1
$\begingroup$

I used edge loops, and then while cleaning up, I had to delete some vertices (dissolved) and then joined them again using faces. Now when i use subsurf modifier, when mesh looks weird. Fairly new and going through a tutorial to create a face model. If someone can point me in the right direction, will appreciate it.

  1. Subsurf Off

enter image description here

  1. Subsurf On

    enter image description here

$\endgroup$
  • 2
    $\begingroup$ You have at least one NGon on your mesh (face with more than 4 vertex) $\endgroup$ – Duarte Farrajota Ramos Oct 4 '18 at 17:56
2
$\begingroup$

The problem is due to faces with more than 4 vertices as the subsurf can only work with triangles (3 vertices) and quads (4 vertices).

Faces with more than 4 vertices are known as 'ngons' (basically 'polygon' with with the 'poly' replaced with 'n' to represent any number (greater than 4) - I can see two towards the top-centre of your image and it is those that are causing the issue.

The solution is to adjust the geometry to replace those faces with tri and quad faces. The easiest way to achieve this would be to simply cut one of the corners off to a tri, leaving a quad.

$\endgroup$
  • $\begingroup$ Thanks, that helped solve my problem. Quick question though, to select all such non-manifolds, I pressed Ctrl-Shft-Alt-M. That gave me all the problematic edges/vertices, but also said that the open holes in the mesh as well as the central edge line on which the mesh is mirrored is also non-manifold, though it has no deformity at all and looks good after applying the subsurf. Is that normal? $\endgroup$ – Ratan Oct 5 '18 at 15:49
  • 1
    $\begingroup$ @Ratan I think you’re confusing the meaning of non-manifold. The faces with more than 4 vertices are ngons, while ‘manifold’ refers to whether that mesh defines a single enclosed volume - two different things. The non-manifolds shortcut will select the unbound edges. To select the Ngons you can use a different function - Select Faces By Sides - which allows you to select all faces with more than a specified number of edges. $\endgroup$ – Rich Sedman Oct 5 '18 at 16:00
  • 1
    $\begingroup$ Oh ok, got it. I think I got confused as ngons and some of those non-manifolds were having the same messed up affect on my mesh after the subsurf. That explains it, thanks! $\endgroup$ – Ratan Oct 5 '18 at 16:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.