It's relatively rare for a player on a non-guaranteed training camp deal to earn a regular season roster spot. This is generally limited to one player every few years. This offseason, five players outplayed their camp invite status and seem to have stuck for the regular season.
This group includes: Isaiah Hartenstein (LA Clippers), Wayne Selden (New York Knicks), Dennis Smith Jr. (Portland Trail Blazers), Matt Thomas (Chicago Bulls), Brad Wanamaker (Indiana Pacers). Armoni Brooks could be included in this grouping as well, but his situation was somewhat unique given his re-signed status and conversion process as a former Two-Way player.
When a player makes an opening night roster on a training camp deal, their contract converts to a standard non-guaranteed contract. Prior to that happening, a camp deal doesn't count against the salary cap or tax, and there is no guaranteed salary.
Prior to this season, Dwight Howard was the last player to go from camp invite to roster. Howard made the Los Angles Lakers roster out of camp in 2019.