Hello, this is my first article for Union VideoGame Forums and I must admit I am rather nervous submitting this piece for all the world to see. I decided to write about a form of art which has major colour and memory limitations. This art has still produced some amazing panoramas through various tricks and techniques; I am writing of course about rasterized and colour indexed backgrounds and graphics. English isn't my first language. Please bear with me if something doesn't read quite right. I hope you enjoy my piece.
In current times we are used to backgrounds being a skybox or even a full 3D environment with complete weather and lighting systems. It is hard to imagine how awestruck people could be for a well-designed rasterized background. Even for those that lived through these generations of consoles and home computers still have trouble imagining the virtual vistas of the time. Waterfalls being made possible due to colour-cycling and beautiful skylines all gave us a fantasy world to think about, as the artist worked with the limited resources that they had.
In the following article I would like to tell you about a few of those limitations and then give some examples of these graphical masterpieces.
Limitations:
The hardware led to some serious limitations for developers and graphic artists. Not only was there a limited amount of colour values you could use, but you could also only use a selection of these per palette and on top of that only a few of those per amount of pixels.
For instance, the ZX-Spectrum could only have two colours per 8 by 8 pixel block out a possible 15 colours. Eight colours with two intensities with black staying the same. The Commodore C-64 was far more capable as a system, but still only four colours for each 4 by 8 pixel title in a resolution of 160 by 200 pixels and two for an 8 by 8 pixel tile if you used the “high” resolution of 320 by 200 pixels. Yes that is 200p for those people counting
.
Now both used a palette of 16 colours but the C64's palette was a lot smarter in colour choice than the ZX-Spectrum. Not only did the ZX-Spectrum use two black values, the C64 had far more grey values and colours opposite of each other. This might not sound like a big deal now, but with old CRT sets and monitors you could use their limitations to create the illusion of more colours than the system officially supported. Take a look at the following link displaying pixel artworks running on a C64: http://c64pixels.com/main.php
On consoles things didn't fare much better. The Nintendo Entertainment System, NES for short, had 64 colours to choose from. However, because many colours were doubles, basically only 54 colours were available. Now on top of that there was a limitation of three colours for each 8 by 8 tile with the fourth colour being a transparent, with every 2 by 2 tiles sharing the same palette. This meant for a 16 by 16 pixel area you could only have three colours at your disposal.
On top of that these patterns had to be defined and there was a limited amount of tiles you could store. Luckily Nintendo made mappers to overcome this limitation and some of these mappers also added other features. Features like line-interrupts and split-screen scrolling to facilitate score sections and two player games. The MMC5 even added two extra pulse wave channels and another PCM channel. Unfortunately those where not used in the west as the NES did not allow for extra audio to be added to the signal.
Sadly only Nintendo made mappers were allowed in the west. This is sad indeed because some of the mappers Konami and Sunsoft made added some brilliant features. In fact the VRC7 added a FM chip that had almost all of the features the SEGA Megadrive/Genesis used. But that is for another article.
Things weren’t all doom and gloom. To save space the NES allowed for the inverting of tiles and sprites. Because of this they could be used again in a mirrored manner and thus save memory to be used for other tiles. Smart use of tiles meant you would be able to make one corner tile for all corners and just reuse it by inverting it either over the x or the y axis.
For those that love looking for missing Ps, get out your magnifying glasses! As the NES had a resolution of 256 by 240 pixels, 16 of those lines usually where not displayed on your average TV set. That's right, 16 Ps are missing! This meant that effectively you had a resolution of 256 by 224 pixels.
On to the Art:
Now that we've discussed some of the typical limitations of the time, it is a bit more accessible to understand the beauty. For my first example I wanted to point to Ninja Gaiden 2 for the NES and its beautiful city background:
As shown in the picture, there's only three shades of blue and a black background. As mentioned earlier the NES could only display three colours in its tiles with one transparent, yet they where able to create a beautiful inspiring cityscape in the distance. This was perfect for a Zeitgeist when nighttime in cities was a reoccurring theme for films and games. This cityscape made you feel like you where fighting on the tops of skyscrapers in some unknown metropolitan area, while coming to a climax in fighting a horrible mutant of a man to get on a train.
First stage of Ninja Gaiden 2
And that is not all--the lights even flicker. By a rotation of palette index numbers for the pixels in the tiles, the colour linked to that pixel would flicker as if the lights were switched on or off. This in turn increased the illusion of a bustling city and is a technique used by some to a point of genius.
The aforementioned train was your setup for the next level where you were treated to a real technical marvel for the time: parallax scrolling. By using the line interrupt feature of the MMC3, which was one of the mappers provided by Nintendo, the people at Tecmo added some nifty parallax scrolling to the game. While you jump from train cart to train cart with a mountain backdrop everything scrolls at different speeds thus giving the illusion of depth.
