ZBrushCentral

Can't Zremesh, Decimate or project large model

ZBrush Usage Questions
#1

working on a this self motivated first time animal sculpt. can’t seem to zremesh without polys that are faceted upon Subdividing, can’t preprocess for decimation without hang or crash.

tried deleting lower sub divisions, and freezing. no layers being used.

only thing i can do dynamesh with slider all the way to the right, but then the main model is still too big to project details. when hit project. zbrush quits.

any help or suggestions how to manage such a large model ?
Screenshot_11.jpgsee image for point count and details.

Attachments

Screenshot_11.jpg

#2

Have you tried " fix geometry"? Are you using ZRemesher guides or color groups?
you could split the model into a couple parts…

#3

If I read the point count correctly and it indicates an active subtool in excess of 40 million polygons, this is simply far too large for zbrush to work comfortably with for its more advanced operations. You must drastically reduce the geometry to make it more manageable.

  1. Nothing in that pic looks like a mesh that should require that kind of mesh resolution. Consider simply eliminating the highest level of subdivision, which should reduce it to something just over ten million, a much more practical number.

  2. If you lose an unacceptable amount of detail doing that, you’ll have to remesh it to be more efficient. At 40+ million polygons, it would be too dense for Zremesher to work on it, so you’ll have to duplicate the subtool, reduce the duplicate to the lowest level of subdivision that accurately captures the form, delete all other subdivision, and Zremesh it. Note that during the Zremesh process there are options to deliver more geometry to areas where you need more detail…optimizing the mesh so that such high levels of subdivision may not be necessary. Please read the documentation for Zremesher.

  3. Once you have the duplicate remeshed, subdivide the duplicate to a more sensible limit–say between 8 and 12 million polygons max-- you can hopefully use the Tool > Subtool > Projection to project the detail from the original back onto it, although the extreme polycount of the original subtool may make this slow or impossible. Please read the documentation on Projection.

  4. Once you restore the detail onto the duplicate, check the results. If you feel you’ve lost too much due to the lower polyresolution, and mesh optimization didn’t solve this issue, you may need to make use of Zbrush’s HD geometry feature to put in fine surface detail that doesnt involve skyrocketing the polycount. Please read the documentation for HD geometry.

In the future, try to aim for a per subtool polycount max of between 8-16 million polys. Zbrush can go higher, but depending on your system, it will become increasingly unstable and certain operations may fail to work. The “practical” maximum per tool polycount will vary by system.

#4

thank you for the replies. if you mean “check mesh integrity”, it “passes”

but i do think somewhere in the process i hit “divide” too much to visually get acceptable detail in the fine Alpha skin pore and wrinkle work.

i’ve currently got 7 subdivision levels and dropping even one level shows obvious faceting in the wrinkles made with alphas.

will add that i was able only dynmesh the high poly with dynamesh at full setting, but still lost most my detail in the face wrinkles, which i thought
i could “project all” back with high poly model, but instant crash in doing so.

might have to simply take an acceptable loss in the detail work and start over there, guess i’ll lose the polypaint too. was not that happy with the color painting anyway so not that big of a deal.

am thinking of doing the color textures in Quixel Suite.

before all this, i’ll try Scott’s suggestions.

thanks again guys for being helpful

#5

Im going to guess here that you did this much detail on the entire gorilla, that would explain the polycount…
Im not going to add anything more helpful than what Spyndel said, but I will add this:
ITS FRIGIN AWESOME!
I want to see you finish this with all of its detail.

#6

see screen shots here :

https://www.dropbox.com/sh/6ha29dehnazy1pa/AADmfSIjyoi_PFtsl8I70m3Za?dl=0

screenshot 1 ) shows what scott recommended about deleting highest subdivision. this did bring it down from 50mil to 13mil. acceptable detail but fine wrinkles got blurry. might have to reapply.

screenshot 2 ) show model duplicated at zremeshed settings

screenshot 3 ) shows issue of not being able to subdivide zremeshed model. when i subdivide even 4 times, it stayed very faceted. not smoothing at all.

screenshot 4 ) so then instead of zremesh first, i tried dynmesh for slider at full right, then did zremesh at full slider right. it still won’t divide smooth but…

screenshot 5 ) is based on previous step mentioned, but now i’ve tried and got a “project all” but a great amount of detail is lost due to the lower model unable to divide properly5b.jpg4b.jpg3b.jpg2b.jpg1b.jpg

Attachments

1b.jpg

2b.jpg

3b.jpg

4b.jpg

5b.jpg

#7

What is your projection distance set to?

#8

Regarding screenshot #3 that shows the issue of the subtool not smoothing when subdivided: It appears as if Subdivide Smooth Modifier (the SMT button next to the “divide” button in Tool > Geometry) is not active. This must be active to apply smoothing when subdivided.

Make sure to read the following documentation on transferring detail in Zbrush:

http://docs.pixologic.com/user-guide/3d-modeling/topology/zremesher/transferring-detail/

You must sometimes increase the value of the .dist slider to get the results you want.

#9

ok , so SMT button helped for sure.

in this screen shot you can see my Projection Distance setting and the low poly is Subdivided 4 times to 6 mil points. When i project, still a ton of detail lost.

// Screen shot 2a.jpg ) before projection of high poly 6 mil points. divided 6 times.

// Screen shot 2b.jpg ) after projection

// Screen shot 2c.jpg ) increased the Projection Distance.

Want to bring back Wrinkle skin detail, what should i do ? Research the HD Geo as you previously mentioned ?

The whole point of projection to the low poly is to take to another program for fast Geo preview and render correct ? ie: keyshot ?

2a.jpg

2b.jpg

2c.jpg

Attachments

2a.jpg

2b.jpg

2c.jpg

#10

The point of projection is to transfer detail from one model, to a model with entirely different topology. This has all sorts of applications in modeling and texturing. In your case it theoretically gives you a chance to transfer that detail to a more efficiently optimized mesh that might give you a chance to redistribute polygons where needed. Areas with more polygons at low resolution will be able to hold more detail when fully subdivided, and areas that don’t need a lot of detail can have their polygons reduced to save polycount for areas that do.

You don’t need to do this if simply deleting the highest level of subdivision of your original model gave you satisfactory results. That mesh polycount should now be small enough to work with more easily in zbrush.

If it doesn’t give you satisfactory results, and you are unable to optimize the mesh sufficiently to hold the detail you want, then yes for fine surface detail it would probably be better to work with HD GEO rather than quadruple your total polycount again. Remember, every time you hit the divide button your polycount is multiplied by four, which is a big deal if the model is already over 10 million polygons.

If all you wanted to do was export a normal or displacement map for the high resolution geometry, you could probably get away with a pretty high polycount. But you said you wanted to decimate or Zremesh the model, and those operations will choke on a mesh if it is too dense.

#11

thank god for awsome people who like to help like mr. scott.

your rock sir ! gonna study up on some better texturing in Quixel. then i’ll probably be back with more questions :wink:

#12

thanks to mr scott,

was digging around about HD Geo and came across this zbrush tutorial on HD Geo.

this explains why my polypaint is all blurry and not holding up the details in texture and alphas of fine wrinkles.

will have to try a totally new paint over of poly paint i guess. since the other one was done on Non HD Geo i guess it’s useless ??

#13

hey there guys,

so i started messing with HD Geo today. from the screen shot you can see HD Geo activated and it took my 12 mil active points to like 24 mil.

have got 8k UV’s applied, not sure if that has anything to do with why i am getting “jaggy” skin alpha on geo ???

any thoughts on this ?? Screenshot_2.jpg

Attachments

Screenshot_2.jpg