Yes. Even tho in my family we're very careful to knock, my brothers weren't shy. They worked out a ton and took good care of themselves so they felt extremely proud of their bodies. They never closed their doors if they were naked. Walking back from the shower they sometimes didn't bother putting clothes on. We got used to it pretty quick and it stopped being a big deal.
Me and my sisters were the opposite. No one ever say saw naked by accident, even each other. Seeing each other nude on purpose, is another story.
I walked in on my brother masturbating watching a porno... I'd already saw his thing before I realized what was going on...he's 18. I walked in on my other brother masturbating in bed right away in the morning when I went in to wake him up for school..he's 14. both times I just walked out, completely uncomfortable and none of us have spoken about it. I'm glad! ugh!