ZBrushCentral

How to create Low poly for subtool merged model

ZBrush Usage Questions
#1

Hi

I need to create a displacement map for a model which was merged using the make one mesh plugin. Total polygons go upto 12- 15 millions.

No uv problem as no texturing required, please can any body tell me how to lower the subdivision level of the merged tool so that it can be exported as low poly .object with Displacement map.

I do not want to recreate topology as thats time consuming and I just require to upload a low poly mesh of character with normal or displacement map.

please help, Aurick, Marcus or anyone

#2

Guys any help here ?

I just have to provide a low poly mesh which I used for illustration in photoshop. 15 million poly mesh is too big to upload.

#3

I think you’re left with two choices. Re-do the topology on top of the
15mil mesh, OR go back to your tool before you made it one mesh and
set all the sub-d levels to the same number (if your top one is 8, set
them all to 8…or delete a higher level down to the lowest…your choice).
Once they’re all the same sub-d levels, make1mesh again. When that’s done,
enable UV’s in the Tool->Texture subpalette, and ‘re-construct subdiv’ in
the Tool->Geometry subpalette.

It’s a big hole in this subtool workflow (at least I find it is for me) having all
of these 2-3 million sculpted subtools only to find it quite difficult to get them
‘as one’ for production enviro in other packages. Takes more planning up front
than just doing this artistic ‘flow’ of extracting things off and sculpting them.

Maybe someone else has better advice/workflow for you (and me) tho…

Good luck! :wink:

WailingMonkey

#4

Thanks Buddy.

I think I got a workflow from your reply.

Save high resolution model with another name.

Create displacement map from first mode after merging.l.

In the second model bring down every subtool to low 2nd subdivision level and delete the upper levels.

merging the subtools

Apply the displacement map on this 2nd low poly tool.

Will this work without applying morph?

I do not need any uvs now, so that wont be a problem.

Just need to upload a low poly object file.

#5

about your workflow…not sure…you’ll have to test it yourself.

I just did a quick test to make sure I wasn’t smokin’ crack and this works:

The top ‘arms’ are sub-divided to level 4, the bottom are level 1. I took
1 arm at sub-d 4 that had UVs on it, cloned it, then added the clone as
a subtool. Both arms were then set to level 4 sub-d. I selected the ‘parent’
(uppermost in subtool tree) arm as active, then “made-1-mesh” with
GameMaster’s zplug. Since I already had UVs on the arm(s), all I had to do
was re-construct sub-divisions and got both back down to level 1 sub-d.
Zbrush doesn’t like triangles when trying to re-construct (won’t do it). Also,
in a quick test with polymeshed sphere and star, the ‘make1mesh’-ed
objects could not be re-constructed…perhaps because they needed to have
UVs enabled prior to make1mesh.

Anyhow, that’s all for now. Hope it works for you. :slight_smile:

WailingMonkey

#6

Thanks buddy that detail will really help. :smiley:

#7

I’ve tried a more real-world attempt at this (5.5million polys on an ‘object’ made
up of about 8 subtools) today and am sadly dissappointed. :frowning:

It doesn’t want to re-construct at all. I’ve made sure the enableUV button
was on (disabled, then re-enabled and still doesn’t work)…just does nothing, goes nowhere.

I’ve tried with all parts down 1 sub-division level just in case it was too heavy,
still nothing except the ‘unable to reconstruct’ friggin message.

Took the mesh as an .obj into Z2 and it still won’t re-construct.

I’m at a loss. This particular item is going to need 1 UV map, not 8 seperate
maps. Attempts at changing the topology via a low-poly that gets projected
came out like crap (too many wild polys to spend the day fixing, and since
the morph target is only at the highest sub-d but with no sculpting it’s not a
viable fallback – these are more inorganic parts than just wrinkly skin or something).

Crap…what is so difficult about dropping all of these down in divisions of 4
that Z can’t figure out how to re-construct? Aaaack…major frustration! :evil: :evil: :evil:

(sorry for muddying up your thread, wckedsunny, but I’m frickin pissed at this
bullsh*t “workflow”)

truly WailingMonkey (my nick couldn’t be more appropriate right now)

#8

well buddy

its weekend, let Aurick or Marcus come on monday and reply to this post, only then can help us now :slight_smile:

#9

I tried something else.

