Subdivision modifier creating face orientation issues on an object with a hole in it

Hi there, I’m a blender beginner and must say since starting, I have fallen in LOVE with it. I’ve been learning through tutorials but can’t to find any information on this problem I have gotten myself into.

In short I have modelled a cube with 3 x boolean modifiers, an array modifier, followed by a circle modifier. The object is turned in to a mesh and then is followed by a subdivision surface.
When I get to this point I keep getting a face orientation problem on the area where there has been a cylinder boolean cut.

I’ve tried remodelling it and tired different sized cylinders as well as trying to remesh it, but my computer seems to crash everytime I try to remesh followed by the subdivision.

If you click on the image link there’s a few different images showing what the object looks like before the sub division is applied, and the final image shows the face orientation issues.

Would anyone be able to help me :slight_smile: Would really appreciate any advice anyone could give me!!! :slight_smile: Thank you in advvvannnceee :slight_smile:

Hello and welcome to BA,

The subdivision surface modifier relies heavily on good topology, the boolean modifier doesn’t create clean topology so you either have to fix it manually or rely on a different worklow like using a higher poly mesh with bevels for softer edges.

Thank you for the response @GrimZA ! With a higher poly mesh, are you suggesting subdividing my first object, and editing it without the booleans?

No, the higher poly mesh is there to smooth out the shape.

Under object data properties > Normals there is an auto smooth function, when a mesh is low poly the boolean cuts will cause shading artifacts when the mesh is smoothed, a higher poly mesh will sort of hide the issue so you can model with a bit less care.

With a bit of tweaking you can still use the Subdivision surface modier with the Boolean Modifier but you won’t be able to apply them without shading issues.


Thank you for the reply. Just giving it a go but still struggling a bit haha… I think will take me a bit of time to test what you have told me :). I HOPE it works for me haha!