Z Brush being rebellious again. Help!

pangarang

1) Sculpted this mesh but didn't like how his arms got in the way of trying to sculpt his sides. So I exported the lowest level as an obj and edited in Maya.

2) Did a few proportional tweaks and raised his arms into a T-pose easier to work with. Time to go back into Zbrush!!

3) Zbrush says: "Yeeeaaaah ... no."

Am I screwed? Do I have to resculpt the higher res-details on this new pose?

CheeseOnToast

I'm not totally sure what's going on here. Usually if the vert order gets screwed up through exports/imports you get a much messier mesh than this.

Anyway, you could use transpose to make your edits rather than exporting to Maya, although this doesn't get to the root of the problem above.

Tom Ellis

This is a new feature of ZBrush 4, it gives your sculpt funky, 'second-skin' armor automatically upon import, surely you've seen everyone else doing it?

Obviously I'm joking.

What were your exact steps for exporting/importing the mesh... it's usually somewhere in those steps that this happens.

xXm0RpH3usXx

just an idea, though i'm not fluent in zbrush, but doesnt it have the transpose master just for this kind of stuff?

maze

what about reprojecting the detail onto your new mesh after some sub-d in zb? although you might have to deal with proportions/posing in zb to make it fit...and this might defeat the purpose....I will recomend to stay within zbrush for this tasks and use the move tool for it.

cryrid

I'd say transpose like everyone else. I think when you import a new obj and transfer the detail like that, it's looking for the model to be in the same spot/pose. Perhaps GoZ would behave differently and actually take into account the limbs being moved?

CheeseOnToast

cryrid, that's not actually correct. As long as the vertex order remains intact, you can make major changes to position and pose outside of Zbrush - something I've done many times. Using GoZ is a more reliable method than manually exporting/importing, but in this case a simple transpose would be far easier.

Ruz

I think whats happened it is the mesh has actually moved slightly. could be a pivot point issue. Sometimes even in zbrush if you move the model around, some parts of it get stuck in the same world space.
normally the vert order thing means the whole model is messed up, not just bits of it
and also in zbrush 4 if the vert order has changed zbrush attemts to fix it automatically ie it reorders the verts

cryrid

cryrid, that's not actually correct. As long as the vertex order remains intact, you can make major changes to position and pose outside of Zbrush - something I've done many times.

I just tried it. Didn't change the vertex order, just exported, rotated, and imported

CheeseOnToast

Just did the same thing, but using Silo instead of maya and it was fine. When exporting out of Zbrush, I usually switch off the "grp" and "mrg" buttons. Silo has NO export options for OBJs, but reliably preserves the vert order. Somewhere along the line something's getting scrambled between Maya and Zbrush by the looks of it. Have you tried it using GoZ yet?

pangarang

WHOA!! Thank you all so much for the replies!

@cheeseontoast - reason I decided not to use transpose was because I find it extremely counter-intuitive. I've played around with it for quite some time now but I still find the results it gives very unpredictable. When exporting the mesh (as obj) however, I did not switch off "grp" and "mrg" instead opting for the default. I also have not tried using GoZ which is something i have to look into. Thanks for bringing it up.

@creationtwentytwo - I took the ztl, lowered it to level 1 detail and clicked export. Didn't mess with any settings. After tweaking the obj in Maya, I loaded up the original ztl, lowered it to level 1 again, and imported the new obj. A warning came up saying "topology has changed, preserve high res details?" and I said "YES". Those are the steps in as much detail off the top of my head. I'm sure there must be some other settings I have to change before exporting, or maybe when re-importing. I'm really not sure :S

Ruz: One thing I am sure of is that the model was not moved when imported into Maya, so my next guess is vertex order might have something to do with it. Problem is the concept of vert order is new to me. Is that another way of saying "mesh flow", like where the 6/5/4/3 star verts are located in relation to each other?

CheeseOnToast - your responses have given me some hope here. What do the "grp" and "mrg" buttons do? Whatever they do, is there a possibility that I can do the same in Maya, now that the obj is already exported from Zbrush (aka too late)?

CheeseOnToast

The fact that you're getting the topology warning tells me that the vert order IS being changed. It's likely the import/export settings in maya you'll need to adjust. Try setting the OBJ import/export like this :




Basically, vertices are each assigned a number (you can show these numbers in Maya with the custom polygon display options). If these numbers change then the vertex order has changed, causing the problems when you import back into zbrush. Zbrush will *try* to fix any errors, but if you've made a significant pose change for example, it'll usually fail.

cryrid

I was using Softimage, not Maya. I don't see any options that would cause the vert order to be changed.

Edit:

When exporting out of Zbrush, I usually switch off the "grp" and "mrg" buttons.

Actually this seems to fix everything.

pangarang

YES! CheeseOnToast you are correct! and your solution solved my problems. Only issue is the mesh that I originally exported and reposed was not done so with your method. So I had to re-export the mesh from z-brush using your method, and match up with my re-posed mesh VERT-BY-VERT. A very painful task but after 3 days it was finally done, lol. Imported back into Zbrush no problem. This is one mistake i will never make again, that's for sure.