Ask Lemmy

I know more about the Doom engine than I do interpersonal relations. Did you know you can completely destroy collision physics via writing over memory addresses if you shoot a bullet weapon at a stack of corpses?

Edit to explain: Decino has a great video explaining it in detail. Link is above, tho I'm at work and can't watch it to double check. Poorly explained from my memory:

When you fire a hitscan attack (press button, gun shoots a bullet that instantly hits with no travel time), the engine does a number of checks for collision, range, etc. If you have a stack of actors (decorations, monsters, ammo, etc) and you fire a hitscan attack in the direction of the stack, it makes a call to check collision for each individual actor in that stack. The actors don't have to be all on top of each other, it just matters that the hitscan line crosses over those actors.

If you have a stack of 129 or more actors and fire a hitscan weapon, the game will essentially overwrite parts of the memory address. I don't understand a lick of that stuff myself, admittedly, I'm no programmer. If you have something around ~140ish actors in the line of fire of a hitscan attack, the Blockmap system for checking collision effectively gets erased. Projectiles pass through everything, bullets and melee do no damage, players and monsters walk through walls, and you can't interact with things like switches. You can fix it by saving and loading, though if you're recording demos you can't save.