The way this worked was that after each scanline a counter would be increased in number by one. If this counter matched the preset number it would trigger an interrupt for the CPU to act upon. The MMC3 also allowed the programmer to set a new value and 'reload' this by command. This would cause the updated value to be loaded at the end of a scanline. It is for this reason that the stage was able to have different scroll speeds at different scanlines thus creating the illusion of depth. It was actually meant for split-screen games, but creative developers were able to use it for other purposes.
Second stage of Ninja Gaiden 2 With Paralax Scrolling
The earlier mentioned colour cycling technique was often used to create animation in the background. Each colour used in a tile stores as a number in a palette. By rotating these numbers it was possible to give the illusion of movement. This was often used for waterfalls, conveyer belts and rain. The technique was a lot cheaper for memory usage than storing different tile patterns for each frame of animation and could still yield stunning effects. A good example of this is Megaman 2.
In Megaman 2 the technique is utilized on almost every level: the conveyor belts of Metalman to the waterfalls in the background of Bubbleman and also the ice blocks of Flashman all where done with the cycling of colours. In fact, even the small bubbles you see every so often on the top of Bubbleman's stage are just pixels with the same index numbers as the ones of the waterfall, this created the illusion as where one in a giant aquarium tank with air blown into the water to prevent it from growing stale.
Megaman 2:Flashman stage with colour cycling used for the ice blocks
A compilation of Megaman 2 Cycling effects. Everything from the waterfalls, splashes in the water, Lava and bubbles are colour cycled.
This same effect was usually used to create the many flashing objects in Megaman and other games of the time; it's a very handy technique for developers allowing for animation otherwise not possible with the memory limitations given.
Colour knowledge and image build-up on old TV sets was often used in the advantage of creating illusions of more colours or animations. For example on old CRT televisions neighboring pixels and scanlines would often blend with each other. With these limitations a good programmer would be able to create the illusion of more colours or even some hints of “translucency” via a well-chosen dithering. This in turn also meant that one had to use clashing or very clear colour differences to create contrast for things that had to stand out. Things like the player or blocks to stand on were often designed in such a way that they would be clear to see even on the fuzzy screens of the day.
Not to be confused with colour bleeding, this detrimental effect could be seen in some ZX-Spectrum and MSX games where a pixel line of colours kept going because of hardware limitations. So for the next examples keep in mind that these games were designed to be shown on older TV sets and not on the 1080p monitors and sets we play them on now.
As a first example I would like to show the second level of the game Cyber Shinobi for the SEGA Master system. Although the gameplay of this game is hit or miss, with some finding it absolutely terrible, it was a personal favourite of mine while growing up. Especially the first stage which had these beautiful vistas drawn with the use of only a few tints of green and yellow.
In the distance you can see the other side of the harbour, possibly Hong Kong, in which you are fighting. The shimmering water represented by a few well-chosen dark green, light green, yellow and lighter yellow pixels, as where they reflecting the buildings in the distance. All the while most of the space actually remained black. The buildings themselves were brighter, more yellow, some red and light green, as if clearer to see but further in the distance than the water in which they were reflected.
The second stage of Cyber Shinobi. Although here pixel perfect, on a CRT TV of old the colours would be blended.
Simple as it may look here, it actually is not that easy to pull off without knowledge of colours and how they would refract in the water at night.
Another example of great background and level artistry is the sheer magic Konami was pulling out of the MSX 1. Like the ZX-Spectrum it was prone to colour bleeding and on top of that there was no hardware scrolling whatsoever, but games like the NEMESIS/Gradius series gave us beauties like these in full motion and often animated:
Organic Stage of Nemesis 2
Nemesis 3 Botanical stage
It wasn't just here that Konami was able to work magic, Castlevania 3 was able to use its own mappers. As mentioned earlier, Nintendo only allowed the use of their own branded mapper chips and lacked the ability to add sound channels. Although the MMC5 lacked some of the features present in Konami's own VRC6, it still was a sight to behold when playing it for the first time. The graphics only really started to shine in the later levels which even showed fog effects animating per line creating a creepy atmosphere. Or the rotating gears in a clock tower.
Western version of Castelvania 3's Clocktower.
Now with the brilliant pixel art of Konami I would like to end this slight lamentation of this art form and with some hope that I got some of the readers interested, if not hooked, to play these games for themselves. In any matter it was great writing about this subject as it is a section of pixel art often under-represented in an area of gaming where sprite art was stealing most of the limelight.