Here is a screenshot

I will try this on a high polygon subtool to see how convineant it is.

[insert-subtools-options.jpg](javascript:zb_insimg(‘77218’,‘insert-subtools-options.jpg’,1,0))

#10

As expected the zbrush crashed with 10 million polygon model with the above method.

I am trying this method because when I use make one mesh plugin, I am not retaining the subdivision levels like I do with this method and I double checked that every subtool was on same level before trying both of these methods.

I just want a low poly merged model, can any body have better idea ?

#11

so I’ve tried to do it manually (instead of make1mesh plugin) and I can get
only so far in terms of polys.

I have 11 subtools needing to be 1 model (with 1 UV set). The total at hires
is 5.5million. My process was as follows:

  • set all subtools to level 7
  • clone a copy of each subtool (and save it out as it’s own .ztl cause Z3.1 will
    continually crash and I got tired of repeating the same steps)
  • start with a ‘base’ model…in my case it was a belt
  • Tool->Geometry->InsertMesh for each subtool (save a version of the update
    cause Z3.1 will continually crash as you add more polygons/meshes)
  • ‘theoretically’ get to a final single model with all subtools as 1 and all sub-d
    levels accessible

Here’s my final result:

As you can see, the final object is corrupted and has taken a loss in detail of
about 300,000 polygons (actually, I’ve just noticed that 2 additional objects
totaling 300,000 polys have not been added, but I doubt they can be at this
point regardless). This was after an estimated 10-13 crashes where I
would literally do 1 step, save, crash, re-open, 1-step, save, crash…etc.

In attempting to fix the jacked-up belt, I crashed a few more times trying to
‘delete hidden’ and re-import a clean belt.ztl via ‘InsertMesh’. Unfortunatley,
the belt refuses to be added without the result you see above.

At this point I’m going on the assumption that I’m hitting a RAM limit (I’ve got
only 2gigs on my 3.0g PIV XP Pro SP2 machine)

Which brings me to my true frustration and hope that somebody else can
maybe chime in with another solution to this issue. What can be done to take
use of the ability to have many subtools at millions of polys each and then
get them out in a useful fashion for production? I certainly don’t want to have
11 different displacement maps at render time for these objects…

I know of the ‘Binder’ addon for XSI which will take a UV-mapped Hires and
a UV-mapped Lowres and displace from there, but I am currently unable to
create a Hires version of this due to the issues above (either corruption is
the problem, or the inablility to re-construct sub-d levels). Attempting to
project the detail of my Hires via a lowpoly version with Z3.1’s retopo tools
results in unacceptable levels of whackiness as well. Same with trying the
‘ProjectAll’ button on a make1mesh Hires version and my UV-mapped lowpoly
version that’s been sub-divided to the appropriate detail level (sub-d 7 in this
case).

I know Mudbox can do displacement maps from any Hi-resolution model to a
low UV-mapped model. Can Zbrush do the same? What is the best way to
accomplish this given that multiple subtools will most often come into play?
I’m very interested to know if there are other options I’ve overlooked…

WailingMonkey

#12

wailing monkey, thats a very big effort from your side. :wink:

I think we should export high resolution model from zbrush and import it into mudbox for creating displacements maps :slight_smile: lol just kidding.

I am not interested in again spending a hell lot of time learning mudbox now.

Hope Aurick or Marcus will help us out and give some solution.

Man I just need to give a low poly mesh to my client because i cannot upload the high resolution one. As simple as that.

#13

howdy wckedsunny,

yep big effort indeed, and it’s not the first model I’ve needed to group all the
subtools up into 1 mesh and get 1 UV-map from the result. Like I said before,
it seems like a big hole in the advertised ability to work in multi-millions of polys.

I’m wondering if there’s an easier way…aside from having a fixed game-plan before sculpting
starts so that a model is grouped already (but then that takes away the
ability to put in the necessary detail at Hires for each specific subtool, which may
be necessary for texturing purposes). As of now it would seem that I can’t
truly work on anything more than 4+million polys if it has joined subtools
in which the overall model needs to retain it’s subdivision levels (with my 2Gig
RAM, at least).

In regard to you getting your lowpoly…you’ve got a 10mil version that
still has all of the sub-d levels on it’s subtools, right? Why not just take
them all down to lowest sub-d and ‘make1mesh’ on that then export out as an
.obj? Or am I missing something?

