Snapping a group of vertices to one axis

Something I have been coming up against a lot. I delete half my model to work on it symmetrically, then create a mirror modifier to bring it back. But somehow while I’m working on it, it gets moved just enough that all the vertices that were along the center line get moved a tiny bit away from 0 on the Y axis so when I mirror it I get an annoying seam.

  1. How can I avoid this?
  2. How can I fix it once it has happened?

I’m not sure it can be avoided, per se. It happens to me all the time. BUT…

To get them all back in line, just scale all vertices along the mirror seam to 0 and realign to the object’s centre like this:

  • select all the vertices at the mirror seam,
  • ‘s’ to scale,
  • ‘y’ or ‘z’ or ‘x’ to restrict scaling to the proper axis,
  • ‘0’,
  • Enter, THEN (with those same vertices still selected):
  • look in the ‘n’ panel > Transform and zero out the y or z or x position of those vertices.

You’re golden.

So easy! Thanks!

tips, use a mirror modefier…

Ensure you also enable Clipping and Merge in the mirror modifier settings so the vertices are fixed on the mirrored plane

i think that is default :confused: maybe clipping is not default… but anyway good point.