How to flatten a face to avoid distortion (make an ngon planar)

Question

I created a kind of procedural modeled ground (rocks desert like), with some decimate modifiers to have a really crazy topology.

The result is nice, except for some ngons faces that contains some weird normals, due to the elevation difference of several vertices:

enter image description here

How to avoid this? My first guess is to "flatten the face, but I can't figure out the way to do this operation.

I must specify that the face is not perpendicular to the Z axis, so a zero-Z-scaling (S Z 0) won't work here.

This question doesn't state if you mean to flatten a single face - or many. — ideasman42, Jun 03 '15 at 23:18
Update, this is now included in Blender 2.75, http://blender.stackexchange.com/a/32276/55 — ideasman42, Jul 18 '15 at 10:39
For a very complete answer, see a duplicate question here https://blender.stackexchange.com/a/46268/52815 — Jethro, Jul 01 '18 at 15:52

score 27 · Accepted Answer · answered Mar 13 '14 at 00:25

27

You can scale along the normal.

Set the Transform orientation to Normal in 3D view > Header:

enter image description here

Then press SZZ0.

answered Mar 13 '14 at 00:25

gandalf3

1

so useful! I have spent hundreds of hours in Blender without knowing that was possible. – Steve Jan 08 '17 at 22:52

ideasman42 · Answer 2 · 2018-07-01T20:51:59.307

21

Since version 2.76 there is a flatten faces tool:

Mesh -> Cleanup -> Make Planar Faces

edited Jul 01 '18 at 20:51

answered Jun 11 '15 at 12:27

ideasman42

Vader · Answer 3 · 2014-03-13T00:36:19.893

14

You can also use the flatten tool. This tool is part of an add-on that comes bundeled with blender. It is called "Loop Tools"

enter image description here

You can invoke it by going to the loops tools in the specials menu, W -> Loop Tools -> Flatten. enter image description here

You can enable it in the user preferences:

enter image description here

edited Mar 13 '14 at 00:36

answered Mar 13 '14 at 00:30

Vader

This one works to flatten any surface even on angles, while the others above this post only seem to work when directly on the ground. Maybe I couldn't figure out the others but this one solved my issue and is great for cleaning a messy mesh while retaining rotations. Thanks for the tip! – Cover Club Media Oct 09 '17 at 21:37

score -1 · Answer 4 · edited Nov 16 '20 at 13:33

-1

A simpler approach to the first answer would be, go to Object Properties -> Scale. And change the x y z value to 0 according to your needs.

edited Nov 16 '20 at 13:33

Lukasz-40sth

answered Nov 16 '20 at 04:49

edusanketdk

4 Answers4