Smooth modifier cause gap/hole in landscape mesh I have a problem when using the smooth modifier on my terrain mesh. When used it cause a gap/hole in the terrain. See the images below before and after using the modifier.




I should also mention that I have previously split the mesh and then joined the mesh back together right where this gap occurs.

As far as I can see, all normals are pointing upwards and duplicate vertices have been removed.

I hope this is easy to fix!

Thanks!
Solution:


Select mesh
Go into Edit Mode
Ctrl + TAB and select Vertex mode
Select all vertices by pressing A
Press W and select Remove doubles
In the options panel, set a number greater than 0