active it paints a negative rgb value meaning it paints black instead of white, could be intentionally as ive seen it happen in one of the tutorial videos too, think it was that how to sculpt lips video by Ryan Kingslien

annoyance factor: i assume 10/10 if you try to polypaint while sculpting, didnt have that problem yet tho
ZBrush versions: 4R2
workaround: turn off rgb

dynamesh not doing anything:

right now i have a tool at 560k polies for which id like to increase the resolution but all i can do is lower it, increasing it does not do anything at all, i had however another tool with more than 2mil polies yet and dynamesh active and it did not stop working

annoyance factor: 10/10
ZBrush versions: 4R2
workaround: none, even reloading the tool, exporting and reimporting, restarting Zbrush does not help, i could use subDs now but then i couldnt activate dynamesh again or loose all the detail
explanation: dynamesh is hardcoded to only support 1024 polies on each of the three axis, theoretically that could mean around 6mil polies for a cube, much less for elongated shapes tho

mem settings getting reset

happened before i used that UI hotfix available in the ZBrush 4R2 faq, saving the config didnt help and it always reset itself to 256mb upon restart, the ui fix however seems to have helped even tho it was actually for somin else lol

annoyance factor: very high if you didnt realize it did reset like me and wondered why a 2mil poly tool moved choppingly like a 20mil poly tool
ZBrush versions: 4R2
workaround: get the hotfix from the Zbrush 4R2 FAQ (at the very bottom)

#2

Could you elaborate a bit on the dynamesh thing? Hard to tell what you mean from what youve said, but it may not be a bug.

Dynamesh doesn’t update in certain situations if there’s nothing to update(for instance, you’ve just dynameshed, and no verts have changed position.) Make a light brushstroke, and it will remesh again (Or undo to the last remesh, and repeat it until you get the resolution results you want.)

And there’s no reason to lose detail with DM. While it is mainly for shaping form at low to medium resolution, and there is a resolution limit (that varies with the object size in relation to the worldspace, so if you need more rez, consider scaling the object up), theres nothing to prevent you from subdividing to higher resolutions to work on surface detail, then freezing those subdivision levels and having DM reproject the detail afterwards while it remeshes your model at low rez. If you have your form, and are onto high rez surface detail, there’s little point to dynameshing that much any longer, unless you significantly alter your form, or want to redistribute polys periodically.

#3

@dynamesh

i created a human, starting at a low dynamesh resolution of 40 and made my way up to 128 at which point the mesh has about 500k polies,
now id like to start working on more details like eyelids, ears and so on for which id need a tad more polies and frequently need to remesh to get a nice topograhy from all those polies that i pull out of the head,
however when i start raising the resolution to something above 128, wether it be 1024 or 500 or what i actually wanted 160, nothing changes at all, and yes i did make those slight brush strokes to get dynamesh to update
however if i lower the res to 50 or somin i actually get less polies as its supposed to work, increasing res again stops at around 500k polies

due to your tip with the mesh size i just tried resizing it but it still stops around this magical 500k poly barrier, thought it might be hardcoded not go further but since my last dynamesh sculpt had over 2mil that cant be true

it is actually also the only tool in which i experience this problem, did a mesh check which turned out fine, exported and reimported as obj, didnt change, restart, didnt change, every other tool works like a charm :confused:
and i can really not see a difference from this tool to any other i made so far

in case you wanna take a look, this would be the tool (yaya its wip lol) (11mb… packed as *.rar)
http://www.sendspace.com/file/83a4cj

as for detail, if you sculpt at lets say 10mil polies and redynamesh ending up at 500k you loose detail, sure you might be able to reproject (not sure if that works without a clone) but it wouldnt help as the projection detail would be in areas that didnt get a new homogenous topography and hence not get affected by dynamesh making the procedure pointless in this case and much to complicated and tideous anyway and dynameshs great strength is the ease of use and plain awesomeness imo :wink:

honsetly i simply have no idea why it would stop increasing res with this tool, not even speaking of a solution or workaround :frowning:

#4

Well, three things.

  1. The tool you uploaded is an active zsphere tool. I’m not really sure if you can use DM with a Zsphere preview skin, and I’m not sure why you’d want to. They are sort of two competing ways of doing the same thing…quickly establishing form at low to medium resolutions.

  2. You model( or the preview skin, anyway), is past the threshold of when DM is going to be most effective. You have highly accurate form, and are now beginning to work on surface detail. The dividends from DM are going to be minimal at that point. Once you’ve moved on to surface detail, you’re essentially zbrushing as normal. At that point you simply subdivde your model, and sculpt as normal. You may periodically want to remesh your model for relaxing polygons and improving sculpting performance, but unless you’re significantly altering your form, you might find you get better results just using the standard remshing and projection methods in the subtool palette for that. There are downsides to subdivision level freezing process with dynamesh.

