Stack of N-gons: Creating a continuous topology around their edges?

[system]

Hi,

If I have a stack of closely-spaced Ngons, is there a way to “topologize” them so that it forms a solid shape?

The equivalent in 3DS Max is the “terrain” compound object, although it’s problematic with these particular shapes. It can also be achieved by carefully aligning the shapes as splines, and then applying a cross-section modifier, then surface modifier. This is tedious/slow, and prone to errors, so I’m looking for a better way.

Zbrush seems so powerful for remeshing that I can picture it being superior at this kind of task. I’m not a poweruser though and have no idea how to go about this.

Here is the .ztl if you wanna take a look. https://www.dropbox.com/s/vwzrf0bnec83mvx/StackTest.ZTL?dl=0

Screenshot of the shapes in Zbrush. The individual “layers” are not touching each other. All is one mesh.

Example of (roughly) what I’m after. You can see some of the problems that came about from doing it in Max though.

Many thanks for any insight! If Zbrush can’t handle this, please let me know if you know of a piece of software that can. I’m all ears.

[CarterTG]

The first immediate process that comes to mind would be to attempt a Dynamesh procedure in the full version of ZBrush 4R7.

Whenever there are objects that are close enough to each other or outright overlap/intersect (in the same Subtool layer), enabling Dynamesh from the Tools > Geometry palette will combine all those objects into one mesh. Its resolution parameter slider permits setting the dense-ness of the resulting mesh.

When Dynamesh is toggled ON through that palette, you may re-invoke it by CTRL + click-drag in any open spot on the canvas away from the object.

If you don’t get the result you want, undo it (CTRL+Z in Windows) and try it with a higher resolution setting.

If those flat objects have a significant gap that doesn’t cross the merging threshold for Dynamesh, you might try going into Tools > Deformation and play with the Inflate slider to fatten up the objects.

I’m sure the ZBrush ninjas amongst us have two or three additional alternate methods to suggest.

[system]

I’ve tried applying Dynamesh. It appears that with higher resolutions, the layers don’t “merge” as you said, but at 128 they do. The result is rather lumpy, which is partially understandable given the unevenness of the mesh. This was at a resolution of 128, default smoothing. vvv

This is with extra smoothing applied. vvv

This is using claypolish after the first screenshot. It’s creating some holes. vvv

This is Dynamesh again, with a resolution set to 104. Smoother, but with weird “jaggies” along the edges. Edges also have a pinched appearance, and the entire thing shrinks down. I’m looking more for a kind of “skin” around the shape rather than the whole thing getting smaller. However, this is a good start and better than nothing! vvv

Another thing I tried was going in with a standard brush and smoothing everything. This did OK on the flatter surfaces, but for the ridges it pinched them and made them diminish in size.

Any tips for removing the jaggies, especially in the last screenshot?

[dillster]

I would Crease the edges before using Dynamesh, that should help keep things from collapsing. For the jaggies, go to the Deformation palette and try some of the Polish functions.

[zber2]

This is what I got after I reworked it.

Dynamesh > Turn on PFrame to see stray artifacts and delete them > close holes > ZRemesher > Check for and delete more stray artifacts > ZRemesher again > a little smoothing and polishing.

The following is subdivided one time.

[system]

Dynamesh > Turn on PFrame to see stray artifacts and delete them > close holes > ZRemesher > Check for and delete more stray artifacts > ZRemesher again > a little smoothing and polishing.

[HR][/HR]
First off, many thanks for the advice and help making that happen! Looks pretty good. Sorry I wasn’t able to respond sooner.

