Pixel Joint Forum: Lineart and "Jaggies"

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   Hey, I'm a beginner trying to get into pixel art and there was some questions I had concerning making a piece's outline. It's stated numerous times that one should avoid creating jagged edges on their outline, but I have issues judging what is considered jagged or not. While some atrocities are very apparent, sometimes I feel its hard to "pickup" on what's considered a proper line.

I've read this tutorial here: http://rjanes.com/tutorials/introduction_to_pixel_art.php

And it mentions that in general, only 5 "types of straight lines" exist (with a few exceptions I'm sure), and while its easy to grasp what makes a straight line straight, (using a consistent amount of pixels per "segment") I feel like this concept is harder to grasp with curves and more irregular lines. For example do ALL curves have to follow that format to look smooth? (without the use of AA)

Can anyone maybe give me more insight into this topic or point me toward a more proper article? Is there a good rule of thumb to keep in mind to easily keep lines non-jagged? Thank you.

Edited by xavier2 - 25 December 2014 at 9:34am

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xavier2 Seaman Joined: 06 December 2014 Online Status: Offline Posts: 4	Topic: Lineart and "Jaggies" Posted: 24 December 2014 at 10:42am
	Hey, I'm a beginner trying to get into pixel art and there was some questions I had concerning making a piece's outline. It's stated numerous times that one should avoid creating jagged edges on their outline, but I have issues judging what is considered jagged or not. While some atrocities are very apparent, sometimes I feel its hard to "pickup" on what's considered a proper line. I've read this tutorial here: http://rjanes.com/tutorials/introduction_to_pixel_art.php And it mentions that in general, only 5 "types of straight lines" exist (with a few exceptions I'm sure), and while its easy to grasp what makes a straight line straight, (using a consistent amount of pixels per "segment") I feel like this concept is harder to grasp with curves and more irregular lines. For example do ALL curves have to follow that format to look smooth? (without the use of AA) Can anyone maybe give me more insight into this topic or point me toward a more proper article? Is there a good rule of thumb to keep in mind to easily keep lines non-jagged? Thank you. Edited by xavier2 - 25 December 2014 at 9:34am
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eishiya Commander Joined: 04 August 2022 Online Status: Offline Posts: 1109	Posted: 24 December 2014 at 10:55am
	The general rule in avoiding jaggies in curves is to not mix short and long segments at random, but rather to have them increasing OR decreasing in length consistently, e.g: Smooth: longer - longer - longer - shorter - shorter - shorter Jagged: longer - longer - shorter - longer - shorter - shorter It's also important to keep in mind how much longer/shorter the segments get with each step, the change amount should also be constant or constantly increasing/decreasing, not random. You also want to avoid drastic changes in the length (e.g. going from 1px segments to 4px segments with no in-between). Fortunately, jaggies are something that stands out if you have them, so it's easy to tell when you've done a good enough job of smoothing them. Like all things in art, jaggies are just something to be aware of, not something to always avoid. Using "jagged" lines carefully can give you shapes that are subtly textured and feel more organic than smooth curves. Jaggies are only a problem when a smooth curve is expected. Edit: If you want people to take a look at your art and give you feedback, you should post in the WIP section, not here. Edited by eishiya - 24 December 2014 at 10:57am
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xavier2 Seaman Joined: 06 December 2014 Online Status: Offline Posts: 4	Posted: 25 December 2014 at 9:38am
	Thanks. I've removed my log atrocity per your request. A quick question though: a lot of people refer to creating a line as an aspect ratio - like 2:1, or 1:2 etc. For some reason I'm having issues understanding it. It seems like some sites refer to it differently, or maybe I'm just not getting it. A 2:1 line for instance is suppose to 2 pixels right/left, then you move up/down 1 pixel and repeat? Yet in the example link I gave in my first post, the guy has 3/4 listed, but it works differently to the 2:1 line, where it looks like he's only going over 1 pixel? Any quick insight on that? Thank you.
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eishiya Commander Joined: 04 August 2022 Online Status: Offline Posts: 1109	Posted: 25 December 2014 at 10:56am
	3/4 refers to it being 3/4 of 90 degrees (he calls the fractions in the diagram fractions "of a right angle", but that's easy to miss in the text), but I think referring to them like that is bound to lead to confusion since fractions usually represent slopes, not fractions of a specific angle. The actual angles and slopes in the diagram are: "0": 0 (no slope) "1/4": ~26.56 degrees (slope 1/2, one pixel up/down for every two pixels over) "1/2": 45 degrees (slope 1, one pixel up/down for every pixel over) "3/4": ~63.44 degrees (slope 2, two pixels up/down for every pixel over) "1": 90 degrees (infinite slope, vertical line).
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