  3. I don’t believe there is any hardcoded poly limit with DM, but there is a detail threshold. Past a certain point, it just wont devote any more polygons to a form. If you were to take the snakehook, and really radically alter the form’s complexity to where DM needs more polygons to accurate render it, you’d see a rise on polycount again.

Obivously, a 100-500k mesh (the ballpark DM tends to work best in) wont hold 5 million polygons worth of detail. However, if you ctrl-mousover the “Freeze Subdivision Levels”, you can read the description of that process. If a model has multiple subD levels, Dynamesh will give you the option to freeze those levels. You can then use dynamesh to alter the lowest subd level of the mesh, and then unfreeze them, which will project the higher subdivision levels and detail back. As I said before though, this isnt a casual process. It’s best used for when you want to significantly alter form(give someone an extra arm). Depending on the situation, the traditional remeshing/projection process may sometimes be better to simply redistribute polygons.

To sum up, I dont see any bug here. Just a better understanding of what Dynamesh is, and isnt, is needed. It’s not a tool designed for high level detail, although you can still use it at those high level of detail, on a situational basis.

#5

  1. yup im aware of that, never turned it into a polymesh3d, but i dont see why i would either, that way i have a nice zsphere rig ready yet out of which i can build my final rig later on for posing, and so far i never encountered any problems with it still being a zsphere rig (have some other tools with it still being active), just got to be careful not to hit A before duplicating.
    for the record, i turned it into a polymesh3d to see if dynamesh would kick in again but it didnt

  2. well i wouldnt say im done with the form yet and only have to add pores and such now, then i wouldnt mind, i still have to work out the ears and such things and simple stuff like moving some polies down to form an eyelid yield much better results with dynamesh on, i simply love having a homogenous topology which gives all areas the same detailability (whatta word lol)

that remesh all is something i try to avoid wherever i can as i so far only had trouble with the results, neiter do i really need subDs with dynamesh at all, for realtime use ill simply use deci master and project all for statics (like the crysis 2 guys did i believe) and retopo by hand for things that might get animated or rigged,
sure subD levels are nice if you intend to change the overall shape later on but then i could also use project all on a new low poly cage instead and just keep dynameshing allowing me to keep the overall sculpting polycount roughly 30% down due to the nice topo (just wish DM would allow for masking only retopoing the unmasked areas giving polies where needed only)

  1. just tried that snakehook-to-change-shape thing and still i dont get a higher res with dynamesh, and no, as i mentioned before i had dynameshes with much more polies hence also dont believe there is a limit

the mehod you mentioned to work on a higher subD and using DM in a lower subDs is probably ok to work with but it kinda defeats the easyness i experience when i use DM, just one mouse movement and baam, done, not a bunch of clicks and waiting for reprojection

so to sum it up from my point of view i see a bug here, i just did not find the reason for it yet as no other tool i tried DM on shows this restriction, your method is probably ok as workaround but i assume id still arrive at the final sculpt faser if i started from scratch and let DM do its magic… hoping the (imo) bug does not reoccur

and hey, even if DM was designed for a different or less complex purpose its just too awesome to only let it do the “normal” stuff, would be like using babe ruth as a right fielder with a pinch hitter, rather let the beast loose and win the world series instead :stuck_out_tongue:

so i guess ill just remodel her and learn a bit more about anatomy on the way hehe :wink:

edit:
sexy mech btw :slight_smile:

#6

The documentation is quite clear about there being a detail threshold limit for dynamesh.

On a technical level, the new geometry resolution generated by DynaMesh is limited to a cube of 1024x1024 (≈1.05M polys per face & ≈6.3M polygons per DynaMesh/Subtool). When the mesh bounding box is pushed out of this maximum resolution, the geometry can start lose details.
When you start with a low resolution, a larger model will be allowed before it starts losing details. A higher resolution will allow more small details, but it will be limited in terms of how much you can expand the bounding box size – in other words, how far you can push the surface between remesh operations.

In this item on your list, there is no bug. It’s working as intended. Generally speaking, its for shaping bodies, not pores and wrinkles.

For the record though, I got a skin from your zsphere tool up to 800k polys by increasing the worldspace size and complexity of the form. That was just to prove a point though. For practical purposes, you have to accept you’ve reached your practical limit for detail for that mesh with Dynamesh. It’s time to start zbrushing as normal.

