General => General Discussion => Topic started by: Bkeegan on March 11, 2010, 03:37:52 pm

Title: Anti-Aliasing
Post by: Bkeegan on March 11, 2010, 03:37:52 pm
Hey Guys,

I was wondering if I could get some expert opinions. I had a question about anti-aliasing. I know I am going to incur some scorn when I describe how I have handled it. What I've done is create a new layer in the project file and then use the anti-aliasing line tool to create smooth outlines over my original artwork. This automatically utilizes transparency effects and when flatted introduces a handful of shades that were not manually chosen and thus I can see how it's not precise, which precision I am learning is a key principle in pixel art.

The method I use is incredibly fast and by using layers I can avoid mucking up my original art. I feel that I have been able to smooth over edges quite well using this.

So now for my question. I was wondering how the expert pixel artist on these boards handle anti-aliasing. What advantages do these particular methods have? Thank you for your time =)


Title: Re: Anti-Aliasing
Post by: Helm on March 11, 2010, 04:54:45 pm
The only problem with this is that it creates banding because the computer doesn't find it aesthetically displeasing. The only reason to do manual anti-alias is that reliably, your hands and eyes will do it better than the computer once you get used to it. Not that the computer can't do smooth, it can. In fact, that's all it CAN do. The less granularity, the more actual artistic choices in anti-aliasing by an active mind count. If you have 300 colors in a picture, chances are the computer will be able to make a smooth edge better than you. But what if you have only 3 colors, or 8, or 16? That's where pixel art techniques of manual anti-aliasing come into play, and they're more complicated than they look.
Title: Re: Anti-Aliasing
Post by: Mathias on March 11, 2010, 05:13:13 pm
Hey there, Bkeegan. Welcome. I see you haven't had the best introduction to this odd little place. Sorry about that.

OnTopic, though: The only reason I would "scorn" you is if you somehow forced me to use your method of AA, but you aren't and I'm therefore not personally affected by your decision. Ya know. We're all free to do whatever we want.

What program(s) are you using?

My biggest concern is that no machine automation can accurately AA your work for you, even if you define all edges manually by clicking point to point, tracing each sprite, etc. Your machine is still choosing what colors should go where. So you're robbing the finished product of being completely hand-crafted, and I'm sure the pragmatic AA pixel placement reflects this. AA'ing is an art in and of itself.

Secondly, yes, it's not precise. Your handing your palette over to your computer and saying, 'ok, have at it, make me some new colors!' When your computer doesn't know what's in the image (obviously). Hence, now you've got new shades in your finished product that are used only for AA. Not anywhere else. Logically, you would want to utilize these new AA auto-created shades elsewhere in your image - you can make smoother gradation between large areas of color, enhance depth, etc. The more you get into this type of hybrid technique, the more you step away from pixel art, and it's inherent benefits. Eventually, why not just go full-color and forget pixel art altogether?

And AA'ing your stuff isn't mucking up your work, it refines it. You could just as well manually AA on another layer, without the auto line transparency method. Using 100% layer opacity. This way you're protecting your palette. Surely, with this method of yours you have to do some manual clean-up anyway.

For the sake of the discussion, here's what I think you should do, and this will get you more feedback, for sure: post one your originals, with no AA, and then post the aftermath of your line tool technique being used to AA it. Having a visual to go along with this thread will help. I'm curious to see what you're pulling off, too.

Title: Re: Anti-Aliasing
Post by: Bkeegan on March 11, 2010, 10:07:27 pm

Yeah, it's cool though. Just shrugging it off and moving on.

I am using Paint.net which I am quite pleased with. I've tried other applications like promotion, graphics gale and grafx2 but I just don't like their interfaces. I like paint.net for the way the controls work more than anything else. (I did like grafx2's splitscreen zoom/normal view but I couldn't get over the lack of standard Windows undo/redo/cut/copy/paste controls)

I don't press a button and my entire image is AAed. I personally think the line tool in paint.net is stellar. When you draw a line it creates 4 drag points and you can move those around to shape the line as you see fit. What I do is create a layer and use this line tool. It does require carefully shaping and do I have to tweak the pixels afterwords. The aa line tool in paint.net creates semi-transparent pixels so technically it doesn't add new colors, just varying alpha levels of the color you picked. I suppose the new colors are created when the semi-transparent pixels are merged with whatever it happens to be in front of. I suppose it does automatically set the alpha level. I think that you'd have to use semi-transparent pixels if you wanted AA on anything that would be be placed in front a variable/dynamic background.

When I say that I do it on a separate layer so not to 'muck up' the original image is because I like to modularize my data and the layers allows me to manipulate the AA information separately.
Title: Re: Anti-Aliasing
Post by: Starscream on March 12, 2010, 08:50:57 pm

This is how I get my AA colors when I don't feel like guessing.
Title: Re: Anti-Aliasing
Post by: Jad on March 12, 2010, 11:25:44 pm
Just paint with one color on the other color with 50% opacity - voila - instant happy
Title: Re: Anti-Aliasing
Post by: 7321551 on March 13, 2010, 01:38:56 am
Although I think in some instances you can add some visual interest by manually choosing your color... particularly when gray is involved.
Title: Re: Anti-Aliasing
Post by: Bkeegan on March 13, 2010, 02:50:10 am
Just paint with one color on the other color with 50% opacity - voila - instant happy

Jad, yeah I was working on a piece today and that's what I ended up doing. It was actually faster than trying to use the pre-anti-aliased line too (and cleaner!)

Although I think in some instances you can add some visual interest by manually choosing your color... particularly when gray is involved.

Kinda makes the edge look sharp and crisp as opposed to a bit fuzzy.

I once read something about sub-pixel anti-aliasing, but it only works with lcd monitors. Apparently it feeds of the color and location of subpixels. You guys heard anything about that?