PolyGroups and Material/PolyPaint leakage.

[MealeaYing]

@BetaChannel:
I am actually doing exactly what Zber described below as the correct way of doing this, I make my polygroups at the lowest (actualy when there are none) subdivision level. Once I am done doing that, I add as many subdivisions as I can and begin changing the materials (or polypainting, or both), I make it as high as possible because it’s such a visible problem I can’t render things without it being obvious like the example above.
At the bottom is a video, I dont know how to make it go slower, and it’s so fast it’s nearly impossible to see what’s happening…

@Zber:
You described what Im doing and Im doing it correctly.
Using Fill Object (material or color) or PolyPainting both still come out like what you see above.
I make my polygroups when there are no subdivisions at all in many cases, but I always have this leaking problem. I have it even if I do filling with no subdivisions, or if there were and I deleted them. So far nothing works, and since this is the only way I know of to get my polygroups useable in KeyShot Im sort of screwed.

Here’s the video, it’s fast and hard to watch and Im sorry for that.
https://dl.dropboxusercontent.com/u/76310757/ZbrushStuff/Video/BadMaterialNoFun.mpg

Thanks you guys, if you figure this out I will be absolutely thrilled!

[zber2]

OK, I checked further and it seems to be a problem when using MatCap materials. It doesn’t do it when using Standard Materials. I tried different things trying to get it to work with MatCaps, but no joy.

[MealeaYing]

ZBer, I was JUST trying this when it occurred to me to check in here.
Actually though Im still getting the same result

[MealeaYing]

In fact if anything it’s worse.
Masking does nothing at all, and I dont have any way of doing this “right” as far as I can tell, but something’s wrong…

[MealeaYing]

Ok so hiding polygroups does not work, masking doesn’t work, and this problem affects matcaps and standard materials.
So…
What’s left?

[zber2]

This is the result I get using Standard Materials. It’s not a 100%, but the bleeding is very minor. You will get a slight bit of bleeding across polygroups, that’s inevitable, but the higher the mesh resolution, the less noticeable it is. The image below has 6 subdivision levels. Regardless of that though, it’s still crappy when using MatCaps.

[MealeaYing]

Weird ZBer, Im getting nothing like that.

[zber2]

You are right, it does do it with Standard Materials as well if you use a different material for each group. I was using the same material for all groups. However, when you do a Groups Split, then fill when they are separate subtools, you can fill with different materials and you won’t get any bleeding. I don’t know how that would translate over to Keyshot because I don’t have Keyshot.

[MealeaYing]

Yep, thats exactly what Im doing, I have to use a different material for each group so that KeyShot can put different materials on each group, and the problem is the same there as it is in ZBrush, but more pronounced because the renders are sharper and because KeyShot can’t handle anything like the polycount ZBrush can so everything has to be a lower resolution.
Maybe is KeyShot could see polygroups without having to do this life would be better, but as near as I can tell it can’t.
Another problem is that ZBrush can only have about 1024 (or maybe 1000) subtools, I frequently have a lot more polygroups than that and thats another thing, even if this wasn’t a problem with the materials leaking from one polygroup to another, I still cant fix it with that method.
Even in most of my smaller stuff I have hundreds of polygroups, things made using ZModeler are an extreme example of this, though all that GroupLoop stuff was out there too, I have no idea how many there are but it’s usually WAY more than 1024.
Here’s where it turns nasty:
If I split groups they now all have gaps because everything de-welds, so if I subdivide I make big ugly holes, if I try to move things in KeyShot they are in a bazillion pieces and trying to move them all at once is… problematic at best. If I put it all back together and weld, the bleeding comes back as bad or worse than before.

[MealeaYing]

I did sort of find a trick based on your idea, what I can do is if I have less than a thousand polygroups, I can subdivide, then split them, then figure out all the ones that can be merged, and apply materials. This is a nightmare but it can work, I just end up with a lot of subtools and that is very hard to manage.
Its not elegant, but it can work.

[zber2]

so if I subdivide I make big ugly holes
Yes, you have to decide that you won’t be subdividing anymore before you do a split. Creasing might help a bit there though.

