Move the function with WASD (h, k) Zoom in and out with Q and E Change the a variable with left and right arrows Change the b variable with up and down arrows Hold space to change a and b slower (useful for floor) press H and K to reset (h, k) individually press Y and I to reset a and b individually press J to reset zoom press numbers to change function
Made with my current knowledge, which isn't a lot. Zooms below -100 won't show properly, and ones too high will have less detail.
