Is it possible to connect a shape with Flip Faces true and one false?

[AssaSquid]

The question is a bit confusing, but here is a better explanation:
I’m trying to build a level that goes from exterior to interior… So the beginning of the corridor needs to exist from both the inside and the outside, let’s say:

But then we don’t need all the extra fluff, so an interior corridor that you can only see from the inside makes sense:

The issue now is… how can I connect those two?

(I guess now it became more of a mind exercise for me… I think the better solution would be to hide a transition from exterior to interior somewhere… Not sure how they do this kind of stuff in a game like let’s say Zelda Tears of the Kingdom, going in a cave.
In this case we would then have another issue, the directional light wouldn’t cast any shadows in the outside world too.
But still wondering if there is a way of achieving this with CSG shapes.)

[OboShape]

been having a play around, but from what ive seen, csgmeshes all do a boolean operation and therefore create a closed mesh after it.

i cant think of a way right now, ill keep having a play around, but hopefully someone who has a little more knowledge can chip in as well, as it could be handy

[BH67]

Let me preface this by saying that I’ve read your question several times over and I still don’t really understand (sorry about that), but I had a crack at it anyway because I figured it would be a good way to learn more about using csg shapes.

My best guess is that you’re looking for a way to “eliminate” this orange face so these two corridors can be mated together cleanly like lengths of pipe:

Does this do what you’re looking for? I’ll provide more details if it does:

There was a bit of smoke and mirrors involved in making this, but that’s half of game dev in the first place, right? =)

Also yes, @OboShape’s point makes perfect sense, as non-manifold meshes can apparently cause lots of nastiness.

Edit: I just realized I should’ve explained that I separated the two corridors here for clarity; you can indeed butt them together and this solution still works.

[AssaSquid]

@OboShape

ve seen, csgmeshes all do a boolean operation and therefore create a closed mesh after it.

I ended just doing an interior level instead. It made more sense at the moment than just waste a lot of time trying to make CSG shapes do what they are not meant to .

I guess this kind of situations would be handled differently outside of a prototype, like modelling the corridors in Blender and removing the unnecessary face to be able to connect the two corridors.

[AssaSquid]

Thanks for the answer! An yes it seems like it’s doing what I was trying to achieve. You were right, I was trying to remove the face you highlighted!