I can subdivide, then split them, then figure out all the ones that can be merged, and apply materials
You just have to figure out a workflow that would accommodate you best. I think this is the only way around the bleeding problem right now though. Hopefully it will be fixed in version 5.

[MealeaYing]

Version 5 has me twitterpated!
I can’t wait. And Im going to need more memory. LOTS MORE.

And yah, I suppose thats what I have to do and just live with the idea that most of what I have made in the past isn’t getting into KeyShot anytime soon, at least not the way I want it to.
This also means Im going to stop using ZModeler because that makes a lot of polygroups too and while I like ZModeler it’s causing problems like this and that sucks. Actually Im not sure how Im going to deal with this, its a problem.

GRIN!

[zber2]

The ZBrush elves must be really hard at work on version 5. Haven’t heard anything about it in a long time. It’s got to be getting close.

[system]

Wow I just faced the exact same problem and I’ve just started learning Zbrush! And this is was my first ever material paint!
The Matcap will leak to a large fraction of border polys of hidden groups! Magic.
Did you submit a support ticket for this bug? I am not sure that Pixologic boss reading this thread is going to fix this in V5 without an official bug report.

[MealeaYing]

@ Zber:
They NEVER STOP!
That’s why I love this blasted software more than eating or sleeping!

@ I Make Stuff:
That’s actually a very good idea, it’s an old problem and I will do that first thing tomorrow morning, I hate bugging them, but they hate bugs and this seems like one to me.
Thanks for the suggestion!

[system]

Thank YOU for saving me hours of confusion! By the way I have used zbrush for only a few days but I met several old bugs like these. Several key technologies like dynamesh and zremesher among others are dumped into this program without any regard to a coherent software design. It is basically a mess and needs a complete overhaul. I hope they prove me wrong but I don’t think they will fix this fundamentally in version 5. It is like photoshop, which uses some key technologies but is a very badly designed piece of software.
Dumping technology into an app is not proper software development. I think v5 will be announced in next summit and if it doesn’t bring that much needed overhaul then it never will, ever.

[MealeaYing]

|I think, from direct personal experience, that you need a wee bit more than a few days to get used to how Pixologic is doing things and why.
|
Part of what you are running into I suspect is a lack of workflow which you sort of need some time to develop.
Most people starting off with ZBrush run into a number of problems stemming from the fact that ZBrush is not like other software, 3D or otherwise, this notion is born out by this:
On a 32bit computer, using well under 4GB of ram you can still sculpt billions of polygons and using 2.5D you can work with FAR MORE.
In ZBrush all objects are tools, and this causes confusion, they are not merely objects, all the things you normally think of as tools are simply ways of MAKING tools, Dynamesh is a good example of that. Dynamesh is just one of a great many ways of making a tool.
If you want an example of what I mean by this you can do a very simple thing:

1. Make a dynamesh blob with some interesting shape to it.
2. Turn off EDIT.
3. On the left, second large Icon down Likely says Drag Rect, change this to Dots.
4. Draw on the canvas. Your blob is now a brush (Welcome to 2.5D).
5. Scribble a lot and make something new on the canvas.
6. Now in the Alpha Pallet, also on the left hit the GrabDoc button. Your scribble is now an alpha which you can use as a brush in 2D, 2.5D and 3D.
7. Type Control N on the Keyboard, this should clear the canvas.
8. Put the Stroke Pallet back to Drag Rect and drag out your dynamesh blob onto the canvas again.
9. Turn on Edit Mode.
10. Set the brush in the upper left to Standard and set your Alpha Pallet to the Alpha you just made.
11. Now draw on your Dynamesh blob.

See what I mean?
That is a simple workflow.
You could have also merely done GrabDoc while your blob was still 3D and done the same thing but you would have learned less.
You could also turn your blob into an insert mesh and blown your mind on how insanely cool THAT is.
You could have gone even further and turned it into an array mesh, or a micromesh, or screwed around with your blob until you have a complex robot that is not only suitable for rendering but could be used to trash Tokyo as it hunts for Godzilla in a movie or a video game or both.
You could 3D print it.
If you get good, you could design it around a few microprocessors, some servos, and a battery and THEN 3D print it, see where I’m going with this?
I’m totally serious. and I haven’t even scratched the surface.

