Some faces are invisible

[Keep it PMA]

[Pte Jack]

screen shot? It may just be a camera clipping problem if you're viewing the model in Blender.

[Pte Jack]

That looks like reversed normals and you're looking at the back faces on top. Check your normals again and actually turn them on. I bet you'll find that they are pointing into the model instead of out. (This is a common problem when you models with scaling things from one side of an axis to the other using S(cale) X(axis) -1)

[Pte Jack]

What happens if you uncheck Write Normal. It may be a quixel/PS thing.

[Mr Chappy]

Is your scale set to a minus value?

If so you may have a double negative effect, this will cause the exact issue you have(in Quixel) in Substance Painter. If so you need to make the scale + (by applying the scale), then possibly redo your normals again after. Then export again and it should work fine.

[Pte Jack]

Oh, that's interesting I have never encountered a double negative situation. Anytime I've use a SX-1 to flip across an axis, I've always been able to set and fix the normals with a single recalc.

[Mr Chappy]

Originally posted by Pte Jack:

Oh, that's interesting I have never encountered a double negative situation. Anytime I've use a SX-1 to flip across an axis, I've always been able to set and fix the normals with a single recalc.

I only know about it from someone else having this problem a few months back. Got him to post his .blend file as I could not see what he had done wrong, still took me a while to figure it out when I had the file... I'd never seen it before either!
It only happens when the scale has not been applied, so it's a - value...

Originally posted by Dkace:

Oh man that helps a lot. I believe you were right, the scale somehow ended up being negative. I have now corrected it and will re-try the texturing.

Cool hope it works for you now :)