Does anyone know roughly based on experience how long it takes to convert mesh to nurbs in rhino of 20 000 faces? (with a relatively good desktop)

Hi @diana.daoud

I’m on a slightly old 2.9 Xeon, and for just 20.000 faces it takes like a second - actually, a little under a second. It’s really quick!

HTH, Jakob

Edit: I know a Xeon is not exactly a standard desktop, but I reckon that a “modern” desktop would be a almost as quick (or even quicker!).

Umm the question would be why are you trying to do that? Even if you can, doing anything with it subsequently will be a pain. All it does is turn each polygon of the mesh into a trimmed plane.

Because I have a height field created model which I want to be able to edit its points etc. Do you have any other recommendation on how to edit this?

Hmm stange its been an hour so far and its still converting. I am using the pcs in my architecture school which all are pretty good.

Hi Diana,
Are you aware that mesh to nurbs makes one nurbs surface for every mesh face?
If you want a single nurbs surface to edit points on then you might be better off by using the drape command.
And if you upload the mesh file (only the mesh) here, or an image of it, then it is easier to give you good advice :slight_smile:

But drape does not exactly turn out like the actual mesh model.
Ive attached the file here below.

No, drape will make a simplified version.
If you need it to follow the mesh better then extracting the points from the mesh (ExtractPt) and using Patch with 40x40 spans might get you a better result.

I seems to need access on Google drive, so it might be faster to just drag and drop it here on this news group.

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Ive granted you access now to the file, it was too large to drop it here

Yeah, so the mesh was 30 MB and it has 1.000.000 faces, not 20.000 :smiley:


I have tired a few things, but it isn’t an obvious solution, so I need to look more at it after work.

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If you describe what you need to do then maybe we can help you achieve your goal with the mesh without having to convert it though :slight_smile:

So what I am trying to do is to CNC this shape into my own casted jesmonie material.
I want to cnc the same surface on the top and bottom of the material so that the flat parts meet and becomes hollow.
So like in the img below I marked a few of the flat parts in red and want these to be cut trough so its a hole.

So the only way I thought of putting these two mirrored surfaces together and eliminate the flat bits would be by making it into a nurb or something editable to cut out the flat bits and put the mirrored bits together.

Also I find the whole surface a bit too similar in level and I want it to have highs and lows like a landscape, I thought I would do that later with z brush but I am wondering if I could do it simply by editing the points and drag them around.

Hi Diana - see the attached file - a simplified version of what I think you want to do…

MirrorMesh.3dm (420.5 KB)


Hi Pascal,

I tried to open it but I can only see this

Hi Diana - please read the text dots outlining the various steps. Does that make any sense with what you’re doing?