Flipped faces + How to get normals all facing the same way?

[Kidd_Kosmonaut]

Importing CAD models into Max and they're coming in with random amounts of flipped faces. Is there an automatic way to get all normals facing the same way (outward, not inward)? I thought this would have been accomplished by using a "normal" modifier and then checking "unify" but it appears to do nothing as far as flipped faces are concerned. Thanks

[miledrizk]

Hi,

In the Normal modifier, the Unify feature works on Editable Mesh,

So you can convert the object to an Editable Mesh, or you can add an Edit Mesh modifier

And then apply the Normal modifier and check Unify Normals.

[Kidd_Kosmonaut]

Hey thank you for your reply. I will give that a shot.
Part of this may also be a bit of user error as I realized shortly afterwards that not all the verts were merged so I think that may have been contributing to the issue.
Things to keep in mind for next time I suppose. Thanks again!

[torquemod]

I just wanted to add, if you have a really problematic mesh and unifying the normals doesn't fix the flipped ones, you can turn on a visualizer to show all of the flipped normals in green:

https://www.youtube.com/watch?v=f3apTWsPzdg

Typically you want to reset X-forms, then weld all of the verts and unify normals will work, but rarely it doesn't so this is a great helper.

Also, because this fix still involves a lot of manual selection, I tried importing the mesh into blender and then going into edit mode, pressing A to select all the faces, and then Shift + N to recalculate the normals. The funny thing is they looked fine in Blender when I imported them, but broken when I recalculated, but when I exported them out of Blender and back into Max, welding the verts and then unifying the normals again fixed most of the faces. There were only a few that I had to manually select and flip.