I am having the worst time trying to figure out why Maya thinks these verts are Non-Manifold.
I am fairly new to modeling as we didn’t cover it for my degree, but looking at Maya’s description of Non-Manifold I do not see how these verts could be NMG.
This is what I see when I do a Cleanup>Select>Non-manifold
The model is attached here.
My sincere apologies if this is baseline, but I am at a wall with this issue as its really slowing down all production.
Solved!
Go to Solution.
Товарищи, как определить где накосячил с моделью? и есть ли способ это сделать не рассматривая детально модель? Может ли майа подсветить как-то проблемную часть? Майка ругается на non-manifold geometry.
Привет. На собственном опыте скажу что найти — иногда — «дырку» сложно….. ну….. будут смеяться гуру……. выход такой …. вырезаеш стремный сегмент…. в обж…. его или в фбх….. потом вставляешь и исправляешь…. если не в лом поменять полностью все. По другому ни как если ты сделал изначально стремную геометрию. Но это исправляется простым знанием геометрии и изонометрии…. школьный курс.
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Товарищи, как определить где накосячил с моделью? и есть ли способ это сделать не рассматривая детально модель? Может ли майа подсветить как-то проблемную часть? Майка ругается на non-manifold geometry.
Попробуй Сглаживание, и обрати внимание на локализацию артефактов… как правило любой косяк в геометрии отразится на виде всей модели и особенно в точке брака сетки..
Go to Maya
Cleanup finding non manifold geometry where there appears to be none
I am rigging a character that I have made, but when I go to skin it, it gives me an error, and says I have non-manifold geometry- odd since I didn’t do anything out of the ordinary while modelling. I went to cleanup and selected only the non manifold geometry option, and it selects a whole bunch of random faces on my mesh. These are just regular quads though, I pulled it apart and could find nothing strange going on in ANY of the «non-manifold» faces.
Is there any way to get maya to show you what exactly is making a face non-manifold? or are you just supposed to guess based on what it selects, even if it selects otherwise completely regular quads?
I have cleared my history and everything and nothing seems to help
it is also worth mentioning that setting the cleanup option to fix the geometry rather than just selecting it does absolutely nothing, and still leaves the geometry the same.
Maya, nonmanifold geometry issues. Solution?
How to ignore errors like: error: line 0: cannot reduce polygonal object with nonmanifold geometry…
Many tools (scripts) doesnt work in maya, cuz of nonmanifold geo.
No such problems with 3ds max, unreal or whatever. They just work with any geo. Unfortunately i have to work on maya. How to go around its limitaitons? Clean up didnt help at all.
For proxy out enviro, i dont need perfect geo to work with, but i need to have flexibility in tools such as mesh reduce.
Replies
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cleanup should find the issue.
could you show us what it does find? -
nothing works properly with non-manifold geometry, max just doesn’t let you create it
cleanup will find usually find your problems — it won’t necessarily fix them properly — usually telling cleanup to select and then manually deleting the problem components will get you there.
Alternatively, one thing that can help is exporting to FBX as that’ll shatter any verts contributing to non-manifold geometry — you’ll end up with a load of unwelded verts but at least the mesh will be valid.
if the geometry is utterly shit you should probably just rebuild it though
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The big issue with Maya is that you can’t delete verts or edges like say in Max or Blender. It only lets you delete in face mode. It makes cleaning the non manifold geo a pain. Maya seems to create bad geo just by selecting it. It seems to do it randomly. You make a boolean for example you get non manifold geo sometimes. Sometimes it works fine, same with quad draw… If you use Maya you just have to spend hours fixing bad geo. To clean bad edges I have to convert the selection to faces then delete.
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I see this sort of complaint fairly often.
While Maya is unforgiving, and frankly a fucking awful modeling tool it is entirely possible to manipulate geometry without generating shite — I do it all the time, as do many others.
If you find yourself having to clean up your own work all the time you need to reassess the way you build things.
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A trick I’ve found to work fairly often is to use mesh cleanup to identify problem vertices. Detach/split those vertices, then weld them again.
