How well does Blender handle convex booleans? (possibly technical)

Hello!

See picture at http://pasteall.org/pic/90ad9587eda8074746483a9802d9633f, I need an external opinion on this.

The intent is to cut the highlighted shape from the bigger mesh using boolean. There are 3 other bool meshes of varying complexity which work fine, so I am unsure why this particular mesh doesn’t get removed.

An error becomes evident when setting the boolean to intersect, as seen on http://pasteall.org/pic/d389ee52bbc7bb46ebddc9489743ce6f.

First I thought it had to do with modifiers, but turning the model into a solid mesh didn’t help.

Thanks.

check out this tut

there are also 2 other bool tool in addon

might work

Booltool addon
and there is also Fastcarve addon with boolean tools

happy bl

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Often nudging one of the parts by a very small amount can work, assuming there are no geometry issues like self intersection and/or non manifold surfaces.

Booleans are very sensitive to the quality of the mesh as well as proximity of vertices so if you have tried nudging without success, it is likely a geometry issue.

Hey.

I tried out a few things. I thought it may be proximity but it doesn’t look like it.
The panel in question is simply not cutting the base mesh.

Please, see for yourselves:
http://pasteall.org/blend/index.php?id=52023

Btw Ricky, I think there’s a typo in your article - “CTRL-L to invert selection”

I don’t have 2.8 loaded on my system at the moment. I will install it and give it a look tonight.

Boolean works well if you have closed meshes
but not always
so might try the other addons and see how it goes

happy bl

I am not using and addons.

EDIT: The solid mesh didn’t cut because the boolean display was turned off. The shrinkwrap still doesn’t cut properly, but at least I decided to just make a hard mesh and boolean with that.

But I’d like someone else to try the following recipe, because I just tried it in 2.79 and results are less than spectacular:

  1. The objects are not very important
  2. The “Host” modifier stack is: subserf, boolean
  3. the “target” modifier stack is: subsurf, shrinkwrap, solidify, (smooth or no smooth)

It looks like the shrinkwrap modifier causes the error. A plane, “solidified” into the host object still booleans normally, but adding the shrinkwrap to it makes it have no effect on the base mesh, or at least it becomes unstable.
Playing around with settings in 2.79’s simple scene still cut the target mesh out of the host, whereas in the 2.8 scene it just doesn’t try to cut even if I apply all modifiers and make it a solid mesh.

“screenpanel_model2_BOOL.001” has bad geometry in the area I circled.

You want to produce parts that will be 3D printed?

I uploaded a file with the repaired version of your object in the scene:
“screenpanel_model2_BOOL.001 modified”

Camgen_ext_bug modified.blend (2.5 MB)

Thanks chris.
No, I haven’t thought about printing this, just working on my modeling skill.

I can see what you were getting at, It wasn’t the only problematic area. That piece was originally made from a solidified plane with creased edges; for whatever reason it didn’t want to crease the way I wanted it to and I’m not sure what else I should have creased to get the effect. I’ll try again. Anyway, do you think that caused the issue or is it just a separate note?

EDIT:
Anyone know why artefacts keep appearing in creased edges?
http://pasteall.org/pic/a1441e0fb99f3f274c1fb1f078af6d38

This is the original issue: there remains an artefact regardless of how I crease it. If I only crease the edge it doesn’t get limited, if I crease the corners it twists, and if I crease the second line below this happens. It looks like vertex normals are twisted, but shift-n didn’t change anything. I knife-cut a few lines from the bottom rows up and the new normals were… normal (tee hee), but when I tried deleting or ripping the problematic vertices apart the problem just moved elsewhere. I’ve seen this before, but no idea on how to fix it.
ED2: extending corner creases by 1 line fixed the issue visually, but I’m doubtful. Cutting trigons in places also looked like it worked until you looked closer.

File: http://pasteall.org/blend/index.php?id=52025

I don’t know that it caused the problem. You could use the the fixed part I inserted in to the file and do the same operation with it. I fixed the area in a different application that can trim triangles where they intersect to create a valid solid.