Some things, while they seem strange and a bit deranged now, will become clear later. There is a tipping point where all of a sudden you start to see not just what you are doing but a number of other ways to do it (You will find yourself thinking, “AHHA!!! THAT’S how this works!”). It might take a while, but it will happen. ZBrush is not just a 3D program, it’s a LOT more than that.

There are things that drive me nuts, mostly because I suck at them (FiberMesh for Hair), don’t understand how I’m supposed to use them (Vector Displacements), or because I used Sculptris first (thats a biggy). If you don’t like DynaMesh, have a look at Sculptris and see where it came from, it’s not the same thing at all, but in its way it’s just as good. If, after you try that try sculpting in Blender and try not to drink the kool aid after that miserable experience, it’s another world and while some people excel at it I have NO CLUE how.

|

[system]

Ah I see! Excellent points very thought provoking post. I am starting to understand the points you touched on. So let’s see what I have been doing yesterday. I pick zsphere, make a skeleton, make a mesh out of it, turn it into dynamesh, sculpt it with standard, move and clay buildup brushes, use polygroups, masking and transpose like crazy, refine the sculpt with polish dam standard and also a bit of inflate brush, retopo, project the lowres, subdivide to 1 million or so, refine and polish and relax, later will use masking and groups to put surface detail and paint. Bellow are some noob examples of first tries rendered in keyshot or zbrush. Notice the material blur on the wheel! Another work flow could be to just go from dynamesh to decimation for hard surface modeling. Another one, ummm make crazy mechanical objects just using alpha and radial symmetry in shadow box. Or then zproject the crazy pattern on a model and turn it into a crazy armor! Or turn alphas to 3d directly! Snapshot model, grab alpha and then make it 3D again! It isn’t hard to pick work flows in zbrush as you yourself layed out sensible work flows. Even with a few days of study I could pick this up because ZB is so simple. Zbrush is a very simple app and it is making the design of complex objects easy, something that a cad system is not meant to do. Cad systems do the opposite. They make the design of simple stuff very difficult or even impossible.
But I see for example that the spacing slider in brush properties is always grayed out!! Such a thing is never tolerated in a cad system. In zbrush they quietly gray out the spacing slider and people just turn to lazy mouse or roll option to get the job done and won’t complain. I see a thread several years old about a fatal crash in noise maker that I experienced during my first few days and the bug is still there! See what I mean? Zbrush is a very simple program, it just carelessly pushes data around, the data isn’t critical as is in a cad system. In a cad system the tolerance is 0.001 mm. Of course it needs a lot of cpu power to calculate that and the system could be very unstable because it is constantly solving high degree equations and that is expected. ZB does use some exclusive algorithms, but that’s about it. Everything else is left alone. You are right, the possibilities for creativity is endless but that is more a result of the loose sandbox nature of zbrush, and it is meant to be that way and I admit it is a good thing too but that doesn’t mean the user should be forced to tolerate weak or outright silly execution like we see in softwares like photoshop for example. As I said zbrush seems to me or at least compared with those monster cad systems like a very simple sandbox style software. Quite childish even. It also seems to be quite large for what it is! The installer shouldn’t be over a couple hundred megabytes.
Endless possibilities is a good thing but it makes developing a specific and sensible style even harder. My problem is not exactly developing work flow, it just takes me a few days to watch tutorials and read the documentation, and listen to experienced users like yourself, and I am quite a dumb person even. Chaotic experimentation is a good start but I hope to develop a coherent and orderly style in the end. It could be some kind of limitation on my part.
I did try sculptris for a few minutes but it felt like drinking water with a spoon.

[MealeaYing]

It looks to me from those examples that you are doing just fine.
I’m glad you find ZBrush simple, that should make life easy for you, I found it a bit difficult at first, but sticking with it paid off and then some.
Definitely keep at it!

[system]

Thanks for the encouragement. Actually I do have some years of industrial design experience with Alias AutoStudio and autodesk inventor so compared to nurbs modeling this is very simple. I definitely find zbrush a fantastic tool.
Cheers