Why do many high-color consoles still use generous amounts of dithering?

[Joe Redifer]

Everyone hates the Genesis and it's crappy graphics.  It has to use dithering to "fake" colors it doesn't have because it is a complete piece of shit.  OK I am exaggerating, but if you have the colors, why not use them?  I see this a lot on the Turbo/PC Engine, SNES, Neo Geo and arcade games.

Here's Fatal Fury 3 on the Neo Geo:


Notice that it has dithering to help with the gradients on the floor.  SNK never tried to be conservative about memory usage and the capability was there, so WTF?  Why use dithering which makes the image look less smooth, especially when all MVS's were hooked to an RGB monitor in an arcade making the grainy dithering stand out like a severely infected thumb?  This was even way more prevalent in early Neo Geo releases like Nam 1975.  Is there some kind of limitation somewhere that we don't know about?  I can see no other reason to use dithering as it doesn't really look very good artistically.  I can find many more examples if need be.

[nat]

I've noticed this a lot on TurboGrafx games too, like you mentioned. I've always kind of wondered about that, especially in games that definitely weren't pushing the color count limit by any stretch of the imagination.

[Turbo D]

I always assume that it is lazy programmers or ones that have poor skill/software to work with. The genesis and pce both have masterpieces and crap to look at.

[Keranu]

As mentioned in another thread, a little dithering doesn't hurt, like in this case. From what I know, Neo Geo has the same 16 colors per sprite/tile like the other 16-bit (and 32-bit?) consoles, which might play a role in this case, but it doesn't look like it from the screenshot. Good observation.

[guyjin]

I think it might be that pixel artists are (or were) used to dealing with dithering, and so did it out of habit when they had no need. That or it's easier somehow.

[Joe Redifer]

The Neo Geo can put 4096 colors on screen at once out of 65,536 colors.  Thems a lot of colors!  There are only 226 or so colors on that Fatal Fury pic.  Thousands of colors to spare no matter which two characters are on screen.  I don't even think that laziness is a factor.  Wouldn't be easier (and lazier) to select a single solid color than to create a dithered pattern to use?  Maybe the dev system sucks and doesn't let developers use the true power of the machine?

[Joe Redifer]

OK here's some more (sorry if it seems like I'm picking on the Neo Geo exclusively, I'm not trying to):



It looks the worst on sky gradients (reminds me of the Genesis version of Altered Beast).  I am not expecting the sky to be completely smooth from top to bottom without any "bars", that's cool.  But the dithering really leaves me confused and does not help make anything smoother, especially when used in the skies.  They would look better as the solid color they are trying to fake.  It almost seems as if they only had 3 or 4 shades of purple to work with on the road on the first stage of Last Resort.

[Bonknuts]

 Well, you can't just take colors per screen as the measurement. That only works for bitmap displays (like PCs and MACs), not tile based displays like the NeoGeo and other consoles. For tile based displays, it's the number of colors per tile + the number of palettes available.

 For the NeoGeo it's a sprite based system only (with the exception of a single not scrolling window frame). Sprites are used to build the BG layers. Each 16x16/16x32 sprite can only access 16 colors with one color being unchange able(for transparency). The system has 256 palettes (and an altered bank of 256 palettes which you can switch, but not sure if this is mid screen or during vblank) - each palette entry is 32 reds, 32 greens, 32 blues for a total of 32k color master palette. So you have 3840 colors in 256 palettes from 32k of colors, with each 16x16/16x32 accessing 15 colors.

 That's one reason for dithering, the other reason is that it adds "texture" to an image. SNES was guilty of pillow shading and looks kind of fake, dithering helps break that up. Dithering works great for colors/hues that are close together and the NeoGeo games look great with it IMO. Dithering on the Genesis stood out more and a lot of times looked terrible because the dithering between colors/hues were too great in difference.

[Joe Redifer]

Dithering works great for colors/hues that are close together and the NeoGeo games look great with it IMO.

I agree, like in the case of the reds in the Metal Slug title screen.  But I think skies should be smooth.  The floors in Fatal Fury 3 look fine.  Anyway thanks for explaining that, I knew there must be a reason.  I would think that having more than 16 colors per sprite would be something someone would think about when designing the system.

[Keranu]

Good answer, mal. And yeah, that sky in Neo Turf Masters does look pretty bad!

[grahf]

...the other reason is that it adds "texture" to an image.

Exactly what I was going to say. In that particular shot it gives the screen a rough natural look, instead of looking like plastic. I suppose like all things, it doesnt always look as intended in "real life" as it did on the devs machine.

[Black Tiger]

Dithering is an art style like cross hatching. It doesn't have to only be used for super low color graphics. I like the look of well done dithering no matter how low or high color the game is.