SubD is not smooth and is faceted

i understand that however I literally followed exactly your settings (OBJ because stl only exports triangles which would lead to facetation) and this is what the obj looks like in meshlab-- mind you the polysurf nurbs representation is smooth and no facets.

As @maje90 wrote, only the SubD meshing parameters at the bottom of the dialog matter. Use preview to see what the mesh will look like before you export. If the export doesn’t match your preview, then maybe it’s a Rhino issue. With the Subd meshing parameters slider, this image shows the best mesh that Rhino seems to produce directly from your Subd (and I’m on windows, so perhaps Macs have an issue that windows doesn’t)

If you need more mesh control, run ToNurbs before export, hide the SubD, and then all of the mesh controls are available.

It is visible in the triangulation of your mesh that you first converted your subd to a polysurface, somewhere, then you converted your polysurface to a mesh.

2024-04-16 14_39_21-SubD is not smooth and is faceted - Rhino _ SubD - McNeel Forum
won’t happen if you go subd>mesh directly.

Hi @Lucien_Mount ,

I think the confusion here is that in the printer slicing software (Bamboo), the mesh is displayed as flat shaded since that shows the actual geometry you’ll be printing. Even if you have quads in the mesh, if they are not planar they will be broken into two triangles each. I always use .stl format myself when saving files for slicing/printing. The key thing to manage is the maximum edge length allowed in the mesh that you save. If this is smaller than the tolerance of your printer, you won’t see facets in the actual part.

Below is an example using the max subdivisions for SubDs in the Mesh command. Your model is also in Feet units so note that the distance between two vertices is roughly 1 ft. / 12 in. so you’ll likely be scaling this model down to print it as well further reducing the polygon size and the possibility of seeing facets in the printed part.

I hope that helps.

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