I think the most important kind of math is linear algebra if you are serious about building something from absolutely zero. Achieving mastery over the rendering

I think the most important kind of math is linear algebra if you are serious about building something from absolutely zero. Achieving mastery over the rendering pipeline requires lots of experience with matrices. Some of the more esoteric stuff might take you multiple papers/books to fully-grok. An example of this for me was clipping of geometry against the view frustum (for building a software rasterizer - GPUs handle this for you now). I've got 3 different papers on this exact topic still sitting on my coffee table. I think the hardest overall aspect is thinking in 4 spatial dimensions and getting your head around all of the transforms. If you are using a 3rd party engine like Unity or Godot, you may find that mastery of this stuff is not as essential. I think it still helps to understand how the scene graph is ultimately rendered, but unless you are building these engines with your own hands, worrying about acquiring this knowledge could be prohibitive to progress.