Quote: "How are you doing the animation? Is it multiple huds?"
That's what it looks like.
The hole gets smaller in each of 2 or 3 frames (HUDS)
There is a side effect when changing the ambience, color, and displaying a hud at the same time, but I think he did use a few huds.
Only he knows, but it could be the side effect itself.
I had a funny transition thing going on when I first used this method too.
I tried to tweak it with a timer, but I never got it to work perfectly.
Nice job on the HUD Rolfy
Quote: "This method could also be applied to diver's mask with animated bubbles, deep sea helmet etc"
Yeah I been thinking about the bubbles for a divers mask too.