Just before I go I wish to share some links regarding the demo scene of the C64 and what great pixel art they have created over the years and a link of an artist, Mark Ferrari, who used to make backgrounds for games and now has some great colour cycled works of art posted on his web page. Thank you for reading!
http://c64pixels.com/main.php
http://markferrari.com/
In current times we are used to backgrounds being a skybox or even a full 3D environment with complete weather and lighting systems. It is hard to imagine how awestruck people could be for a well-designed rasterized background. Even for those that lived through these generations of consoles and home computers still have trouble imagining the virtual vistas of the time. Waterfalls being made possible due to colour-cycling and beautiful skylines all gave us a fantasy world to think about, as the artist worked with the limited resources that they had.
In the following article I would like to tell you about a few of those limitations and then give some examples of these graphical masterpieces.
Limitations:
The hardware led to some serious limitations for developers and graphic artists. Not only was there a limited amount of colour values you could use, but you could also only use a selection of these per palette and on top of that only a few of those per amount of pixels.
For instance, the ZX-Spectrum could only have two colours per 8 by 8 pixel block out a possible 15 colours. Eight colours with two intensities with black staying the same. The Commodore C-64 was far more capable as a system, but still only four colours for each 4 by 8 pixel title in a resolution of 160 by 200 pixels and two for an 8 by 8 pixel tile if you used the “high” resolution of 320 by 200 pixels. Yes that is 200p for those people counting
.Now both used a palette of 16 colours but the C64's palette was a lot smarter in colour choice than the ZX-Spectrum. Not only did the ZX-Spectrum use two black values, the C64 had far more grey values and colours opposite of each other. This might not sound like a big deal now, but with old CRT sets and monitors you could use their limitations to create the illusion of more colours than the system officially supported. Take a look at the following link displaying pixel artworks running on a C64: http://c64pixels.com/main.php
On consoles things didn't fare much better. The Nintendo Entertainment System, NES for short, had 64 colours to choose from. However, because many colours were doubles, basically only 54 colours were available. Now on top of that there was a limitation of three colours for each 8 by 8 tile with the fourth colour being a transparent, with every 2 by 2 tiles sharing the same palette. This meant for a 16 by 16 pixel area you could only have three colours at your disposal.
On top of that these patterns had to be defined and there was a limited amount of tiles you could store. Luckily Nintendo made mappers to overcome this limitation and some of these mappers also added other features. Features like line-interrupts and split-screen scrolling to facilitate score sections and two player games. The MMC5 even added two extra pulse wave channels and another PCM channel. Unfortunately those where not used in the west as the NES did not allow for extra audio to be added to the signal.
Sadly only Nintendo made mappers were allowed in the west. This is sad indeed because some of the mappers Konami and Sunsoft made added some brilliant features. In fact the VRC7 added a FM chip that had almost all of the features the SEGA Megadrive/Genesis used. But that is for another article.
Things weren’t all doom and gloom. To save space the NES allowed for the inverting of tiles and sprites. Because of this they could be used again in a mirrored manner and thus save memory to be used for other tiles. Smart use of tiles meant you would be able to make one corner tile for all corners and just reuse it by inverting it either over the x or the y axis.
For those that love looking for missing Ps, get out your magnifying glasses! As the NES had a resolution of 256 by 240 pixels, 16 of those lines usually where not displayed on your average TV set. That's right, 16 Ps are missing! This meant that effectively you had a resolution of 256 by 224 pixels.
On to the Art:
Now that we've discussed some of the typical limitations of the time, it is a bit more accessible to understand the beauty. For my first example I wanted to point to Ninja Gaiden 2 for the NES and its beautiful city background:
As shown in the picture, there's only three shades of blue and a black background. As mentioned earlier the NES could only display three colours in its tiles with one transparent, yet they where able to create a beautiful inspiring cityscape in the distance. This was perfect for a Zeitgeist when nighttime in cities was a reoccurring theme for films and games. This cityscape made you feel like you where fighting on the tops of skyscrapers in some unknown metropolitan area, while coming to a climax in fighting a horrible mutant of a man to get on a train.
First stage of Ninja Gaiden 2
And that is not all--the lights even flicker. By a rotation of palette index numbers for the pixels in the tiles, the colour linked to that pixel would flicker as if the lights were switched on or off. This in turn increased the illusion of a bustling city and is a technique used by some to a point of genius.
The aforementioned train was your setup for the next level where you were treated to a real technical marvel for the time: parallax scrolling. By using the line interrupt feature of the MMC3, which was one of the mappers provided by Nintendo, the people at Tecmo added some nifty parallax scrolling to the game. While you jump from train cart to train cart with a mountain backdrop everything scrolls at different speeds thus giving the illusion of depth.
The way this worked was that after each scanline a counter would be increased in number by one. If this counter matched the preset number it would trigger an interrupt for the CPU to act upon. The MMC3 also allowed the programmer to set a new value and 'reload' this by command. This would cause the updated value to be loaded at the end of a scanline. It is for this reason that the stage was able to have different scroll speeds at different scanlines thus creating the illusion of depth. It was actually meant for split-screen games, but creative developers were able to use it for other purposes.
Second stage of Ninja Gaiden 2 With Paralax Scrolling
The earlier mentioned colour cycling technique was often used to create animation in the background. Each colour used in a tile stores as a number in a palette. By rotating these numbers it was possible to give the illusion of movement. This was often used for waterfalls, conveyer belts and rain. The technique was a lot cheaper for memory usage than storing different tile patterns for each frame of animation and could still yield stunning effects. A good example of this is Megaman 2.
In Megaman 2 the technique is utilized on almost every level: the conveyor belts of Metalman to the waterfalls in the background of Bubbleman and also the ice blocks of Flashman all where done with the cycling of colours. In fact, even the small bubbles you see every so often on the top of Bubbleman's stage are just pixels with the same index numbers as the ones of the waterfall, this created the illusion as where one in a giant aquarium tank with air blown into the water to prevent it from growing stale.
Megaman 2:Flashman stage with colour cycling used for the ice blocks
A compilation of Megaman 2 Cycling effects. Everything from the waterfalls, splashes in the water, Lava and bubbles are colour cycled.
This same effect was usually used to create the many flashing objects in Megaman and other games of the time; it's a very handy technique for developers allowing for animation otherwise not possible with the memory limitations given.
Colour knowledge and image build-up on old TV sets was often used in the advantage of creating illusions of more colours or animations. For example on old CRT televisions neighboring pixels and scanlines would often blend with each other. With these limitations a good programmer would be able to create the illusion of more colours or even some hints of “translucency” via a well-chosen dithering. This in turn also meant that one had to use clashing or very clear colour differences to create contrast for things that had to stand out. Things like the player or blocks to stand on were often designed in such a way that they would be clear to see even on the fuzzy screens of the day.
Not to be confused with colour bleeding, this detrimental effect could be seen in some ZX-Spectrum and MSX games where a pixel line of colours kept going because of hardware limitations. So for the next examples keep in mind that these games were designed to be shown on older TV sets and not on the 1080p monitors and sets we play them on now.
As a first example I would like to show the second level of the game Cyber Shinobi for the SEGA Master system. Although the gameplay of this game is hit or miss, with some finding it absolutely terrible, it was a personal favourite of mine while growing up. Especially the first stage which had these beautiful vistas drawn with the use of only a few tints of green and yellow.
In the distance you can see the other side of the harbour, possibly Hong Kong, in which you are fighting. The shimmering water represented by a few well-chosen dark green, light green, yellow and lighter yellow pixels, as where they reflecting the buildings in the distance. All the while most of the space actually remained black. The buildings themselves were brighter, more yellow, some red and light green, as if clearer to see but further in the distance than the water in which they were reflected.
The second stage of Cyber Shinobi. Although here pixel perfect, on a CRT TV of old the colours would be blended.
Simple as it may look here, it actually is not that easy to pull off without knowledge of colours and how they would refract in the water at night.
Another example of great background and level artistry is the sheer magic Konami was pulling out of the MSX 1. Like the ZX-Spectrum it was prone to colour bleeding and on top of that there was no hardware scrolling whatsoever, but games like the NEMESIS/Gradius series gave us beauties like these in full motion and often animated:
Organic Stage of Nemesis 2
Nemesis 3 Botanical stage
It wasn't just here that Konami was able to work magic, Castlevania 3 was able to use its own mappers. As mentioned earlier, Nintendo only allowed the use of their own branded mapper chips and lacked the ability to add sound channels. Although the MMC5 lacked some of the features present in Konami's own VRC6, it still was a sight to behold when playing it for the first time. The graphics only really started to shine in the later levels which even showed fog effects animating per line creating a creepy atmosphere. Or the rotating gears in a clock tower.
Western version of Castelvania 3's Clocktower.
Now with the brilliant pixel art of Konami I would like to end this slight lamentation of this art form and with some hope that I got some of the readers interested, if not hooked, to play these games for themselves. In any matter it was great writing about this subject as it is a section of pixel art often under-represented in an area of gaming where sprite art was stealing most of the limelight.
Just before I go I wish to share some links regarding the demo scene of the C64 and what great pixel art they have created over the years and a link of an artist, Mark Ferrari, who used to make backgrounds for games and now has some great colour cycled works of art posted on his web page. Thank you for reading!
http://c64pixels.com/main.php
http://markferrari.com/
