A question about 2D sprites

[Angelcurio]

First of all, good day.

I have a question in my mind since a couple of years and i hope that someone can help me with it.

What exactly makes a 2D sprite look good in one system, and awfull in another one?

I wanted to know this, since after playing Marvel Vs. Capcom 2, i was extremely surprised about how ugly it looked on ps2 compared with its dreamcast counter part.

The final boss of that game, it looked excellent in dreamcast, but in ps2 it looked like if it were a lower resolution pic, with its body extremely pixelated, and also hard edges in all its body, when in dreamcast it had very soft edges and didnt look pixelated or like if you were watching a pic with the resolution set in 320*240 with 24 colors.

I hope you can clarify this to me. Sorry for my bad english, since it is not my real language.

PS: Can AA be applied to 2D games? or is there some kind of filter that can eliminate those hard edges?

Sorry if one of those questions is a little dumb or silly, but i am not a tech guy.

Thanks in advance.

 

[darkblu]

two things affect 2d sprites: quality of the source and precision of the reconstruction method. quality of the source can be further decomposed into spatial resolution and color fidelity. and reconstruction basically constitues to the choice between point- and bilinear sampling ; ) oh, and presence or absence of alpha blending : )

 

[Shifty Geezer]

Regards 2D on different machines, I can't say. I presume both varieties are implemented as 2D draws rather than 3D sprites and I don't know what limits there'd be.

But for AA on 2D, yes it's possible. Assuming you mean specifically 2D images as sprites, you can create these with alpha-blended AA edges. This adds an extra blending process to the draw, where writing a pixel isn't a case of just copying a value to it, but instead interpolating the current pixel colour with the new pixel colour based on alpha value. This was way beyond old 2D consoles, but modern machines with plenty of framebuffer bandwidth can cope. I can't say I've seen it used anywhere outside of the PC though. PSP and DS 2D games are still jaggified I think. You can also draw in vector graphics for 2D and add an AA process, like Flash in high quality versus low quality.

 

[Angelcurio]

Regards 2D on different machines, I can't say. I presume both varieties are implemented as 2D draws rather than 3D sprites and I don't know what limits there'd be.

But for AA on 2D, yes it's possible. Assuming you mean specifically 2D images as sprites, you can create these with alpha-blended AA edges. This adds an extra blending process to the draw, where writing a pixel isn't a case of just copying a value to it, but instead interpolating the current pixel colour with the new pixel colour based on alpha value. This was way beyond old 2D consoles, but modern machines with plenty of framebuffer bandwidth can cope. I can't say I've seen it used anywhere outside of the PC though. PSP and DS 2D games are still jaggified I think. You can also draw in vector graphics for 2D and add an AA process, like Flash in high quality versus low quality.

Thats also another thing that has been circling my mind for a long time. As you said, current systems enjoy a lot of framebuffer bandwitch, and yet the vast majority of 2d fighters have a lot of jaggies. What could be the cause of this? Could it be some kind of technical limitation or laziness of the developers?

So far, if my memory serves me right, guilty gear is the only 2D fighter that is jaggies free. Also, not quite sure on this one, i have the impression that dreamcast games had less jaggies than in any other current gen console, what coud be the reason behind it?

 

[Shifty Geezer]

Thats also another thing that has been circling my mind for a long time. As you said, current systems enjoy a lot of framebuffer bandwitch, and yet the vast majority of 2d fighters have a lot of jaggies. What could be the cause of this? Could it be some kind of technical limitation or laziness of the developers?

I don't know how 2D blending is performed on these consoles. If it has to be done on the processor, it could still be limited. They're designed for 3D engines and may have had high-end 2D support left out. If however you can use the graphics pipeline to copy over your 2D sprites and alpha blend, the reason it's not used has to be a shortcoming by the developers. I would recommend they create the sprites very large and downscale to add supersampling quality, and make a suitable mask that antialiases the edge. I have no idea why this isn't the case. But what was the last 2D game to be produced? Maybe they were using production methods carried over from older tech rather than updating the production process?

 

[Tagrineth]

2D sprites can be rendered as "3D" objects for easy AA - check out Ogre Battle 64. Even the N64 was capable of (blurred to hell) AA'd "2D" sprites.

 

[Angelcurio]

I don't know how 2D blending is performed on these consoles. If it has to be done on the processor, it could still be limited. They're designed for 3D engines and may have had high-end 2D support left out. If however you can use the graphics pipeline to copy over your 2D sprites and alpha blend, the reason it's not used has to be a shortcoming by the developers. I would recommend they create the sprites very large and downscale to add supersampling quality, and make a suitable mask that antialiases the edge. I have no idea why this isn't the case. But what was the last 2D game to be produced? Maybe they were using production methods carried over from older tech rather than updating the production process?

Someone lent me the japanese version of King of Fighters XI for ps2, i guess it was released a couple of months ago. And it has jaggies, but back in dreamcast days, the Kof titles that they released (at least 99 dream match and 99 evolution) did not have jaggies.

The same goes with marvel vs capcom in dreamcast and ps2. Only the ps2 version has jaggies.

At first i thought that it could be developer lazinezz, but after checking the game, i saw that it is using higher resolution sprites, but with jaggies.

But then another question arises. If its a techical limitation, then why all the Guilty Gear games released across all consoles always are jaggies free ?

 

[Fafalada]

Could it be some kind of technical limitation

2d games haven't been technically limited since about 1999 (on consoles).

Anyway darkblu answered this already, but to reiterate - sprite graphics aliasing is at the source level - ie. if you want nice AA, it's up to the artists that draw the bitmaps.

2d vector graphics(for instance, LocoRoco) are another matter - and they can use the same AA techniques as other 3d rendering (in fact they can use some better - like edge AA).

 

[Lazy8s]

The Guilty Gears are an exception because their source artwork was formated to take advantage of the 640x480 modern display, while many longer-running 2D franchises were originally targeted at lower resolution displays.