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Comment by jsrcout | Hacker News Reader

I took an intro to computer graphics class in college in the mid-80s. Was so bummed to find out that it mostly about matrix multiplication (according to my hazy, non math-guy memories). I mean yes I wanted to write software to do graphics, but I wanted to do graphics, not just math. OpenGL was still in the future; maybe PHIGS was around, but I'd never heard of it then. The situation is just so much better these days.

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I'd argue that understanding the math, ideally having written it yourself at least once, gives you a massive advantage when using an API later. If you don't understand the math, you might find yourself wondering why certain things don't work as you expect, or copy-pasting code you don't understand from Stack Overflow (or doing enough research to understand the math anyway).

I think a very illustrative case for OpenGL is what's up with all the glPushMatrix(), glPopMatrix(), GL_MODELVIEW and GL_PROJECTION stuff. Do you glTranslatef() or glRotatef() first -- and why does that depend on whether you're moving the camera or an object?

I found all this very confusing, and I'd just try permutations of the calls until things worked, which is a suboptimal way to write software. At some point I decided to really understand what was going on, to the extent that I ended up teaching it (best way to verify if you really understand something!) and even writing about it [0] (even better way?)

TLDR: Even as the user as an opaque API, understanding what's happening under the hood makes you a better user of said opaque API.

[0] https://gabrielgambetta.com/computer-graphics-from-scratch/1...

Or why the operations are order dependant >D

> I wanted to do graphics, not just math.

Much of CG is basically an exercise in linear algebra.

Almost anything technical or even moderately mathematical is an exercise in linear algebra (effectively by design).

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