Caution advised. Before carrying on, I strongly suggest to check your professor again to see if they welcome the change.
I am starting my work on my bachelor thesis. Starting means finding a topic and doing research at the moment for me. ... The problem is we don't really have a professor who is specialized in this field. Which mainly is why I have no experience here.
The nearest thing I did was a course about audio & video programming lectured by a prof. who worked at steinberg. Off him I learned my basic C++ skills.
So I was thinking about a good way (project) to learn about graphical programming which I an turn into an bachelors thesis if things go right.
Back when I was attending university we had an official 3D graphics course. Apparently, rendering 50 lights per pass didn't impress them (in 2005 I think).
By contrast, the stupid scripting language used as scene description made them go crazy.
The university I attended had a reputation for being very theorical (over 75% of the courses didn't involve a real world processing device). I had the impression they didn't like my hands-on approach in general.
So, are you 100% sure they would welcome a thesis which appears to be not in their current skill set?
As much as I hate to write this, your goal is not to do what you want. Is to reach your target.