topic How to align to planes? in Meshmixer Forum

How to align to planes?

nkloski — Sat, 01 Apr 2023 15:38:18 GMT

I have a problem that has vexed me for quite some time. I think I am missing something very simple.....I use Meshmixer extensively and maybe I have a block on how to do this simple thing (image below is a 3D scan of a tray though you could use a cube):

I have a 3D scan. It imports into MM not perfectly aligned to a coordinate system. How can I tell MM to align one face to the X plane, then one plane to the Y (MM calls this the "up" direction), then center the whole thing?

What I want to end up with is an object that has a selected face parallel/on one axis, and is facing "up", centered at the origin. This is for reverse engineering purposes, etc.....or even to show clients the scan without having to manually "guess" the degree-by-degree alignment.

Ideally, there would be a feature that performs: "Align the object so that it has the smallest bounding box when looked at from 2 planes" but I am happy with a manual process 🙂

Re: How to align to planes?

hfcandrew — Sun, 02 Apr 2023 00:28:21 GMT

Align a surface to the Y axis, accept. Then run align again to your second surface to the Y axis.

Watch: https://autode.sk/3KqcNcm

If you are using scan data your surface will not be 100 flat, so maybe use surface scribble instead. The accuracy of the alignment will only be as accurate as the source surface is flat.

Re: How to align to planes?

nkloski — Sun, 02 Apr 2023 03:17:18 GMT

Thank you! I thought it was something like that, but I was always using surface scribble, thinking that the errors created by the scanner would be sorted out by the scribble command. But I see that the surface point command does exactly what I wanted, and the scribble is always off.....maybe instead of averaging out errors, the surface scribble accumulates deviation or something. Perhaps I will introduce an artificially flat area to my 3D scans to help assist in aligning. I have given feedback to Artec to have an alignment function that makes the smallest bounding box per plane (which would then partner with their already existing "create primitive" type function for initial alignment).

Thanks!