AuthorTopic: NEW CLUSTER STUDY THREAD!  (Read 45837 times)

Offline Helm

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NEW CLUSTER STUDY THREAD!

on: December 18, 2013, 08:46:04 pm
Alright, this time for something a bit different.

I think I've honed in on the best possible challenge to learn good pixel art regardless of the style you want to employ.

I want you to pixel something (or take something you've pixelled before and fix it) and to make sure there are no stranded pixels in the image.

What do I mean by that? I mean that if there's a pixel of a specific color in your image, then there should be at least one adjascent pixel of the same color directly connected to it. I will accept 45 degree connections, but they should not be your only tool in solving the situations they come up.

I strongly suggest a small palette because you'll lose your mind if you try this directly with something that has 32 colors or whatever.  And I strongly suggest trying to represent a fairly realistic character or item to get the most out of this excercise. Be brave.

As usual, avoiding banding of any type is your primary priority. It's very easy to solve any stranded pixel situation if you're just free to band everywhere, after all.

Today at work I created a piece with very few single pixels and it suddenly clicked, for me. I've been pixelling for close to 20 years and only now it clicked for me, it's kind of ridiculous. Please try it.


P.S. I will accept single pixels only if you can explain the reasoning behind using them (and "it was too hard to find another solution!" isn't a good explanation).  For example, a specular highlight can not always be solved as 2x2 pixel or a 2x1 pixel. In those cases, use them, but they should be very few. Don't let yourself off the hook easily.

I don't have any art that I can show you because I pixel professionally for 8 hours a day now but if you're really serious about bettering yourself, give it a shot.

We'll discuss your findings as you post them.

Offline r1k

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Re: NEW CLUSTER STUDY THREAD!

Reply #1 on: December 18, 2013, 09:00:56 pm
glad I decided to check pixelation before I went back to work on my commissions.  Ill try to apply this practice to my work right now, though I wont be posting the result since its part of my work.  Anyways Ill look foreward to seeing the discussion in this thread.

EDIT: ok after cleaning up 2 frames of my sprite, the areas I find difficult to do this are outlines, and AA.  Outlines because of areas with 45 degree angles.  Even though 45 degree connections where allowed, but I tried to find other solutions.  And AA where sometimes you just want 1 pixel of AA like near a corner.
« Last Edit: December 18, 2013, 09:38:04 pm by r1k »

Offline Vagrant

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Re: NEW CLUSTER STUDY THREAD!

Reply #2 on: December 18, 2013, 09:55:31 pm
What?

But isn't this impossible? What about 2:2 pixel line Anti alias? Are we allowed to do that?



Challenge accepted, nevertheless.
« Last Edit: December 18, 2013, 10:08:32 pm by Vagrant »

Offline Helm

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Re: NEW CLUSTER STUDY THREAD!

Reply #3 on: December 18, 2013, 11:14:27 pm
If you want to anti-alias, better do it at an angle where two pixels or more would make sense!

You will never feel your clusters burning as much as when you simply can't do one-point antialias to fix every little thing by implying subpixels.

edit: about outlines, you can use 45s but do consider a 'jagged' outline, especially when you round a curve. I used to hate jaggy outlines (like, full staircase step jaggies) before, but they seem like such stronger clusters now instead of straight up outlines all over. But yes, for outlines it's an acceptable choice to use 45 degree connections - as I said I want this excercise to be style-transparent and I can't take one-pixel-outlines away from people and claim that it is.

Just keep it in mind generally: a single-pixel outline is banding by itself.

edit edit: just to clarify so the above statement doesn't seem like crazy-person-talk, a single pixel outline is banding only in implication, via negative space. It takes a trained eye to look at pixels like that and I'm not saying anyone will care.



I'm just saying, it's worth thinking about.
« Last Edit: December 18, 2013, 11:26:05 pm by Helm »

Offline Vagrant

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Re: NEW CLUSTER STUDY THREAD!

Reply #4 on: December 18, 2013, 11:55:17 pm
Professor Helm

(New)

(Original)


Here's an animated comparison gif.




...And here is where I couldn't help but break the rules.  :-[



I might have missed some stray pixels here and there, but that's not a problem as I can go back and fix them. The ones in red are the ones I left there intentionally, because even tweaking a single pixel around facial features can radically change the original 'feeling' of a face; and I didn't see any alternatives.

This thing really made me think. It feels like a puzzle game. I had to get creative on the right cheek and even add hair there so I could lawfully anti-alias that line, and say GTFO to the jaggies there.
« Last Edit: December 19, 2013, 12:00:35 am by Vagrant »

Offline Cyangmou

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Re: NEW CLUSTER STUDY THREAD!

Reply #5 on: December 19, 2013, 02:15:55 am
Helm,
Some questions regarding to your working specs

I mean there are dither gradients which feature single pixels for the gradient. I am not only talking about the 50:50 checkerboard pattern, but also various other dither style feature single pixels as part of the well-sorted pattern.

