I can’t remember the math. But when I was in high school I remember stumbling on this paper or something similar while working on a 3d engine. I programmed my g

I can’t remember the math. But when I was in high school I remember stumbling on this paper or something similar while working on a 3d engine. I programmed my graphing calculator to use it and basically “cheated” my way through a large bit of calculus with some variations on the code for each type of problem. This was 20-something years ago, so I don’t remember the details except that it didn’t work for every real problem, but most textbook ones and it used matrices.