zbrush & stand-in geo

Daz

jeez why is such a simple thing so goddam absurdly hard?

So the classic method of say, bunching up some skin or cloth around a strap, would be to simply export all of it from 3D app. as obj into Zbrush from the getgo right? Then just periodically hide the strap and paint away on your main object ( or vice versa ). Right? This works out fine. BUT! Lets just say ( as in my case! ) you have worked a ton on an arm or a head in Zbrush, but now later in the day you've decided you have this new geometry ( e.g strap ) that you need to interact with it. Now what?! I cant import the new geo from Maya into zbrush without of course de-activating my current work.
Ggggrrr, anyone got any ideas for a workflow here? I've tried a whole bunch of stuff with mixed results, none of them good. But Im just getting angry now There must be a relatively simple workflow for this.

*edit* I've not really made this clear, but I want to end up with a workflow that enables more than just spitting out insanely high res geo back into maya here. That much I can figure out, but it can only get me through certain situations. I need the subD history too.

Mongrelman

I'm not entirely sure what you mean (it's before noon and I'm a student, ergo the body is awake but the brain ain't).

But what you could try is baking out a displacement map of what you have, then loading in your new geometry and applying the displacement map to that to deform the mesh to where you were before. It would take some faffing around and probably some cleanup, but it might work.

Sort of like how you can turn a bump map into actual geometry (which sometimes yields cleaner results than just doing that geometry in projection master).

arshlevon

i think what you are looking for Daz is multimarkers. someone wrote a pluging called marker master to simplify the whole process. i know this cause i needed to do the same thing, so i asked on the zbrush central forums, but before i got an answer i found a little work around. you can go and try to find a tutorial on markers, and marker master. i think that would be the best bet. but just incase it dosent do what you want i will briefly explan how i got around it.

okay, first auto assign some UVs on your mesh in zbrush. then export a midlevel mesh out, something that accuratly represents the final shape. for this explanation i will just call this a shirt. so next import the mesh(in your case maya) and now that it has UVs create a fairly large texture. also make sure you have your strap in the scene. with the strap and shirt in the same scene paint over the shirt in the area that the strap is on. i am not sure how it works in maya, but in bodypaint i just go into projection mode and paint everything a color and when i hide the strap i have a perfect white strip where the strap was.
okay now back to zbrush. apply the texture, now you have a perfect guide to sculpt around. i masked off the area, ditched the texture and just sculpted the wrinkles, the mask prevented anything that was under the strap fromm deforming.
and there it is. it is actually much quicker to do than explain. after i had that problem i have always made sure to import the straps as well into zbrush.

MoP

Arsh you're like the king of lateral thinking or something. Good tip
I tried Marker Master and it was really weird... I kinda got halfway to getting the result I wanted but like everything in zbrush, the interface and lack of a simple explanation made everything ridiculously complex.

Delaney King

bring on mudbox.

Daz

My God, you are not wrong MoP. I looked into using Markers, even donwloaded the marker master plug-in *and* a video tutorial and *still* it's like pulling your own teeth out. I like your 3D paint suggestion Arsh. I'll have to look into that, thanks.

Jelmer

[ QUOTE ]
bring on mudbox.

[/ QUOTE ]

Agreed, mudbox owns.

Daz

Well, saved by the Russians.

Oddly, rockstars technique didn't work for me when I tried it the other night ( I was getting weird errors from using the reconstruct subdiv command ) but I got it figured out tonight.

Export finished Zbrush arm back into 3D app.
Build new geo around it ( strap, whatever it is ).
Subdivide strap in 3D app. to final subdiv. rez ( leave arm alone of course ).
Export both as one obj back into Zbrush
In Zbrush, show and hide whatever and paint away til the two pieces happily interact.
On completion, do these steps for each piece: For exporting arm, hide strap, delete hidden, reconstruct subdiv ( flaky, but it works. sometimes ) as many times as you need to get back to your original source mesh ( If you even need it that is ).
Export the piece at whatever subdiv. rez you need back into 3d app.
phew, thanks dude.

aesir

I was wondering about the same thing when I had a similar problem. helpful thread

wouldnt it be nice if all the shit we needed was just in one bloody program...

rooster

awesome cheers arsh and daz that should be really useful- one thing Im unsure of, how do you hide the strap? the only way I know is the ctrl-shift drag which hides what you drag over (or the inverse I forget) but how do you select more complex shapes without selecting the wrong geom?

MoP

rooster, use polygroups... somehow... i never got them to work properly but that's the way to go.

poopinmymouth

Easiest way I've found to do polygroups. Planar map each chunk you want to be a group in max. Then move that chunk off the main 0->1 UV square (the heavy black boarder). Put each groups worth of UV's in a different square in the UV editor, as if that main black square was tiled.

Then on import to zbrush, go to polygroups > Uv group. Each squares worth of UV's becomes a group. Pretty simple.

rooster

cheers! sounds like an odd way for them to do it but what the hey

Daz

Also, Im pretty sure that If the seperate meshes weren't combined on export, that If you simply use 'autogroups' under polygroups then it will treat them as such and you'll be able to hide them individually without UV's.

MoP

Ah, useful info Daz, cheers. Thanks for the tip on the UV method too Ben.