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Comment by 6374532 | Hacker News Reader

This was one of my favorite games to play as a kid. I played it for many hours. The physics, engine sounds, in-car view were really impressive. It is still my favorite racing games to this day. It left a greater impression on me than any other racing game I played since. One question I had is, why weren't cars able to flip upside down in the game? This wasn't a large negative, as the the way the cars crashed and showed damage was quite good. I laughed so much as a kid playing this game, it was pure excitement for me.

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The coordinate system for the race management/graphics engine in that game was a 2D system (and in fact was (lat, long) on the track, rather than (X,Y)). We'd convert the (lat, long) into (X, Y, Z) coordinates, take into account the banking and track surface under each tire [painted lines were slightly more slippery than asphalt], do all the physics computations, then cast the (X, Y, Z) back to (lat, long) to send it over to the race/graphics world.

Why? Longitudinal measurements are natural for "who's in the lead?" type of questions and all of our track editing tools also worked in lat/long coordinate space.

Just to clarify, do you mean polar coordinates [1]?

That would absolutely make sense for a game centered (heh) around racing around a closed track, clever!

[1] https://en.wikipedia.org/wiki/Polar_coordinate_system

Not exactly. Polar is r-theta. The system we used was an x-y system, but one where the coordinate system alignment changed for each track segment. So, think of a world where a straight line in y ["longitude"] was projected into a constant path relative to the centerline of the track's racing surface.

(While most NASCAR tracks are ovals and could be represented in polar coordinates fairly naturally, they do have some road courses and the physics and game engine originated in the IndyCar game, which has even more road courses.)

Wow, that's amazing, a lot of time spent on that game :) Thanks for a great game!

Your coordinate system make sense, and the 3D engine/physics was pretty good for something running on CPU only. (If I remember there was only one or two non-oval tracks)

I share somewhat the same memories. I remember putting hours and hours into that game to see what was possible and what were the limits. One of the earliest memories I have of figuring out how software works and what it's limits are.

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