Hello,
I've made a big cave with a Dragon inside.
Sometime the dragon fly inside the walls... How can I prevent that glitch?

Thank you.

If he's a named/unique dragon remove the flight behaviours from his AI Package.

You need to place collision markers in the walls so he knows they are there. Dragons calculate flight paths based on markers, instead of actual object collision, as it's far more optimized than accounting for 80000 small collisions, and he can go through things like rocks and tree's that aren't noticable.

Placed, but still trepassing. What kind of collision and setting I've to do?

I'm not sure. Load the cell Riverwood in Tamriel, and look at the ones there. There are large white collisions in all the buildings, I presume to keep the dragons out.

Well... I'll try tonight. Thank you.

did it work?

Hello,
I'm at office. It's 5pm here (UTC+1) so I haven't tried yet.

I have tried collisions on a still flying dragon one more than one thing
1. Inside a large Dwemer hall I had tiny dragons, ALL walls covered with collision planes--. stilll flying through
2. THe exterior of my flying fortress: I have a few dragon attacks (very nice on a small floating island btw) and I've put collision boxes in all large statics --> still flying through

I'd not do flying dragons inside

I did have a look at riverwood as suggested.. inside the buildings are plane markers

ok so ?

Hello,
I'm back. Riverwood houses have only dragon perks... I've examined the mountain at the side of Riverwood. Doesn't have any box collision...