I had this doubt in my head for several months and have been unable to find an answer anywhere on internet.
I know what OpenGL, DirectX, Vulkan, Metal, etc... are, I already know what they are used for (literally in any multimedia software application).
My question is "in the real world when people work directly with a graphical API (eg: DirectX)?".
For example, if I want to create a game I will use a game engine, if I want to create special effects I will use a program for VFX, if I want to create an animated scene with different 3D models I will use something like Blender.
What are the situations where a person could say "Ok, this problem can only be solved by writing my own software with DirectX/C++"?
My question arises from the fact that I would like to learn DirectX (later Vulkan also) as a matter of curiosity but I know that graphic programming is a demanding topic that requires a lot (a lot!) of time.
I work for a company most of my day and since the salary is quite low (especially because at 21yo nobody takes you seriously), in the evening I dedicate myself to secondary activities in order to earn something more. I can't find a good reason to stop dedicating myself to these activities to study something that will not lead me to any type of business.
In my country (Italy) there are some (not a lot) job offerings concerning graphic programming but all require a degree in Metematics/Physics, which I don't have.
So, in summary, what are the situations where you need to "get your hands dirty" with a graphical API (eg: DirectX) instead of using a tool already made?
I know there are big game companies that for example reinvent the wheel (they write the rendering engine from 0) because they will pay off the costs and it is not convenient for them to pay for an engine already made. This environment doesn't interest me much because it certainly cannot lead to an individual business.
Other situations where you work directly with a graphical API is the world of simulations, but there I imagine it is more a matter of mathematics and physics, not of graphics.
I'd like to read about some experience of those who work/worked with a graphic API and what your role was in the industry. I'd also like to read about someone who has his own business that somehow relates to a graphical API.
Thanks a lot to everyone :)