topic Boolean Union Error... in Meshmixer Forum

Boolean Union Error...

Anonymous — Fri, 28 Sep 2018 00:50:22 GMT

Hey guys !
Been playing with MM for a project of mine, but I'm stuck for a couple of nights on one error I can't manage to solve.
I'm trying to merge two objects by Boolean Union... But I keep having errors no matter how much I try.

I've read somewhere that remeshing your 2 objects by Linearsubdivison helps, so I did it but I keep having this red result in the end.

I'll link the pictures to the post of the two items I'm trying to merge and the results after boolean union. Any idea is welcome !

Thanks a lot

Re: Boolean Union Error...

Anonymous — Fri, 28 Sep 2018 00:52:11 GMT

Nothing, double post

Re: Boolean Union Error...

Anonymous — Fri, 28 Sep 2018 08:45:59 GMT

Booleans search for the intersection line(s) of two meshes A and B . A problem rises if there are identical topology regions on both meshes (e.g. the plane region on your meshes shown in the first image). Here MM can't decide whether to use the surface of A or of B. This conflict results in too many (maybe infinite) intersection lines.

BooleanDifference can handle such identical (coplanar) surfaces if you enable HandleCo-Planarity and set the Delta value right. Compare: MM Booleans and its Handle Co-Planarity section.

Unfortunately this doesn't work for Union or Intersection.

So you'll need to avoid such identical regions on the to be joined meshes using BooleanUnion. Often a minimal offset is enough.

As an alternative you might combine both objects and run MakeSolid on it. If you set its SolidType to SharpEdgePreserve and a high enough SolidAccuracy- and MeshDensity-values this should result in a nicely merged surface.

Re: Boolean Union Error...

Anonymous — Fri, 28 Sep 2018 18:51:11 GMT

Thanks a LOT.

I learned a lot about Boolean thanks to your answer and reading the MM wiki.
Actually, I read it before but couldn't understand a thing for some reason your message made it clearer.

Here is the final result after combine + make solid sharpedgepreservation.
I set the mesh densisty and solidaccuracy at 300.

Thanks again !