Little boxes / on the game sprite / little boxes / made of rectangles

April 19, 2017 11:33 AM

Here's a flickr album of images of and about hitboxes, the simplified mathematical regions—sometimes literally boxes (whether 2D or 3D), sometimes other shapes—used to quickly calculate collisions between objects in video games.
posted by cortex (13 comments total)

Nice post - there's some cool and recognisable titles in there. Now having the urge to get yet another Dreamcast and nostalgically replay Soul Calibur...
posted by Wordshore at 11:58 AM on April 19, 2017 [1 favorite]

These are really great. It's a weird feeling, seeing these overlaid on sprites and shapes that are so familiar. It's like, were they in some cases this crude, and in some cases this exact? Interesting stuff.
posted by BlackLeotardFront at 12:55 PM on April 19, 2017

This appeals to me because I too don't think we would be successful if we tried to change concepts just to sell more.
posted by Naberius at 1:33 PM on April 19, 2017 [1 favorite]

They had to use a wider lens for Hanzo's hitbox
posted by fullerine at 2:37 PM on April 19, 2017 [3 favorites]

Having played fighting games for over two decades now, these stir something deep on my soul at even a glance.

Although I do have to wonder why the one with the two copies of Kyo has different hitboxes on each. KOF XII vs. XIII?
posted by DoctorFedora at 3:49 PM on April 19, 2017

Having been familiar with the most primitive versions of these -- the hit zones from Asteroids and Space Invaders for example -- I was shocked to find around 2000 when I dipped my toe into the original Atari 2100 Stella programming scene that the 2100 had perfect collision detection; it could detect when any pixel of either missile or player was coincident with either other, and set a hardware register to reflect this. In these days of hardware accelerated 3D world creation I am mildly surprised that nobody has thought to go back to this particular basic.
posted by Bringer Tom at 4:47 PM on April 19, 2017

Bringer Tom, this is not uncommon on systems with hardware sprites. The Commodore 64 has this feature too, and is able to detect collisions with other sprites or backgrounds. It's an easy feature to provide at a basic level; whenever a pixel of both sprites and/or background are to be drawn at a particular point on screen so that the hardware has to decide which to output, that's when to declare a collision.

It turns out though that, often, you don't want bit-level, hardware level collision detection. If you're using sprites to supplement the background, those may raise false collisions. If not every bit of the background is intended to be collideable, you may run into problems. (The C64 actually only registers collisions with two of the four possible multicolor mode colors, perhaps because of this.)

Additionally, the C64 only registers which sprites are involved in a collision, not directly which sprites are colliding with which (which would require 64 bits to represent instead of 8). And sometimes you want to detect possible collisions, like if the sprite fell one pixel would it collide with a tile, for use in platforming ground detection.

All of these considerations limit the utility of hardware collision detection, while software collision detection can be fast and pretty accurate, if the number of objects to check are small or compartmentalized into regions.
posted by JHarris at 5:27 PM on April 19, 2017 [4 favorites]

so something I hope exists, but that I've never gone looking for, is a sort of "deconstructed" 2d fighting game where the characters are displayed as their hurtboxes and hitboxes and nothing but. piles of differently colored squares jabbing at each other, without any attempt at making them represent anything but what they are.
posted by You Can't Tip a Buick at 7:48 PM on April 19, 2017 [3 favorites]

Awww c'mon, they missed these.
posted by Jon Mitchell at 9:10 PM on April 19, 2017 [2 favorites]

Buick, in at least one of the betas of Pocket Rumble (which is due for final release Any Day Now), at least one of the unfinished characters existed primarily as a collection of hitboxes and hurtboxes. It was really hard to play as them, because it turns out that most of us just aren't ready for that level of abstraction!
posted by DoctorFedora at 11:04 PM on April 19, 2017 [3 favorites]

As far as I know, Reassembly has perfect hitboxes. The spaceships are constructed from simple polygon shapes so accurate collisions are a natural fit for the artistic style.
posted by foobaz at 9:23 PM on April 20, 2017

I've been seeing people doing joke hitboxes on Twitter using stock photography.
posted by RobotHero at 7:58 AM on April 21, 2017 [1 favorite]

Ha, that's great, RobotHero.
posted by cortex at 8:34 AM on April 21, 2017