For most additive geometry constructed maps, cracks can form to create collision holes which otherwise look solid, or the map may not be entirely closed and have a gaping hole into the void. This is very difficult to get right.
For maps which carve out empty space from solid space and then add geometry back (subtractive, such as Unreal), there may be cracks caused by numerical imprecision but collision errors here are relatively rare.
The first problem is that it's not immediately obvious. Hitboxes aren't tied to what is visible, so just looking over a map won't tell you anything. Playtesting the map also isn't foolproof, because sometimes the lack of a hitbox where there should be only manifests under very specific conditions which may or may not be in the realm of developer expectations.
The second problem is that it's just very complex, and complex things are hard to build right the first time, find any problems, and fix them. Are these two overlapping polygons a bug or intended? Should this polygon have a hitbox? What about this particular face on the polygon, should it have a hitbox or not? How accurately should we be calculating collisions?
The third problem is that game developers, and especially programmers, are paid bad and work in bad conditions. Any programmer worth their salt wants to jump ship over to the enterprise side of things ASAP, where both the pay and the conditions are much better. So you're left with not necessarily skilled/motivated programmers left to deal with complex programs (games) rife with the potential for bugs.
I read ignorant shit about the game industry all the time on HN, but this is so beautifully ignorant, arrogant and demonstrative of what is wrong with software developers that if wish HN had gold to give.
I suppose John carmack, George Romero and jonathon blow would be sad to learn they’re not worth their salt.
Lest someone argue that I’m picking outliers, you’ll just have to take my word that in my years at Microsoft and then in games I have seen brilliant programmers (and bad ones) in both environments. And many of the best in games tried to stick it out at “enterprise software” (google, msft, SV unicorns) but always left within a year despite bags of money being hurled at them.
Sorry if this sounds harsh but I am so tired of people who’ve never walked a mile in the shoes, telling a walker how they must suck at walking. It’s endemic on HN, for all kinds of things, not just games.
Odd examples to choose.
Jonathan Blow made two games with engines developed from scratch. I don't know how you think that's "not particularly impressive" for a solo person, unless you have never tried to actually ship a game. With or without a custom engine.
I was just trying to pick programmer examples that people would know. Probably didn't make my point very well, which was that there are plenty of programmers "worth their salt" in the gaming industry, and who chose to stay in it. To state otherwise is just fucking idiotic.