Help me with AA!
Printed From: Pixel Joint
Category: The Lounge
Forum Name: Resources and Support
Forum Discription: Help your fellow pixel artists out with links to good tutorials, other forums, software, fonts, etc. Bugs and support issues should go here as well.
URL: https://pixeljoint.com/forum/forum_posts.asp?TID=15316
Printed Date: 13 September 2025 at 5:17am
Topic: Help me with AA!
Posted By: Buddy90
Subject: Help me with AA!
Date Posted: 24 October 2012 at 11:21pm
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OK, so I still don't think I know how AA works. I've been working on a lot of 4 color sprites recently, and I'm noticing that what I'm trying to do as AA isn't smoothing the object. Here's a simple ball, with simple AA on it. How can I make look smoother, with only those 4 colors? I would like to keep the black outline.  ------------- http://ps3trophycard.com/profile/vilocon"> 
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Replies:
Posted By: neota
Date Posted: 26 October 2012 at 12:55am
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AA is a mathematical function (roughly equivalent to a 'box filter') for
simulating sub-pixel detail (having a shape 'partially cover' a pixel).
the pixels of the line/shape you are antialiasing can be considered as
plotted with a given opacity (say you're plotting black on white --
black pixels would be 100% opacity, white 0%, mid-grey 50%), according
to how much of the infinitely-precise shape you are trying to represent
falls into that pixel. Generally the other important framing device is priority: you are always antialiasing one line or shape onto another, so you have to decide which one is in front. More direct instructions: Imagine you have gridded paper, and draw a filled silhouette on it. The opacity of each pixel is equal to the proportion of black in the grid cell. That's the basic idea that you can get a sound theoretical understanding from -- Go play with some gridded paper and translate the shapes into greyscale pixel art. After that there are the questions of workflow and the more technical details of how eyes work that prescribe the avoidance of certain patterns and clusterings, which patterns can be usefully exaggerated, and why the '50% mix' of two colors is often not a straight averaging of their RGB values. For those aspects, on Pixelation you can find several tutorials, plus Helm's 'ramblethread'. My advice though is to only think about that stuff after you really have a good grasp on the -basic- techniques. ------------- absolutely. |
Posted By: cure
Date Posted: 26 October 2012 at 4:14am
This image by Ptoing seems relevant.
Antialiasing the border of an object that already has a black outline can sometimes be tricky if one wants to maintain consistent thickness in the outline. |
Posted By: Buddy90
Date Posted: 26 October 2012 at 4:53pm
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I'm still not sure I understand... I have seen that image from ptoing, but I can never make my lines appear smooth, they just look banded or blurry. Maybe I should give you a better piece, here is one I made with a little AA. Is what I'm trying to do as AA working?  ------------- http://ps3trophycard.com/profile/vilocon">
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Posted By: cure
Date Posted: 26 October 2012 at 7:02pm
| more or less. in some places you have 'AA banding' (refer to Helm's ramblethread or the pixel art tutorial if you're unfamiliar with the term), and sometimes it is necessary to AA into a line rather than just have AA hugging the line. also make sure the lengths of your AA are optimal, it's a common mistake to use a single dot of AA where a short line (2 or 3 pixels) would better ease the transition. in the purple pokemon picture, it would be good to have a darker color to ease the jaggies on the back of the tongue and AA into lines where necessary. shading the outline (dark purple instead of black where the outline is around a light area) can also help. |
Posted By: Buddy90
Date Posted: 26 October 2012 at 7:50pm
OK, I gave it another shot. I think it looks smoother now. ------------- http://ps3trophycard.com/profile/vilocon">
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