I've always had this question and can't seem to find it directly addressed.
For a 3D first-person game, I'm making simple, old-fashioned crosshairs made of 4 small lines, like in Counter Strike and whatnot.
I was going to make every line draw at the center of the screen, offset away by an amount determined by the weapon accuracy. Your usual crosshair stuff.
I just never knew how to turn the accuracy into an offset value: should I use a percentage of the screen size, or a flat number of pixels? Or something based upon in-game units?
What I'm concerned about is, will players with higher resolution or a higher field of view have more or less bullet spread compared to other players if I base the measurements on pixels or percentages of the screen?
For example, if two players fire with the same accuracy, straight at a wall the same distance from them, but one player has a massive screen resolution and 90 field of view, while the other has a small resolution and 60 field of view, will there be a significant difference in where their bullets land on that wall?