WailingMonkey

#14

buddy I need to give the displacement map of that low poly as well :slight_smile:

Maybe I will try this

Use mesh1 plugin to create one mesh of high poly 10 subtool model. Generate a displacement map from it.

Go back to the un merged model and bring down all subtools to subdivision lvl 2.

then merge the low poly into one mesh and use the displacement map created before on it ?

Will that work ? I think I have my doubts.

#15

ahh…I was just thinking you needed to give the lowpoly model (no disp.). :frowning:

I vaguely remember cannedmushrooms might have had a tutorial on getting a
map from a random Hires to a UV-d lowres, but I never saw it (and haven’t
done it myself, so I’m not sure if it can be done). Maybe your hope might work
if there’s a way to do that (you won’t have 1 UV-map on your ‘make1mesh’
and I doubt you’ll be able to create one via GUV or AUV–for that many polys
Z3.1 is almost sure to choke).

Otherwise, I think you’re in the same bind as me with a
Hipoly-no-UV-mapped-no-retained-subdivisions-pretty-but-useless-
outside-of-Z3 model. If it’s not too intricate, you could ‘make1mesh’ at say,
a medium resolution, re-topologize that with retained sub-division levels, go
down to the lowest, export lowest, set up UVs on lowpoly, do the swap with
your non-UV-d lowpoly, ramp back up to highest midresolution, then try to
re-project your 10mil detail.

If all of that works to your satisfaction, you’d have rebuilt the entire thing as
one, retained subdivisions, and applied UVs for a final displacement map
creation/export (and you’ll have your lowpoly with UVs, of course). What fun
this ‘art’ is, no?

Anyhow, good luck…I gotta go now as I’m getting pissy again. :wink:
Let me know how it comes out!

WailingMonkey

#16

Marcus , Aurick

any solution for this ?

#17

bump

#18

BUDDY

I contacted game master who created the one mesh plugin.

He has given link to the EZ version of same plugin created by ez, which when used make all the subtools have same subdivision levels and can be adjusted.

Have a look at it in the make one mesh plugin thread, find my post there.

The problem is when we make one mesh, again all the subdivision level are removed n.

Still maybe this can be used to our advantage, do have a look it.

regards

Sunny

#19

Apologies for the delay, I’ve been thinking about this one. :slight_smile:

I think it likely that you will have problems if you try to combine a bunch of subtools all at their highest subdivision level.

What method you choose will depend on your model, and what you are planning on doing with it. There are a number of possibilities:

  1. You keep the subtools as they are, assigning UVs to each subtools separately, generating displacement maps for each. The separate OBJ are then assembled in your external app and the displacement maps applied.

  2. It may be possible to combine the subtools (that have the same number of levels) at the lowest subdivision level, apply UVs to the combined mesh so that the groups occupy separate UV space and then split into subtools again before exporting each and reimporting into your subtools so that the UV info is imported. It would then be possible to generate a single normal map using ZMapper. This is basically the procedure used in the Maya videos in the ZClassroom and I recommend those to you as a good working method.

  3. I might be possible to use the method in (2) to generate displacement maps that could then be combined but I’m not sure how feasible that would be.

HTH,

#20

Howdy marcus_civis,

Thanks for the reply. :slight_smile:

I’ve come to the conclusion that I’m hoping for more than is physically capable
in the realities of current technology.

The bottom line is the end result. If I want the fidelity of 4 million polygons,
I need to have one 4 million pixel (4096X4096) map. I can’t have an 11 million
polygon model (in 11 subtools) and expect to get that onto a 4096X4096 texture
map (either normal or displacement). It’s just not physically possible.

Additionally, if it’s for a final render (say, standard 720X480), I’ll never even
see that detail until I zoom in to the model at a range that can reasonably
support the translation of the pixels rendered (again, 720X480 pixels isn’t
going to support the fidelity of my 4 million polygon subtool of a shoe or
something).

I’d still like a convenient/easy way to get multiple subtools mapped to one
texture space (after you’ve sculpted them) from within Zbrush (and retain
the ability to keep the high sub-d levels of the sculpts to be used for varying
pixel-levels of texture maps), though. :wink: :stuck_out_tongue:

WailingMonkey