I got tripped up by the “turn on PFrame to see stray artifacts and delete them” part. I assume you mean turning on polyframe in the UI. I found that if I turned it on and then rotated the model just right in the viewport, I could see little polygons sticking out. I’m trying to mask each so I can delete masked, but as soon as I draw the little mask box over one, it crashes causes me to use up 100% of CPU for about 30 seconds and possibly crash Zbrush. This is for each stray poly! Have a feeling I’m doing something wrong, here.
(OS: Windows 7 64 bit professional, CPU: Intel i7 4.0 GHz, RAM: 32 gigs)

[zber2]

The first thing you do is Dynamesh it. Then after that, you can delete the artifacts. You don’t have to mask each artifact. That would take a long time. Hold down Ctrl+Shift and click on the good part. That will hide it and you will see the artifacts. Now hold down Ctrl+Shift again and drag on the canvas to reverse the selection. Then go to Tool > Geometry > Modify Topology and click “Del Hidden” button. That will delete all the artifacts at once.

[system]

Thank you for that explanation! As you can tell, Zbrush is not my native application.

I managed to go through all the steps after deleting artifacts, and the mesh looked wonky at first. I found that “128” seemed like the best setting for Dynamesh, for any more than that and the layers wouldn’t fuse properly. However, a good Claypolish with “soft” turned to 80 gave me a result I like. Thanks again for the help!

[zber2]

No problem. Looks good.

[system]

Gah, I am doing the exact same thing with the exact same kind of mesh, and for some reason the ctrl+shift+click is not hiding the main shape after dynamesh. Same export method from the same software. I’ve tried it over and over with different combinations of the keys. lI can still mask it by drawing a rectangle. Can’t figure out what went wrong!

[zber2]

Upload the .ZTL to Dropbox and I will have a look at it.

[system]

Here it is. Thanks for offering to take a look, appreciate it!
BTW I tried it again after a reboot, still doesn’t work. Ctrl+shift+click works with the first model, just tried it. Also with one of Zbrush’s default projects. So it’s probably not my software itself…

Here is the new tool: https://www.dropbox.com/s/xkj9kkoy2zf55nl/ProblemHidingMainMesh.ZTL?dl=0 After dynameshing (128 resolution), it looks especially jagged. I ran a “meshintegrity” to try to fix. I went into “modify topology” to see if I could also fix it. I found that if I selected “WeldPoints” or “CloseHoles,” big chunks of geometry disappeared. Going into Zremesher also makes a mess.

Thanks again.

[zber2]

You might not be able to get what you want with this particular mesh. It has some areas that are too thin to work with DynaMesh and DynaMesh does not like thin geometry. If you Dynamesh it and then ZRemesh it, you can Ctrl+Shift+click to hide the main part but, regardless of that, I don’t think you are going to end up with what you want because of the thin geometry. It will be just one problem after another.

Which program are you exporting these meshes from that you are only getting a series of planes and not solid geometry? Do you not have options for export in that program?

[system]

Hey, thanks for taking a look. It’s good to know that mesh thickness is to blame and not some errant Zbrush setting or something. I could redo the stack with thicker shapes.

I’m exporting from 3DS Max. I arrived at the geometry by doing a vector animation, with original shapes derived from fractal software. I used a script to stack each “frame” of the animation in Max, then converted them all to polygons and exported as a .obj with all the default settings. I have tried making a continuous topology natively in Max using NURBS but got a host of problems due to multiple islands, and the requirement of having the same vertex count. Much more tedious than ZBrush!

BTW, the endgame for these is a high-concept urban architecture rendering. Each flat vector is a floor of a floating arcology, but I want them to all be unified with one continuous glass/concrete shape, which is what I’m trying to achieve here in Zbrush. Perhaps I should try sculpting from scratch… (wishing my ZBrush skills were better for the sake of this deadline!)

Ideally even if I have an error-riddled mesh, I could use it as a guide to “trace” by putting it in another polygroup?

[zber2]

I could redo the stack with thicker shapes.

You can get the thickness inside ZBrush.

1. Load your mesh and turn on Edit.

2. Go to “Tool > Subtool > Extract” and set Thickness to .008 then click “Extract” button then “Accept” button. This will add a new subtool called “Extract”.

3. Select the new subtool, clear the mask (Ctrl+drag), and DynaMesh at 128 resolution (default settings). You can delete the first subtool at this point to avoid confusion.

4. ZRemesher at the default settings.

See if that suits your needs.