after Boolean objects disappear

[frennyluv]

When I subtract after a few hours, there are no more items in my screen. When I test to try and save an STL it says something like it cannot save an empty or no object file.

My model and the logo I want to subtract are difficult items. It took some programs a day to repair it. Now that all the tags are green Netfabb still can not work with it. Maybe too complicated


It happens more often though, I wait for hours try to Boolean and all items are gone just the pull and push arrows are left and the names are also there but no objects attached anymore.

Netfabb was my last hope to be able to subtract this logo from the item I am trying to 3D print in resin...

[steffen_anders_adsk · Accepted solution]

Hello, @frennyluv,

I have several suspicions about your mesh parts. They may not be entirely fault-free or otherwise suitable for mesh operations. Especially when the faults are very small, very narrow, or very close, or when the faults have multiple possible solutions, proceeding with mesh operations can be tricky. Also, bear in mind that Netfabb's fault check does intentionally not test for self-intersections or degenerate triangles as automatically as it tests for, say holes. This is intentional as those checks are computationally expensive. So, while your parts may not be indicated as faulty, they may still be unsuitable for mesh ops. (For instance, those diagonal streaks on otherwise flat surfaces are good indicators for potential problems.)

I can only suggest seeing to bring the individual parts into a more "friendly" state. Resolve degenerate triangles and self-intersections, remesh parts to get more regular triangles, make sure to have good overlap of individual meshes and shells when you bool them together (coplanar surfaces are poison for booling and wrapping) … in general, bring the meshes into a state where it's clear which side of a triangle is supposed to be inside or outside to get a clean unification or, in your case, subtraction.

Best regards,

Steffen

[MOnique.de.wilt]

hi Frenny luv,

you have probably finished this project but maybe here is a workaround for a next project. netfabb might have less problems with simpler models. So maybe you can use a rectangular box as a easier go between. You might be  able to subtract the logo from a rectangular box .  Subtracting a rectangular box from the model should also be easier for netfabb. place the rectangular box with logo in the rectangular hole and you should be good to go. Hopefully 😉

[frennyluv]

Thank you so much for taking the time to reply. I have done similar things in the past but it never hurts to hear about them again since you can sometimes stare  yourself blind on a problem.

[frennyluv]

I had to go all the way to the beginning almost  😞  
It's been done now but at a high costs of time. Thank you again Steffen, always here for me 😄

Because I work with very high detail in resin printing, I work with a (maybe ridiculous amount of) smoothing) Do you happen to know how I can reduce err... the polygons (?)  to make the object more workable because the computations sometimes are stuck or just take hours or a day 🙂
>without losing any detail on the outside.

Kind regards.

[steffen_anders_adsk]

@frennyluv,

That really depends on what your source of parts is. It would be silly of me to tell you to not have complex parts in the first place when you don't have control over your source files and all you get sent are mesh, not CAD data.

Yes, there are ways to reduce triangles, but they of course can bring losses in quality when they form curved surfaces. You can try Reduce triangles, or Remesh, the latter of which has two main methods, Uniform and Adaptive, and both of them can be made to act only on selections and to not destroy angles between adjacent triangles beyond a certain threshold, like sharp edges and corners.

You may also be able to completely rebuild an offending surface by deleting it, inserting pilot triangles, and closing the holes so generated, but that becomes unfeasible quickly for anything beyond flat surfaces.

Beyond trying to process or repair a mesh, maybe consider reconstructing the part entirely from scratch using CAD modeling (*cough*Fusion360*cough*) and working off a clean STP export, imported using either CAD handling of Netfabb.

Best regards,

Steffen

[hfcandrew]

Do you have the .stl? I feel like this is something Meshmixer could do in like 30s.

[frennyluv]

I use meshmixer extremely rare because I hate that auto smoothing, things look so weird rounded and the menu's are counter intuitive to me. I've found a solution on the Web but for the file I'm working on at the moment 2.5GB it can't even import because it hangs at making the meshes.

[frennyluv]

I've been wrestling with Fusion but with the little time I have left I was barely getting Netfabb and this additional 3D printer that I am constantly trying to repair with the models being airbrushed and masked etc.

It's hard for me to always completely design from the ground up when it's enticing to just grab an object that has already been crafted nicely and use that to make the prop I need when you are already short of time.


For that reason I'm still doing some things really quickly in *cough* 3D builder. I hope that one day Netfabb takes over most of the tasks and that I can go to 3D Fusion next.
Thank you as always.

[steffen_anders_adsk · Accepted solution]

As an update, it turned out there really was a bug in Boolean that, in very difficult-but-not-impossible constellations, would indeed reduce a part to nothing. With the release of 2022, that bug should be fixed.