ZBrushCentral

Polygon reduction in ZB3???

ZBrush Usage Questions
#1

HI, I was just wondering if there was a quick way of reducing polygons of a hi res model in ZB3.

Notes:

  • I know I could retologise the object with projection and export the object at the level I want. BUT I would rather skip the topology step because it could sometimes take more time retopologising than I would care to bother with. Also, when you have a mesh made of multiple separate objects, projection doesn’t work that well.

  • If I use “unified skin” I lose alot of the detail and there is no guarantee that the number of polygons will be reduced.

  • I could export the mesh and/or subtool pieces and do a polygon reduction in Lightwave but if the polygon count is too high, it can refuse to reduce polygons or just plain crash. Plus, if you have a million plus polygon model, exporting models with such a high count are not fun.

  • I prefer to stick within Zbrush. Oh, and ‘reconstruct subdiv’ doesn’t work on every model, especially if it is a subtool extracted at a high subdiv level. (See, I’ve pretty much thought of everything in regards to this issue :stuck_out_tongue: )

  • I don’t care if the object ends up being all triangle polygons as long as the shape of the mesh is preserved.

So, if anyone with super-genius intellect has some sort of answer, I would like to know. I would also appreciate any tricks that might help in getting a solution, too.

Thanks in advance.

Cheers,
Revanto :stuck_out_tongue:

#2

Does your model just have that one level, or does it have any lower levels at all. You could try locally subdividing the mesh where you want more detail and leave other areas with lower poly counts.

If you don’t have lower levels maybe you can try this. When retopologizing you can use shift click to draw the current topology in the model. Just redraw the topology with shift click and leave some areas blank, and create your own topology in a small area where there isn’t/isn’t gonna be too much detail. Try to arrange some big quads there and I guess traingles if they aren’t a problem. Then connecting it with the rest. Might work :S.

#3

i almost think that even if there was a way you’d choose it to be too time consuming.

#4

I’m no super genius but, if you try that method, you may have what I believe is a memory issue (unless this was resolved in 3.1. Don’t know. waiting for 3.2) I’ve done exactly that and sometimes (not always) it gets to the point where it won’t let you add anymore points. This was on a “‘medium’ high level” mesh. it was mostly the hands and feet that had such a high count. I was attempting to attach them. Let’s face it though, you’ll always have to reach for that other proggy to make certain things happen. Between 3dsmax, anim8or, DeepUv, and the Z, I really can’t complain much.

Also, if you make the brush big enough to cover the model (this also provided that your mesh is not too too high in polys) You can just do ONE click ctrl+shift on the entire mesh and it will fill it.You don’t have to keep dragging it around the model. Then you can edit the parts you want more/less polys on. Careful when doing symmetry though. Don’t assume that what the left is doing the right is doing. I always check both sides to make sure I’m adding or erasing the same on both sides. I’m almost certain that you already know all that but, just incase.

On another note, anim8or can do some poly reduction (says it doesn’t truly support it but tried it once. works.) and it’s free. Look it up on their site or forums. You WILL get tris though. Of course, there’s always the Quadrangulate plugin for 3dsMax to fix that, if you have it. I don’t mind a few tris here and there anyhow. They’re actually useful for certain things like intentional creasing, as well are poles. Btw, gotta add that the “FLATTEN” brush eats unwanted poles and tris for din din. At least in the visible sense. Found that out the other day. They just go bye bye. I was amazed after using my old method for so long. blah blah, more babbling. :smiley:

I see you’re a lw user. Been meaning to take a test drive, from all the nice results I’ve been seeing from it.

adios

#5

if your model is all quads, you can try the reconstruct subdivision function one or more times.

#6

Methinks they already tried that…

#7

Yeah I was gonna suggest clicking the entire model by zooming out, but I’ve had zbrush crash when I did it… once. Yeah I know, not enough evidence :D.

But instead I just do 3-4 clicks with a big brush and it gets the job done.

#8

Well, I am basically trying to get the same thing as Qemloss or Polygon Cruncher from other 3d programs. I thought that unified skin would do the trick but you lose too much detail.

I think that Zbrush could be powerful enough to have it’s own efficient polygon reduction tool (with symmetry even!).

Oh, and yeah, I would only be using polygon reduction on a single level subdiv.

I suppose that the only option is to esport out in chunks, reduce each chunk then stich them together. A long process but the only one methinks.

Thanks for your input anyway.

Cheers,
Revanto :stuck_out_tongue:

#9

Revanto: I hope it works out for you, man. I know how frustrating that is. And yeah, some more reduction tools would be nice.

