Struggling to Create Mesh from Surface of Existing Mesh

[mbmast]

I am trying to create a mesh from the surface of another mesh (the attached .3dm file). This file contains a lot of errors. There are 2,331 total edges, 657 naked edges and no non-manifold edges. When the Perspective view is set to Shaded, Rhino renders the model beautifully. What I find frustrating is that if Rhino can render the surface beautifully, why can it give give me a mesh based on that beautiful surface?

I have been attempting to do this for two solid days. I’ve tried dipping into Meshlab, but this too has lead me to a dead end. I strongly suspect that Rhino can do this, only I don’t yet know what I should be doing to get the result i’m looking for.

My objective is to 3D print this object, but I don’t want to print it as a solid object. It’s the base of a telephone and needs to be printed with walls that are 1mm (more/less) thick. Hence my desire to pull a mesh off the surface of the model.

There is a similar posting on this site that suggests using ExtractPt and Patch, but this results in an object that is so distorted it is truly not recognizable.

Fixing all the naked edges en masse produces bad results. The alternative is to fix them a pair at a time, but there are 657 of them. Also, that’s not an even number, so there must be some single naked edge somewhere.

Again, Rhino renders the object beautifully. All I want is a mesh of the beautiful surface.

Western Electric 302 Telephone.3dm (1.3 MB)

[wim (Wim Dekeyser)]

@mbmast

When the Perspective view is set to Shaded, Rhino renders the model beautifully.

When shading, there are a lot of tricks involved. There is smoothing information in the mesh that makes things look good. And that is the way it’s supposed to be - there is nothing wrong with the mesh.

@mbmast

My objective is to 3D print this object, but I don’t want to print it as a solid object. It’s the base of a telephone and needs to be printed with walls that are 1mm (more/less) thick. Hence my desire to pull a mesh off the surface of the model.

The base of your telephone is less than 5 mm wide - having 1 mm thick walls will create self-intersecting meshes. Are you sure your dimensions are correct?

At any rate, in this thread, @laurent_delrieu describes a way of dealing with offsetting meshes:

3d scanned mesh

Hello I have done it using Grasshopper and a script I wrote, you will need Millepede plugin for GH (don’t care of the message) If you want to use the script beware it is a bit long, so Disable solver, put the offset you want 0.9 mm in “real unit”, load your mesh and enable the solver. I made an hole in order to have a unique mesh visible with clipping plane. Instead you must take care of direction (I think). [image] [image] [image] Anello 500_interior.3dm (1.2 MB) I

[mbmast]

Thanks for the reply. What I meant to say was that, when printing, I would scale the phone up so that it’s length (from front to back) would be 193mm (the length of an actual Western Electric 302 telephone) and that the walls would be 1mm thick (or thicker if needed for printability/structural integrity).

I will look into the thread/solution you suggested.

[wim (Wim Dekeyser)]

With this dimension, it appears it’s only at the part in the back where the offset will self-intersect and that can more or less easily be solved by hand. I’m not sure what you intend to do with the receiver and I would say that 1 mm offset is not enough.
Western Electric 302 Telephone-wd.3dm (2.9 MB)