Invalid mesh fix?

Grasshopper
1

Hey guys,

And idea what is going on with this mesh and how to fix it? I am importing .obj files with shapediver import plugin. And all of them are invalid but mesh join unify and clean usually resolves it. But there is a one or two meshes that are not affected by this fix.

Here is an example one: invalid mesh.gh (112.7 KB)

image
image1086×336 31.9 KB

Thank you for your help in advance!

Regards,

Jonas Blazinskas

Edit: As a matter of fact mesh join alone usually fixes it.

2

Hi Jonas,

i usually bake the mesh and run the “Check” command in rhino to get a quick idea of what went wrong.

3 
General information about this mesh:

Mesh has 71 degenerate faces.
Mesh has 73 non manifold edges.
Mesh has 9 duplicate faces.
Skipping face direction check because of positive non manifold edge count.
Mesh has 510 pairs of faces that intersect each other.
  This can cause problems if you're doing mesh boolean operations with it.

Mesh has 123 naked edges.  Naked edges can cause problems if the ultimate goal is STL output.
Mesh has 52 faces where the face normal differs substantially from the vertex normals.
  These normals can cause problems if the ultimate goal is for rendering or boolean purposes.

Mesh does not have any ngons.
Mesh does not have any extremely short edges.
Mesh does not have any disjoint pieces.
Mesh does not have any unused vertices.
ON_Mesh.m_T.Count() = 1491 (should be 0 or 6884=vertex_count).


ID: 3c23f847-bd32-4488-9870-b325b72bcf26 (6215)
Object name: Mesh: ON_Mesh.m_T.Count() = 1491 (should be 0 or 6884=vertex_count).
Layer name: Default
Render Material: 
  source = from layer
  index = -1
Attribute UserData:
  UserData ID: CE28DE29-F4C5-4faa-A50A-C3A6849B6329
  Plug-in: 17b3ecda-17ba-4e45-9e67-a2b8d9be520d
    description: User text (1 entries)
    saved in file: yes
    copy count: 2

Geometry:
  Invalid mesh.
  Open double precision polygon mesh: 6884 vertices, 13710 faces with normals
    Bounding box: (-5.01,-30,-9.249) to (165.01,0.01,9.249)

What am I after here?

4

You might consider taking this one to a vet.

5

Unfixable? What is precisely wrong with it?

6

It seems your mesh has many duplicated faces and degenerated faces…
After some operations, now it’s valid one, but still has many naked edges, so it could be a problem when you 3dprint it…

Canvas at 04;24;21
Canvas at 04;24;211430×237 76.4 KB

invalid mesh_reV1.gh (118.5 KB)

7

Don’t mind it if it doesn’t 3d print as long as its a valid geometry and can be rendered I am cool with it!

Thank you for your help!