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The big issue with Maya is that you can’t….This isn’t true. Or, at least it doesn’t need to be. I have been using Maya for about 1.5 years but after about 6 months of use I was no longer having to work like this. Rarely ever do I touch the cleanup operation tool. If I do have bad geo it is always immediately clear how it was created, and cleanup takes a few seconds… I guarantee you I’m not a particularly smart person. Of course if you learn some other program first coming to a new one will be difficult. I’ll admit the one time I tried out max I lost my patience pretty quick. Compared to what I’m used to with maya, max seems very obscure and overly technical. But that’s just a noobies first impression, so it’s not worth squat.I am not sure what you mean about not being able to delete vertices. You can delete vertices. If regular delete does not work becuase its non-manifold, you use backspace delete. I think thats’ the hotkey anyway, I never need use it. But backspace delete removes an edge and all dependent vertices, or vice versa.
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Thank you poopipe ans sage for valueable insight!
Not exactly my geo. To proxy out stuff quickly, we tend to use free models. Fine with max… not with maya i see.
Do you apply cleanup tool in object mode with selected object, or with selected particular component?
btw: Ctrl + del, deleted edges with vertices. -
Delete doesn’t work like in other programs, like I said. I expect a hole in the mesh when I delete a vert, face or edge. It does not happen in Maya. So what I said is very true. To clarify, when you delete a face in Max, Maya, and Blender you get a hole in the mesh. When you delete an edge or vert in Max and Blender you get a hole in the mesh. When you delete a vert with backspace or the del button nothing happens. Again what I said is very true. When you do the same with an edge the edge is removed but the verts and face remain. Ctrl + backspace gets rid of the edge and verts but the face remains.
Dissolving an edge or vert is what happens when your press ctrl + delete or ctrl backspace. That doesn’t always work. Sometimes Maya makes two edges on top of each other. When it fails it seems totally random as well. What else doesn’t work sometimes, bridge, weld, target weld. It’s awesome to model in this program.
I take great pride in making clean geometry but I spend hours at times fighting the program because it just want to do weirdness. Maybe the student version of Maya comes with Grimlins, but I doubt it. I usually just use mesh cleanup if needed. I get the error when unwrapping at times.
At any rate I am not bashing Maya. I really have no interest. Max and Blender have their own issues. I was just sharing some workarounds I have developed to deal with how Maya at times makes cleaning up geometry a total hassle with Axcel.
Autodesk acquired Alias back in 2005. Modeling in Maya felt like a 20 year old modeling software back in 2017, after using Blender. Now that 2018 has the smart duplicate options I enjoy modeling in it a lot more, except when I get geometry issues. I just feel it shouldn’t be so flaky.
@Axcel I apply cleanup to the object in object mode. In the remove geometry I turn on lamina faces and nonmanifold geometry.
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i dunno, those things you mention never give me issues. It’s probably a matter of expectations. You have experience with many programs and thus expect things to work a certain way. And probably your typical workflow isn’t in perfect compliance with the way Maya works. But I only know maya, so the way I’ve developed of working just doesn’t develop any issues with common tools like bridge, target weld, etc. I used to, so I can imagine what you might be doing to cause these issues, which is why I suspect it’s more often user error case. Not implying you are a dummy or anything, just that you have workflow habits better suited to different programs.Like, to me, delete a vertex causing it to chamfer and make a hole seems counter-intuitive. Like adding extra steps I may not have wanted. Just doesn’t make sense. My normal workflows don’t usually have me deleting vertices at all really.Anyway, not trying to drag out some silly argument, but the thing is when more experienced people say things like «argh, maya sucks!» and some newbie reads that, then the next time they have some difficulty in maya they’re gonna quit and waste time trying to learn some new program when really they don’t know any better. I understand there is more nuance behind your decision making but when it gets distilled down to, «this program sucks» it just kind of perpetuates this bad attitude among lesser experienced folks.
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Thank you poopipe ans sage for valueable insight!
Not exactly my geo. To proxy out stuff quickly, we tend to use free models. Fine with max… not with maya i see.
Do you apply cleanup tool in object mode with selected object, or with selected particular component?
btw: Ctrl + del, deleted edges with vertices.That’s a workflow I can identify with, and one that maya doesn’t take naturally to.
Cleanup only works in object mode.
It’s best to be targeted with your selected options in the cleanup dialog when dealing with shit meshes.As I said, tell it to select rather than cleanup, pick a couple of related things to search for at a time, delete/weld them as appropriate and clear history between each step. Clearing history is important because old shape node information will interfere with results
The most insidious errors are unwelded coincident edges that share the same vertices. I’m not sure cleanup will detect those but you can usually spot them by highlighting border edges
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More useful info. Thanks poopipe!
