i want use de decimator modifier but i cant…
a message apareace…

this is no a manifold!!

what is and how fixed or change???


sorry my english

I’m sorry I can’t help you, I’ve never seen that…


erhhrer…err… you are welcome. :smiley:

Manifold is like a closed mesh = no holes. For example if you cut a Sphere in half and chose to Select ‘Non-manifold’ = it would select only the diameter. That help?

In general: A non manifold mesh has edges that belong to more than two faces.

Often you either have a Y shape in your mesh, or inner faces. Inner faces are often the result of extrusions or joins.

How to fix? Find the wrong edges. This is not so difficult. Use a subsurf modifier, make sure you klick “set smoth”, and recalculate normals. Change to shaded view. The black stripes on your mesh indicate where the problems are.

A non-manifold mesh is one where an edge has more or less than 2 faces attached to it. The decimator can handle the one face per edge case but can’t handle the 3 or more situation. You will have to delete interior faces for the decimator to work.


Finding non-manifolds is even easier: In EditMode unselect everything and click menu ‘Select’ and then option ‘Non-Manifold’.


Neither method worked for me. Select Non-Manifold selects nothing. Adding a subsurf modifer shows nothing out of the ordinary. Yet the decimator still claims I have a non-manifold mesh.

can you upload your blend somewhere?