Jim Stormdancer

@mogwai-poet

he/him
twinbeard.com/

Sandwich Imagineer at Twinbeard. Made Frog Fractions. May or may not have already made Frog Fractions 2 through 5.

Jim Stormdancer @mogwai-poet5/31/2024, 7:17 PM

Just learned about PID controllers

https://en.wikipedia.org/wiki/Proportional%E2%80%93integral%E2%80%93derivative_controller

This seems like the sort of thing that could be useful in game dev, slotting in somewhere you might put an easing function with a moving target. But I've never heard of them actually used in practice.

Is it just overkill? I typically use a one-pole lowpass filter for this sort of target smoothing, which is a simple idea (simple enough that every game developer has invented it independently without realizing that it's called a one-pole lowpass filter) and works just fine 99% of the time. Or is it that robotics and game dev have so little overlap that the idea just never crossed over?

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in reply to @mogwai-poet's post:

Nire Bryce @NireBryce5/31/2024, 7:26 PM

it probably has more overhead because more moving parts, which might mean it was ignored and just not looked at again yet, but I'm in dev not game dev

Thew @Thew5/31/2024, 7:34 PM

I think it's pretty commonly used in physics-heavy games? It's a great way to handle like "tears of the kingdom ass" situations, where you're trying to follow player input or npc pathfinding, while uncontrollable/unpredictable external forces are also affecting everything

I wouldn't say it's unknown in gamedev spaces. I've def seen Cool Gifs of people using it over the years when twitter existed, and I still hear devs mention it occasionally. I'd guess it's probably too situational to be, like, totally widespread common knowledge?

Pim de Groot @mifune5/31/2024, 7:41 PM

The problem is probably that you also have to model the inertia of the object you are applying a PID controller to. In engineering you get that basically for free, because you are trying to control a (model of) a real thing.

In gamedev you'll have to add mass, friction, characteristics of the actuator driving the thing, and other physics stuff that can influence the movement of a thing. And that might not be necessary.