Znub: I thought that too when Z went into code oblivion and just said “aaaaaaaaaa! no… CRASH!” but I’m one of those determined souls who don’t take no for an answer and so, tried again with a lower poly model. Boom. Worked. Saving constantly at different stages always helps when trying to see how far you can go too, I guess. One model for me typically has about 10 copies. All with different names, of course. As a result, I think I’m going to have to go ahead and get that other 200gig harddrive. :rolleyes:

#10

i think the issue is this, automated poly reduction like you are talking about is messy. Its one thing to make a messy mesh and do your sculpting but if you plan on using it in a production environment you either need to do something at the beginning or retopologize at the end. I think what you want is a fix all button for your weak planning, and if you don’t want to plan then you need to do the extra work to make that mesh the way you want it, and lower or higher in areas you want by retopologizing is the best and cleanest(efficient) method.

i just reread this “- I don’t care if the object ends up being all triangle polygons as long as the shape of the mesh is preserved.” If this is the case why not just make the most simple shape at low poly either by using another app, zspheres, primatives or retopolgy, then divide it and reapply your detail.

Are these things somewhat labor intensive, yes, until you know how to do them with experience, then its easy as pie. Also sometimes i think people forget the 3d roots, zbrush breaks many conventions and was/is grounbreaking, in some ways things are more difficult but try to remember what it was like just a few years ago, it makes so many things incredibly easy that you have time to work on that more time consuming tasks.

#11

At first that sounded a little harsh, but that’s definitely the right way of thinking, spaceboy. There really is no magic button or program that just does it all for you. It can be a lot of hard work and then again it can become very easy once you’re familiar and comfortable with what you’re doing. There was a discussion here a bit ago about Zbrush’s interface and how bad it was blah blah blah.

Tell you the truth, as much as I like 3dsMax’s results… I hate working with it sometimes and wish that the Z would just be the solve all… But it’s not, and I’m coming to terms with that more so every day. Thinking about the reduction subject more… I’ve seen some of the things that polycrunchers and reducers can do to a mesh. Alot of the time, it isn’t worth it because you end up having to fix pieces of it anyway. So, in reality, it might just become more work for you than you had anticipated. Just some food for thought, whilst considering it.

#12

Don’t forget that ‘reconstruct subdivision’ stops to work once the first triangle has been created. That’s the end of that road right there. In some cases I help myself in project paint parts onto a nicely subdivided plane. But that is not a perfect solution either. There is just no way around a good base mesh. If the basic mesh is messed up, then all is lost.
Good Luck
Rainer

#13

It’s true. I can do things that way but I would like to use the tools within Zbrush to achieve this. For example, I could create a basic sphere, sculpt a basic form then extract, say, a nose shape from the form. You can’t really do that with other 3d programs. My major issue is that when you do a mesh extraction, you are reliant on a high density mesh when extracting to get the result you want. You can’t just get a low res mesh and extract a detailed shape from it because it’s restricted to polygon density.

Also, if I try to project a subdivided low res mesh on two subtools (whether they are merged or not), there is a large possibility of errors in the projection due to overlapping polygon information. Mesh projection works best is there is only ONE mesh to project onto.

As a 3d artist (OK, a 3d ‘guy who tinkers in 3d’, actually) it’s not about remembering the basics but finding new and innovative ways to speed up modelling and make it easier to get a good solid form with as less stress as possible.

Don’t worry, I’ve had my share of doing things point-by-point. I just like it when there is an easier way to get things done. It’s just human nature to want things easier in our lives.

Revanto :stuck_out_tongue:

#14
  1. wrong.
    you can make a low level extraction if your target mesh is at its lowest level, then once you’ve done that, divide and use projectall in the subtool menu. its super easy.
    2.and yes when you use any projection as you’re saying over multiple subtools you get that issue, so why not just do one at a time with project all(you don’t have to be in retop mode or anything). once again super easy, super fast, literally you can do the whole thing in less than two minutes and if you store a morph target before hand then you can paint out any areas that are messy(or as i like to do paint in the new clean areas which is easier). I use these methods all the time and they are the least painless way of poly reduction that results in a manageable base mesh.
    i think you just don’t know zbrush enough and are not comfortable or knowledgeable about all the options available to you.
    sorry if this sounds harsh, i just think with all the time you’ve spent replying in this thread you could’ve been done by now with lowering your poly count. good luck to you.
#15

Yes, you can extract from a low level mesh but it is reliant on the resolution of that mesh. However, if you want the shape you want then you need a higher res mesh because you need to mask the shape right. So, if you want an intricate or more correctly shaped mask, you need to up the poly resolution.

But since you brought it up, I just got a great idea. I will have do things from another 3d program, though. I won’t go into detail about my idea cos it’s still just in my head and it might not work.

I am in fact referring to ‘project all’ as well. Have you tried ‘project all’ with multiple overlapping subtools? You will come across those issues I mentioned.

I’m no expert on Zbrush but I’m no moron either. I also know my options, too, so don’t think I haven’t tried them. This is basically one of those experiments that may lead somewhere good. Perhaps a way of helping me speed up my work, actually.

I find your last comment unnecessary. I would appreciate it if you just stuck to the subject at hand.

Thank you.

Revanto :stuck_out_tongue: