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Improve your pixel art sprites!

Introduction

In this tutorial, I will explain you how to use a couple techniques I used to improve Planet Centauri’s sprites before implementing them into the game (or before animating them).
Some of the rules shown here are very easy to use, and/or are purely  methodical;
so even if you aren’t very skilled, follow those simple guidelines to make your sprites cleaner.


Colors

A lot of basic mistakes will ruin the quality of your art.
Thankfully, they’re also generally quite easy to fix with some experience, and
by paying attention.


Too many colors

Pixel art is all about constraints. When two colors are very close, merge them into an intermediate one, so you see if it improves the result.
Using a small palette will help you improving your skills much more easily, and will make creating sprites also easier.
It also will make it easier to identify unwanted artifacts (i.e. misplaced pixels).


Gradients

If you are constructing a palette with gradients, avoid at any cost independent gradients (i.e. only dimmed/lighted base colors). Use gradients that depends on each other.

You can also try to use yellow-ish or cyan-ish saturated light colors, and blue-ish and purple-ish desaturated dark colors. However, avoid using an over-saturated or an under-saturated palette.
This usually ends up bad and breaks contrasts.
You should also use gradients with outspread tints to avoid washy color contrasts.

Remember never to use more colors than necessary, and use gradients with contrasted brightness.
Feel free to try using other generic palettes on your sprite to compare it with your palette so you can improve it.


Neighbor colors

Avoid as much as you can excessive contrasts between neighboring pixels.
For example, a black line over a white background usually won’t look natural.
A line that fits the background color well gives a realistic volume effect.

This is as true for outlines, which has to fit with both the inner color and the umbrage of the surface.

NB: Obviously, this doesn’t work with any graphic style.


Pillow shading

Pillow shading is a nasty effect that occurs when the light source comes from the front.

Avoid pillow shading, unless you really know what you’re doing.


Lines and curves

Perfect line: A line that has a constant vertical and horizontal step.

Perfect curve: A curve made of perfect lines which step always depends on the other parts of the curve.

Dirty line: A line that has at least one sub-segment with more than one adjacent pixel on one end.

As you may have noticed on the pictures above, dirty lines should be avoided.
You should use as much perfect lines and curves as possible.


Clusters

A cluster is a group, a pack of connected pixels with the same color.
Cluster shapes will greatly affect the final image.
Bony and crude clusters will give a sketchy aspect.
Round and straight lines are preferred so you get a precise, smooth and nice image.

Avoid lonely pixels. If one pixel is inside of a different color cluster without
any adjacent pixel with the same color, remove it.


Dithering et texturing

Contrary to popular belief, dithering isn’t as great as it seems. A lot of dithering between heavily contrasted colors will often give a dirty and noisy image.
It is also a very bad idea to use dithering when animating a sprite, because keeping coherent dithering will be awfully hard.

If you art style lets you do it, use texturing instead (the difference is that texturing does not induce color limitations).
But don’t forget, texturing means harder animation and worse clarity.
Again, it’s a matter of style.
If you want a cartoon-ish look, do not use dithering nor texturing.


Antialiasing

Antialiasing a technique that reduces the staircase effect (aliasing) which is clearly visible on two lines between two contrasted surfaces.

Internal AA

There are two use-cases for internal AA :
Simply separating two surfaces, and using lines or curves cutting through two different surfaces.

In the first case, you may just need to insert an intermediate color where aliasing is visible to reduce it (generally, when the curve abruptly changes).

In the second case, you may just need to add a small intermediate color cluster between every horizontal or vertical sub-segment.
Its size directly depends on the sub-segment size.


External AA

External AA suffers from an important restriction, unlike internal AA: The background color in a game will constantly change, so you need to have an effect that looks good on both dark and light backgrounds.

This rule is quite easy: You only apply the effect inside of the sprite.
The end of an outline that neighbors with the background should never be modified.

In this image, the internal AA effect applied on the outer part of the sprite unveils some nasty artifacts, while external AA, even if it isn’t as efficient, gives a great effect on any background type.


The end.

me: i love iphones! i personally prefer them to other phones :)

android user, teleporting literally next to me: um excuse me?? the new samsung galaxy alpha centauri s970 blood onyx edition is far superior to any apple product.. iphones killed my cat, steve jobs ruined my marriage, i get aroused at the smell of burning fumes,

Why would the sky glow red? An aurora! A solar storm in 2012, mostly coming from an active sunspot, showered particles on the Earth that excited oxygen atoms high in the Earth’s atmosphere. As the excited element’s electrons fell back to their ground state, they emitted a red glow. 

The sky that night, however, also glowed with more familiar but more distant objects, including the central disk of our Milky Way Galaxy on the left, and the neighboring Large and Small Magellanic Cloud galaxies on the right. 

Image Credit & Copyright: Alex Cherney (Terrastro, TWAN)

Here’s the labelled image for anyone who is interested:

Omega Centauri: The Brightest Globular Star Cluster : This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, Omega Centauri is the largest, containing over ten million stars. Omega Centauri is also the brightest globular cluster, at apparent visual magnitude 3.9 it is visible to southern observers with the unaided eye. Cataloged as NGC 5139, Omega Centauri is about 18,000 light-years away and 150 light-years in diameter. Unlike many other globular clusters, the stars in Omega Centauri show several different ages and trace chemical abundances, indicating that the globular star cluster has a complex history over its 12 billion year age. via NASA

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Planet Found in Habitable Zone Around Nearest Star

So this is kind of a big deal. Astronomers have just discovered a new planet orbiting the closest star to our Sun, Proxima Centauri. The planet is called Proxima b and orbits the star every 11.2 days. It has a mass that is estimated to be 1.3 times the Earth’s. Unlike the Earth, though, it’s only 7.3 million kilometers from the star—much closer than Earth to the Sun—but Proxima is so faint and cool it receives about two-thirds the amount of light and heat the Earth does. Essentially that means that it’s in Proxima’s habitable zone which opens the possibility of liquid water on its surface.

Researchers estimate that if the planet has an atmosphere (which isn’t confirmed), it may be between 86 to 104 degrees Fahrenheit on the surface. Without an atmosphere, it could be -22 to -40 degrees Fahrenheit. To put that in perspective, Earth would be -4 degrees if it didn’t have an atmosphere.

Before we go all Interstellar and have Matthew McConaughey check it out, though, it is 40 trillion km away, which means even the fastest ship would still take tens of thousands of years to get there! 

LEARN MORE (via Slate)

The Sombrero Galaxy and a Swarm of Globular Clusters

The Sombrero galaxy, or Messier 104, is a giant Sa type disk galaxy viewed from just above its equatorial plane and outlined by a prominent dark rim of obscuring dust. The central bulge is unusually bright and extended, and orbiting the galaxy is one of the largest known populations of globular clusters, containing up to 1900 members. In comparison our own Milky Way galaxy has only around 150-200 such clusters. Nearby prime examples of these are Omega Centauri, Messier 4 and NGC6752. 

Some of the Sombrero’s globulars are very large and one is classified as a separate Ultra Compact Dwarf galaxy, SUCD1, the closest known example of such an object. It is not known how the Sombrero amassed such a large number of globular clusters. This is normally a more typical feature of large elliptical galaxies. For example up to 12,000 globular clusters are orbiting the giant elliptical galaxy Messier 87.

The Sombrero Galaxy also contains a supermassive black hole of one billion solar masses - one of the most massive black holes among nearby galaxies.
The galaxy lies some 30 million light years away in the direction of the constellation Virgo.

Credit: Rolf Olsen

The W in Cassiopeia : A familiar, zigzag, W pattern in northern constellation Cassiopeia is traced by five bright stars in this colorful and broad mosaic. Stretching about 15 degrees across rich starfields, the celestial scene includes dark clouds, bright nebulae, and star clusters along the Milky Way. In yellow-orange hues Cassiopeias alpha star Shedar is a standout though. The yellowish giant star is cooler than the Sun, over 40 times the solar diameter, and so luminous it shines brightly in Earths night from 230 light-years away. A massive, rapidly rotating star at the center of the W, bright Gamma Cas is about 550 light-years distant. Bluish Gamma Cas is much hotter than the Sun. Its intense, invisible ultraviolet radiation ionizes hydrogen atoms in nearby interstellar clouds to produce visible red H-alpha emission as the atoms recombine with electrons. Of course, night skygazers in the Alpha Centauri star system would also see the recognizable outline traced by Cassiopeias bright stars. But from their perspective a mere 4.3 light-years away they would see our Sun as a sixth bright star in Cassiopeia, extending the zigzag pattern just beyond the left edge of this frame. via NASA

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Sid Meier’s Alpha Centauri

There are a number of features that make the maps in SMAC more interesting than those in the earlier Civilization games. It uses height to make hills and mountains, for example, instead of them being tile-features. The special resources are distributed in more interesting patterns; the newly-introduced borders make the size of the map work better; and the native lifeforms are better integrated that the barbarians were (or are, for that matter).

But the map generator has two really interesting features that still set it apart from other Civ-style games.

The first isn’t a feature of the generator, per se, but greatly affects the meaning of the maps: the player can terraform the planet. And not just in little ways, like raising or lowering a couple of tiles, though you can do that too. A couple of the council resolutions can raise or lower the sea level across the entire planet. (Global warming from too many boreholes can also melt the ice caps to the same effect.) The malleability of the terrain makes it fairly unique among strategy games.

It can be a viable strategy to flood the map and drown your opponents cities, or to drain the ocean and march your armies across on dry ground.

The second is vital part of the generator: the landmarks.

When a map is generated, it scatters a number of prefabbed features on the planet. A few are mostly decorative, but most have an effect of some kind.

They owe a bit, I think, to the discoveries in Seven Cities of Gold (like the Grand Canyon) and the wonders in Civilization–the manual refers to them as “giant natural wonders of Planet”–possibly via Colonization, though at the moment I can’t remember if that game had any exploration bonuses for natural wonders.

The landmarks in Alpha Centauri are unique even when compared to the later Civ games that included similar features. They occupy multiple map tiles, sometimes forming significant strategic features on the map in addition to their resource bonuses.

Moreover, they help give the random maps structure. In contrast to the accidental chokepoints of earlier Civ maps, they have deliberate strategic importance.

The map generator as a whole is “spikier” than earlier random Civ maps. The landmarks make things a bit less fair but more interesting. There were a lot of high-value city-sites in Civ II because the even pattern ensured that they would be frequent and predictable, but there’s only one Manifold Nexus.

Which is not to say that it’s an absolutely dominant strategy: There’s enough landmarks overall that everyone should be able to claim one, if they work on it. But there’s plenty of other things going on, so you may have other priorities.

In the end, it is a good demonstration of how maps (and procedural generation in general) are much more interesting when they have outliers to act as landmarks and memorable setpieces.