ZBrushCentral

Delete Overlapping, Hidden Geometry - No Remesh

ZBrush Usage Questions
#1

I’m coming from effects and animation and decided to dip my toes into modelling. So far it’s been a pleasure, but there is one thing I cannot figure out even after days (no joke) of internet research:

How do you merge multiple subtools so that you get one unitary mesh with NO hidden or overlapping geometry.

Let me give an example:

Let’s say you have a character that has his skin, a shirt on top… and on top of that shirt a coat.

Each is a subtool.

How do I merge the subtools so that I get ONLY the outer skin, with all the hidden geometry deleted?

Some say to dynamesh - BUT this is problematic because even at max setting I get artifacts and lose fine detail.

If I close holes, is there a way to delete everything inside the outer skin?

The only solutions I’ve found online result in artifacts and a loss of detail.

Thank you for any help!

#2

You’re only doing half the process.

If you want to keep just your outer volumes then you’re going to want to use Dynamesh, but you need to duplicate all of your meshes. Merge the duplicates together and dynamesh them. Don’t worry about details, just main forms need to be maintained. After that you’ll want to probably use Zremesher to give you a decent flow. Now take your Zremeshed model and subD it 1 time. Use tool.subtool.project all (make sure all of your high res independent meshes are visible). Now subD your model and project all again. Repeat this process until you get to the detail level you want to maintain.

Clean up any areas that caused artifacts during the projection process.

Hope that helps.

#3

Basically what Beta said; Dynamesh, then ZRemesh (Retopo), then ReProject.

Don’t forget to keep a copy of the originals.

#4

I have attached my screenshots.

Even at the first level - when I project, there are problems.

  1. Original how it should look

  2. My projection - Note the skin showing through and the shirt coming in partial patches.

orig.pngproj1.png

I’m probably missing something but this doesn’t seem to solve the problem as it takes me back to what I’ve tried. Everytime I try to project from overlapping geo onto dynameshed shell I have these issues.

I only works properly from dynamesh to dynamesh… meaning from outer shell to outer shell.

Also, you said not to worry about how close the dymaneshing comes out at first. But there is an issue. For example I get the ear partially stitched to the head, when dynameshing (see below).

clip.png
Reprojecting onto that results in even bigger artifacts.

#5

The ear getting attached is problem, and that is effecting your forms. So you need to increase your dynamesh level to support the forms you want.

From the looks of it you need to adjust your projection distances.

I would delete do a quick masking session and delete all the extra under lying geometry in your mesh as well to help with projections.

Sidenote: That dude’s pecs are way too low.

#6

Thank you for your time and help…

The dynamesh resolution results in the same artifacts, even at the highest resolution (2048).

Were you referring to some projection settings when subtool is dynameshing? I have not seen any settings for projection (except the project button) in the Dynamesh menu.

Or were you referring to the Projection you do after Dynameshing?

I have thought about the mask > delete before but it is an extremely tedious task as even the smallest piece left shows up.

Is there a way to project a subtool as a mask onto another subtool? So for example I could project the shirt as a mask onto the skin and delete (the skin under the shirt). This would be way more accurate - and not to mention sane :slight_smile: as manual masking all these pieces would probably put me in the nuthouse before they’re done…

I tried looking online but all I could find is this thread… http://www.polycount.com/forum/showthread.php?t=97461

I don’t even know if this applies to my situation.

Thank you!

PS: Thank you for the note on the pecs :wink:

#7

If 2048 isnt enough then you have 2 options. Scale your meshes up or clean the errors by hand.

Projection settings are right next to project all.

Do you mind if I ask why youre doing what you’re doing?

#8

Hi

Well, I’ve scaled up the model 7 times then max dynamesh. Still artifacts and loss of detail, albeit now I can zoom in closer and go around them. I’m probably not understanding something about dynamesh I’m guessing.

newclip.png

You said “Projection settings are right next to project all.” - I’m not clear on this. The Project All menu affects when converting to dynamesh?

Here’s why I’m doing what I’m doing…

I need to export this out of Zbrush for either ptexing (which you can’t do in zbrush) or multi uv set texturing in Mari. Baking maps of overlayed geometry results in artifacts. The parts that have no overlayed geo come out good, but anything that has layers of hidden geo underneath comes out with real problems.

I also have a retopo mesh done outside of Zbrush, which I can import, but is subject to the same artifacts.

Maybe I’m missing some key step in this process but I can’t understand where. Feel free to let me know if I’m just not looking correctly at things.

PS: I take it projecting a mask from a subtool onto another is not an option…

PPS: Maybe a way to boolean cut out the parts???

#9

Alright. So I am still lost. Why do you need to project anything in Zbrush? Zbrush has always been prone to artifacts at the intersection of multiple subtools. As for the errors you’re getting on your mesh during dynamesh, I’m not sure what it is that I am looking at there. I’m guessing that is the backside of an ear…but if you already have retopo that you’ve done you don’t need to do any of the steps I mentioned. The only thing you need to do is project your new topology onto the old one, which, as you’ve found out, will give you errors when you have subtools sitting too close to other ones.

What I am saying is, you probably don’t need to do any projections inside of Zbrush as it is going to give you errors that are going to require a bit of clean up.

You shouldn’t have anything in dynamesh turned on, you don’t need to project anything with it…which again, is moot at this point as you already have new topology.

What is the end goal of the whole thing? 3D printing, still images, videogame character, etc?

Bit of a ramble

#10

Thanks so much for putting up with all of my mess.

So if I take overlapping (hidden) Geo out of ZB I have problems with setting it up for either multi UV or ptex. These problems are due to hidden geometry. I know this because anything without hidden geo has no glitches. I can set it up for ptex multiple UV etc… with no problems.

I can’t take it into a normal app like Maya to delete that hidden geo because of the high polygon count.

The final goal is animation.

I was able to Troubleshoot my issue to the following points, but I honestly have no idea WHY this affects and how I could combat it:


  • The head and body were created in different ZB sessions and each saved as .ztl
  • Each has multiple subtools (eg: body has skin, shirt etc…)
  • IF I Dynamesh the body with all it’s subtools = Everything Okay, barely any artifacts if any (details preserved)
  • IF I Dynamesh the head = Everything Okay, barely any artifacts if any (details preserved)

  • IF I combine the body (even if it’s all just one Dynamesh - meaning that I merged and dynameshed all the body subtools) with the head and then try to Dynamesh them together, that’s when the artifacts and loss of detail show up