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Introduction -
What is a non-manifold geometry? -
Why you must have manifold meshes for 3D Printing -
How to fix non-manifold geometries -
Make sure your 3D model will be 3D printed
Introduction
3D modeling software can be great tools as they enable you to turn your ideas into shapes. On the other hand, they can turn into a nightmare when you run into design problems, such as non-manifold edges. It is a common case that you may upload a 3D file for 3D printing, but since it contains non-manifold geometries, it fails to be printed. In this post, along with other guidelines we provide you regarding how to fix your 3D files, we will try to figure out how to fix non-manifold issues and to prevent this kind of errors from happening. Let’s make sure together that you will prepare a printable 3D design!
What is a non-manifold geometry?
A non-manifold geometry is a 3D shape that cannot be unfolded into a 2D surface with all its normals pointing the same direction.
Normal is a vector that is perpendicular to the surface of an object. While 3D modeling, normals are parameters that the designer sets manually, or they are defined automatically by the software.
The image below demonstrates in an illustrative way what a normal is.
A vector field of normals on a surface – Image from Wikipedia
This is a very common error that may occur while creating a digital object. This is because during the creation of a 3D model some operations may create unattached surfaces or they may divide a surface. It may also happen that faces attached to each other are connected to a single point, and not to a single edge. Thus, you get a non-manifold edge. In addition, errors that create a shape without volume should be fixed or eliminated at all. Once you are in the 3D modeling software, these kinds of errors may not be visible, as you are dealing with the shape and the volume of the 3D model as a whole. Though, when 3D rendering, the 3D model is being converted into a 3D frame model. During this procedure, its edges and its vertices are being specified and the object is being drawn as a set of lines at the location of every single edge.
So, if a 3D model contains non-manifold modeling errors, will look different when rendering the 3D file. If its wireframe is not precisely determined, the software of the 3D printer will have difficulty in reading the file, so it may not succeed to print the object.
Why you must have manifold meshes for 3D Printing
Without getting very technical, non-manifold geometry is a geometry that cannot exist in the real world. Meaning that a 3D model can be represented digitally, but there is no geometry in the real world that could physically support it. Since the mesh of the 3D model is defined by edges, faces, and vertices, it has to be manifold. If it is a non-manifold mesh, it means there are errors in the 3D model that cannot define with precision the geometry of the 3D model. The software of the 3D printer is reading the exact geometric representation of a model so as to print it. Thus, in case the 3D design contains non-manifold modeling errors that prevent this precision of geometry, the 3D file will not be recognized by the 3D printer, and consequently, the 3D model will not be printed.
How to fix non-manifold geometries
Type of non-manifold error n°1: Multiply connected geometry
The shape in the image below represents a typical non-manifold geometry, which you can also find as “T-type”. In this case, there are three faces sharing a single edge.
Correcting non-manifold issues like this is easy: you should eliminate the non-manifold surface either by giving it volume or by deleting it completely.
Type of non-manifold error n°2: Several surfaces connected to a single vertex
In the following picture, we see another common non-manifold geometry, which is often called “bow-type”. In this case, there are more than two surfaces connected to a vertex. This is practically impossible, as there cannot be multiple faces sharing a common vertex but no edge.
This error could be eliminated by either disconnecting the cubes from each other or by deleting one of them completely.
Type of non-manifold error n°3: Open objects
This model represents a cube with surfaces with zero volume, as well as there are two missing surfaces. In the real world, this model cannot exist as it is.
In order to fix this geometry, you have two alternatives. Either to adjust the wall thickness of the box or to close the box with adding two new surfaces. In both cases, the cube has a valid volume and it can be 3D printed.
Type of non-manifold error n°4: Internal faces
In the following image, we see the wireframe of a cube. From this perspective, we see an internal face that is totally unnecessary.
This error can be easily fixed by just deleting the internal face. If you do not delete that face, the software of the 3D printer will have difficulty in reading your file.
Type of non-manifold error n°5: Opposite normals
In this example, we see a single shape with two adjacent faces which have opposite normals. This error could be hard to detect, as it is the least obvious one.
Once you detect the error, it is easy to fix it, by just reversing the normals, so that they point the same direction.
Make sure your 3D model will be 3D printed
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Common 3D printing problems: What makes your 3D file non-printable -
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