Were I writing your paper, I would look among anthropologists, psychologists, or sociologists. Some philosophers might have written on the subject, but scholars in other fields definitely have.
I am thinking of Keep The River on Your Right by Tobias Schneebaum. It was published in 1969, and is a good lively read. The book deals with Schneebaum's encounter with the isolated Arakmbut tribe in Peru. The book deals much more with cannibalism than nakedness, but the description of his first encounter, in which he was stripped naked and investigated in detail is worth a read. Schneebaum wasn't mortified, apparently, and certainly the Arakmbut were not embarrassed either.***
Not every group of people is troubled by nakedness and shame. Any number of groups have been encountered who did not feel shame about being naked, though their "discoverers" (like missionaries, anthropologists, or conquistadores) may have felt intense shame about their own own nakedness.
Shame and nakedness need not be seen as natural and necessary.
People feel shame about certain actions (theft, nakedness, sexual acts, religious acts, etc.) because they think these actions are wrong. Or they believe their bodies are very inadequate -- too thin, too fat, too pale, too dark, too this, too that -- and they are embarrassed if other people see them naked.
I overcame a good deal of shame about my body by a method similar to "flooding" which is used to overcome phobias: I found a park where other gay men sunbathed in the nude and I did likewise. Undressing in public and laying on a towel in the open took a lot of nerve on my part, but it was
curative. After a few visits to the nude park I began to feel less and less shame about my appearance. (I discovered that I had misapprehended how others saw me.). In a couple of weeks I was cured.
There is also "modesty" -- a condition where people avoid being seen naked because they think it is wrong, They may not feel shame about it, but they do avoid nakedness in the sight of others.
All that sunbathing was about 40 years ago. Its benefits (aside from a couple of basil cell skin cancers) has endured.
***Summary: Keep the River on your Right is a short memoir written by painter/anthropologist Tobias Schneebaum and published in 1969. It is an account of his journey into the jungles of Peru where he is accepted by "primitive" Indians and ultimately a tribe of cannibals named the Arakmbut, which he refers to by the pseudonym Arakama. Schneebaum was presumed dead by colleagues, friends, and family after he disappeared for years into the jungle, the last westerner to see him was a missionary who had given him instructions he would find the cannibals if he "kept the river to his right." However, Schneebaum struck up a friendship with the Arakmbut based partially around his considerable art skills and his interest in theirs. The book is most renowned for its anthropological observation of flesh-eating rituals and the honest, light-hearted style in which it was written.