#7

For the record though, I got a skin from your zsphere tool up to 800k polys by increasing the worldspace size and complexity of the form.

that way you still didnt increase its resolution, you just increased the volume needing more polies to cover it

in regards to that tech note, does that mean a subtool may only have 1024 pixols/polies on each of the 3 axis? in my case from head to toe 1024, from bum to bossom 1024 and from left to right hand 1024…
as i understand it atm i could get a higher res if i would change the pose to something more compact, like a person in fetal position for example
6mil total sounds great, with the nice poly distribution that would be totally enough to make a very very neat high poly character… pity you only get that as long as its volume is shaped like a cube… great for busts tho id assume

anyway im spoiled now, i dont wanna zbrush normally again :confused: (hopes for version 5, 64 bit and even more dynameshing)

thx for the help and explanation :slight_smile:

#8

More polygons covering the same surface area=more resolution. Resolution is just another way of saying level of subdivision/poly count. A mesh with more polygons can hold more detail, because it is a higher resolution mesh. Scale is relative.

To a limited extent, ZB will assign more polygons and increased accuracy the larger an object is in the worldspace. You can test this yourself by dynameshing a primitive at max rez slider that you have shrunk in the worldspace to a tiny degree vs one you have scaled larger with the transpose or deformation controls. But there is a limit.

You’re not losing any functionality. Zb gives you many methods for redistributing topology over stretched polygons for sculpting performance. Even if Dynamesh could directly process 5 million polygon meshes, the performance burden would be so great you may as well be using the traditional re-projection tools, as any speed advantage would have been lost.

#9

More polygons covering the same surface area=more resolution.

yes, but you said you increased the complexity of the form which results in a greater surface area (sorry for saying “volume” in my last post), a brain for example has a larger surface area than a football of the same size due to all those wrinkles etc, hence needs more polies of the same size to cover a similiar volume

as for performance, could be, as i mentioned in the first post i witnessed a heavy performance drop vs 4R1 which i thought would be due to the resetting mem slider, but it could be that it was that 2mil poly DM just aswell…

edit: just tried with my gargoyle dude who has 2mil polies and the rock underneath 500k, the gargoyle being a normal tool and the rock being a DM makes it stutter when you turn the model, turning DM off for the 500k rock makes working smoother again,
its weird tho as a “normal” 2mil poly tool shouldnt really affect the performance much in combination with that 500k DM rock tool, yet the performance drop is really noticable in comparision to the “problematic” 500k girls body DM without another 2mil “normal” tool in the same scene, seems that once you have one DM in your scene all tools in your scene become “victim” of that performance drop, maybe even get calculated like a DM too without actually being one… now that could be a bug… maybe :stuck_out_tongue:

as for size in the worldspace, seems to have an affect as you said, making the girls body smaller results in a lower res at the same res slider settings, making it larger however shows no effect probably because those 1024 polies in one direction are achieved yet on the Y axis i assume

and thanks, guess i understand DMs alot better now… alot of the magic suddenly dissappears :frowning:
pets poor Dynamesh on the back… “good boy”

#10

It shouldn’t, except from a particularly myopic point of view. Dynamesh pays huge dividends across the entire spectrum of Zbrush’s modelling ability, making many things far more effective or practical than they were before, and opening many new possibilities in intuitive mesh creation. You’re simply trying to use it in a way it really wasn’t designed for. Frankly, you missed out on a lot of the appeal of Dynamesh by using zspheres to make such a dense skin in the first place.

#11

the skin wasnt that dense, i just used the zsphere rig for the basic shape with adaptive skin set to 1, using zspheres gives you simply more control over that shape than using curvetubes or something, then used DM to gradually go higher, and i do of course still love DM but i really hoped to be able to use it for alot more than a basic shape, and you can, you just cant for every shape, as i said its not my first DM mesh ;), that gargoyle i talked about earlier was a DM all the time until i started with the very skin detail and it worked like a charm, but that was due to its compact shape which never exceeded the 1024 polies on any of the three axis i assume (not really in the mood to count em lol)
believe me if i say i totally worhsip DM… before it i spend a huge chunk of the time just on retopos and all kinds of methods to get geometry where it was needed :slight_smile: (well you still need retopos from time to time but definately not necessarily during WIPs)

#12

undo hotkey:

is stops working from time to time without reason it seems, i even added those undo hotkey lines to the startuphotkey.txt but it didnt help at all

ZBrush versions: all (since 3.1 tested)
annoyance factor: 10/10
current workaround: restart, use ctrl+y instead :wink:
explanation: ZBrush seems to switch over to the qwertY keyboard setting, i usually use qwertZ tho and hence it seems as if ctrl+z would stop working, indeed it does not, it only becomes ctrl+y on german and french keyboards…