Also how will this technique work stylewise if you are using shaded 45 lines where each single pixel will get one shade darker (bits and pieces of the chainmail)

I mean, I understand what you are trying to bring across, however I think what you are saying is heavily limiting you, especially if you are intentionally try to use banding and blurring to your advantage (the given example uses blurring gently outside the focus and far in the back to improve the depth) and as well as strongly used single pixel detail can get a necessarity for realistic textures here and there.
 
I'd say the more bigger, realistic and color-amount intensive you go with your style the less single pixels are mattering - there it's enough to get your big clusters right to show that you use clusters for defining your planes.
For realism or hyperrealism although you sometimes have to break good cluster theory in order to get effects working. Fully detailled realisms are to a certain degree "gritty"

For gamesprites and for simplified or "cartoony-colored" or "restricted-value-modeled" stuff - I underline your statement.

However I am not to fond that it works with every style, since you are explaining in my eyes a style-brick on it's own. 2:1 specular highlights also could be an interesting style decision on their own.


single pixels are everwhere
-mothholes in the cape
-texture gradients in the tree texture of the midground
-rivets (2x2 ones feature 4 "banding-aligned" signle pixels
-at the tail of flowing dither clusters (single 50/50 dither pixels in the water and the foreground tree bark)
-blurred half-sunken dirt stuff in the water
-small detail subpixel areas for detailling out lower res (nose)
and as well some not fully polished or just forgotten pixels as well - but I think the example serves it's purpose and shows up some interesting points.


I think it's debatable if heavily restricted cluster usage makes your pixels better.
As long as you use your clusters as value and plane definition I think you nailed the purpose of using them.

For every a bit more complex shaded piece it will get extremely difficult and time-consuming to get rid of every type of banding - and most-probably people who haven't calibrated their eyes to pixel technique most probably won't even be able to tell the differences.

I mean it's an interesting approach, but if you could provide some examples it'd help a leot for understanding you ( I am not 100% sure if I got everything you wanted to share)
"Because the beauty of the human body is that it hasn't a single muscle which doesn't serve its purpose; that there's not a line wasted; that every detail of it fits one idea, the idea of a man and the life of a man."

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Offline Helm

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Re: NEW CLUSTER STUDY THREAD!

Reply #6 on: December 19, 2013, 07:51:02 am
Vagrant, there are still so many single pixels in that image! Do a second pass. I can spot dozens just by looking at it for a few seconds. That's part of the excercise, to look at it and train yourself to see the pixels.

Cyangmou,

1. yes, I am saying to avoid any dithering that creates single pixels. If one has a reason they absolutely need a dither pattern, they should explain what it is
2. if you want to do chainmail and can't find a way around it, do chainmail like that, but I bet there are other solutions to that textural problem if one tries hard enough
3. I do not believe banding can be used to one's advantage. Blurring will necessarily create *some* banding, but it should be minimized. I think it's completely within the scope of the excercise to do a blurred background like in your (awesome) image and have no banding or single pixels. It's just hard.

I am not saying everybody should do this for every piece of pixel art they produce. I am saying it's a worthwhile excercise

4.  I'd say the more bigger, realistic and color-amount intensive you go with your style the less single pixels are mattering - that is correct. And the less the piece benefits from being made with pixel art technique on the whole. On big, demosceney type pictures, I would expect the artist to show their pixelling in a few areas and do other areas much more vaguely and cgi-like.

5. I take your clarification in stride, even if we can't loudly proclaim that this excercise works for every style, it's still a valuable one to do, I think.

As to your image,  I wish I didn't have a dayjob, I'd sit and solve most of it and then we could discuss what is gained/lost by reshuffling the clusters. Select at least part of the image and try it, if you get the time. Don't just tell me why it can't be done, try to do it.

6. "I think it's debatable if heavily restricted cluster usage makes your pixels better.
As long as you use your clusters as value and plane definition I think you nailed the purpose of using them."

I think it's one thing to do that, and another to spend some time solving the 'puzzle', as Vagrant put it above. It gets you to a different mindset.

7. "For every a bit more complex shaded piece it will get extremely difficult and time-consuming to get rid of every type of banding - and most-probably people who haven't calibrated their eyes to pixel technique most probably won't even be able to tell the differences."

As with any involved finish in pixel art, the effect would be subconscious on the viewer.

I'll try to show something after work

Offline Cyangmou

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Re: NEW CLUSTER STUDY THREAD!

Reply #7 on: December 19, 2013, 12:34:04 pm
Helm,

Quote
I am not saying everybody should do this for every piece of pixel art they produce. I am saying it's a worthwhile excercise

I agree with that. The ultimative question is however what we gain from using it, where it's more powerful and where it just sucks in terms of efficiency. I am interested in finding that out.

Quote
1. yes, I am saying to avoid any dithering that creates single pixels. If one has a reason they absolutely need a dither pattern, they should explain what it is

I love to use dither pattern for various things
amongst others:
-soft light illustration (low-mid contrast diher patterns, just to show another kind of light)
-high res depth of field (low-mid contrast)
-low contrast gradient smoothing (low contrast)
-illustrating gritty textures (sand, gravel, other stuff depending on distance) (mid-high contrast)
-detail with a different color on a plane (rust, moss, ...)
-for blending clusters on top of clusters together

some of those effects can't be achieved with "blobby non-banding" cluster styles. But that's a choice you usually do if you start with adding dither.

