Valalta is, according to my experience, in the top 3 best nudist resorts in Europe and probably at the top of the list. You have every comfort you can demand, the location is wonderful and so Rovinji. In the summer the weather is always sunny (in 4 years, i had 2 rainy days) and warm.
Nudity is very respected, also by teen kids, totally at the pool and on the beach.
The village and the sea are clean, with many extra activities (soccer, kids clubs, tennis, bikes, archery, table tennis), and the working people are polite.
It's very crowded, especially in july and august, especially by families (germans, italians, croatians mostly), but quiet, not loud (pubs close early), so the nights are noiseless.
As a teen, and nudist, it's the best place where I could go.
PM me if you have questions.