Take a look at the following:
http://discourse.techart.online/t/fresh-ta-looking-for-advice-regarding-expanding-my-skills-set/10830
http://discourse.techart.online/t/where-to-begin-in-my-tech-art-journey/11324
I will say that you absolutely don’t need to come from an art background to be a technical artist, but it certainly helps. You also don’t need any formal development experience to be a technical artist, but again it helps.
While I went to an art school, I’ve never formally worked as an artist, I hopped over to tech art after a detour through level design. But I’ve used the same tools that artists use, and gone through the same pipelines that artists go through, and having that shared experience and shared language is incredibly valuable.
Also, keep in mind that tools engineers exist. You don’t have to be a tech artist to improve the lives and workflows of your team, just don’t forget that tools are written for the users, not the data.