I don't think that single pixels are bad or dither patterns, for me the key isn't cluster sharpness, it's the contrast. Low contrast single pixels don't hurt the eye.
On my new IPS Panel screen you can see the single of a low contrast dither gradient if you heavily focus those, otherwise it will "feel" like any other gradient.
There is the certain point in contrast where the effect tilts. But you can also tilt it effectively in order to show it's pixel art.

Quote
3. I do not believe banding can be used to one's advantage. Blurring will necessarily create *some* banding, but it should be minimized. I think it's completely within the scope of the excercise to do a blurred background like in your (awesome) image and have no banding or single pixels. It's just hard.

There we disagree. Blurring can definitely have effects of how to improve your image - lots of it is simple not worthwhile to do with pixel art or isn't achievable with low-res pixel art. But there are ways to use it, or at least I tried it and I think it's an valid alternative.
For a pixel artist the effect of blurring won't work, because he searches initially for clusters, for any other person looking at the image it will subconsciously be connected to an impression.
 
Minimize the"banding" never hurts.

It's definitely possible to do the blurred background in my image without any single pixels. The easiest way to achieve the same effect is simple with more colors.
I went there with dither and lower color to emphasize that it's pixel art.
Pixel artists always try to keep their palettes small, for better control over visual effects. But I think you have to choose between those 3 if you want to have fake gradients in your style:
-color count
-cluster sharpness
-dither

If you don't intend to have gradients the question won't occur anyways.

Quote
5. I take your clarification in stride, even if we can't loudly proclaim that this excercise works for every style, it's still a valuable one to do, I think.

As to your image,  I wish I didn't have a dayjob, I'd sit and solve most of it and then we could discuss what is gained/lost by reshuffling the clusters. Select at least part of the image and try it, if you get the time. Don't just tell me why it can't be done, try to do it.

The exercise is definitely valuable, no doubt.

I also don't claim that my example is the perfect solution regarding to style, cluster usage and how I solved various problems, but at least there are some underlying patterns and I can at least state what I tried to achieve in every place with various techniques.
It's already old, I moved on and would solve some things differently.
I am thinking a lot about how to use pixels to your advantage - a discussion in this direction could get interesting.

Quote
6. I think it's one thing to do that, and another to spend some time solving the 'puzzle', as Vagrant put it above. It gets you to a different mindset.
Knowing how to use clusters is a basic technique for pixel art, if not the most important technique and everyone who does pixel art should think about it during his creation process.
However you can band and break rules in art to your advantage and create different rules this way.

I mean I also break perspective or in order to get a more beautiful looking cluster or a "clean" line, but you can also do it the other way. Depends on what someones eye is calibrated to.
The pixel artist says: use clean line
The illustrator says: correct perspective is more important


Looking -forward to see what you are showing.
For this years Secret Santa I have made a piece with different focal style choices - we can discuss that one later too if you are interested.
« Last Edit: December 19, 2013, 12:48:24 pm by Cyangmou »
"Because the beauty of the human body is that it hasn't a single muscle which doesn't serve its purpose; that there's not a line wasted; that every detail of it fits one idea, the idea of a man and the life of a man."

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Offline Vagrant

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Re: NEW CLUSTER STUDY THREAD!

Reply #8 on: December 19, 2013, 03:42:03 pm
Helm,

Quote
I am not saying everybody should do this for every piece of pixel art they produce. I am saying it's a worthwhile excercise

I agree with that. The ultimative question is however what we gain from using it, where it's more powerful and where it just sucks in terms of efficiency. I am interested in finding that out.

I agree. It is a tad time consuming -having it done myself-, and the only noticeable visual difference I've seen is that I have now more jags, and more limitations regarding small complicated areas that use multiple colors, like eyes.
Not to mention any line that is not a 'perfect line' (1:0 straight, 1:1 diagonal); you have to go really flexible and change plenty/re-work just to attempt to AA on anything that's 2:1 or god forbid, more.

Can't wait for an example.


Edit: I made a small 32x32 tree last night that I can apply this practice; see how it works.
« Last Edit: December 19, 2013, 03:44:17 pm by Vagrant »

Offline Lanarky

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Re: NEW CLUSTER STUDY THREAD!

Reply #9 on: December 19, 2013, 09:21:43 pm


I attempted to find all of the single pixels in Vagrant's image, and highlighted them in blue. I am pretty sure I found all of them, but I only spent around 5mins looking for them. I did this purely for the practice of spotting pixels that are out of place, and I figured that I'd post it (with permission) for other to learn from.

I can see how looking for them will let you navigate your work faster, but I am not sure how the final product will turn out quality wise, as it is hard to attempt without a concrete visual example of what we are trying to do by achieving this. Your post on banding and clusters really helped me advance my work, so I look forward to learning more from this. Thanks.