Manifold mesh edges


(www.cadwax.com) #1

In Rhino, Is there a way to remove non manifold mesh edges - other than using a program similar to netFabb

Of course I could model this differently - just wondered if there was anything there for meshes.

non manifold.3dm (506.9 KB)

thx


(Menno Deij - van Rijswijk) #2

SelMesh
ShowEdges

Found 334 edges total; no naked edges, no non-manifold edges.

MeshBooleanUnion
SelMesh
ShowEdges

Found 657 edges total; no naked edges, no non-manifold edges.

Where are the non-manifold edges?


(www.cadwax.com) #3

Sorry, join the meshes before showedges : Found 2281 edges total; no naked edges, 119 non-manifold edges


#4

ExtractNonManifoldMeshEdges should help.

Just curious. why use booleans in this case ? The meshes look like they have been generated from a Nurbs object. Wouldn`t it be better to fix this simple intersection and then create a valid closed mesh from a closed Polysurface ?

c.


(Menno Deij - van Rijswijk) #5

I agree - but no NURBS in the document.

Rhino has, let’s say, “limited” mesh editing tools. It is generally recommended to edit geometry on the NURBS level and to make a mesh at the end of a workflow.


(Menno Deij - van Rijswijk) #6

In this case, the non-manifold edges are due to the fact that the parts are capped. If you remove the mesh faces on the cap using the DeleteMeshFaces command, followed by Join there are no non-manifold edges left.

But, to reiterate, editing the surface is preferred above editing a mesh that has been made from a surface. But, sometimes, all you have is a mesh…

non manifold.3dm (392.8 KB)


#7

True. In this case, the mesh edges where so easy to extract and convert to smooth curves that i´ve taken the 5 minutes to build it with surfaces in order to create a closed nurbs object. There where some other areas causing naked mesh edges which would have been not as easy to repair in a mesh only version of the ring.

surfaces.3dm (2.0 MB)

c.


(www.cadwax.com) #8

Thanks clement and menno for chewing this over.

I have been trying to keep the majority of my rhino models history linked: http://cadwax.com/downloads.htm

Then convert to meshes for milling / rp. https://netfabb.azurewebsites.net has been able to repair all the files so far - and very fast.

Ultimately, I was hoping to automate this in rhino whilst keeping a history linked model.

Kind regards,