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Color Cycling

Color cycling is a method used to add simple animations to images without using individual frames.
Instead neighboring palette entries were swapped around, making it possible to change complete pixel groups.

The effect and its limitations can be best compared to the way that old advertisement billboards, made out of fluorescent tubes, worked.

DeluxePaint_Waterfall

DeluxePaint_Yacht

Diga
  • Diga
  • 1991
  • Lowres (NTSC)
  • 32 colors
  • ColorCycling

AH_Lemur

Boing

The Amiga Boing Ball demo was created during a night at the 1984 CES by Dale Luck and R. J. Mical and it is told that show visitors completely blown away by this.

The demo itself was a very clever demonstration of how it's custom chips could be used to fake an effect rather than to create it with pure processing power.
In reality nothing on screen is redrawn during the demo.

The ball itself is rendered at the beginning of the demo and then 'animated' with the color cycling method.
The motion of the ball is done by moving the scroll positions of the different bitplanes. It uses 3 bitplanes, while the grid uses another bitplane and the shadow uses the last bitplane.
The clever selection of color registers makes it possible to have a shadow that works correctly with the grid while not interfering with the ball. This is also the reason why this image needs 32 colors and why the color palette contains mostly duplicates.

All this means that the demo does full hardware scrolling, costing next to no cpu processing power.

DefenderOfTheCrown2

From Defender of the Crown 2

DefenderOfTheCrownCDTV

From Defender of the Crown CDTV

DefenderOfTheCrown

From Defender of the Crown

DefenderOfTheCrown2
DefenderOfTheCrownCDTV
DefenderOfTheCrown

DefenderOfTheCrown2_BritainMap

From Defender of the Crown 2

The hand painted map from Defender of the Crown was replaced by a picture that was grabbed from video and touched up.

This was a technique that Jim used more often in his later work to speed up his workflow, because pixeling everything by hand took a lot of time, which was rarely available when developing a game.

DefenderOfTheCrown_BritainMap

From Defender of the Crown

DefenderOfTheCrown2_BritainMap
DefenderOfTheCrown_BritainMap

DefenderOfTheCrown2_CastleNorman_day

From Defender of the Crown 2

DefenderOfTheCrown2_CastleNorman_night

From Defender of the Crown 2

DefenderOfTheCrown_CastleNorman_day

From Defender of the Crown with a day time palette.

The castle pictures from Defender of the Crown used the same picture but with different color palettes for the day and night time versions.

DefenderOfTheCrown_CastleNorman_night

From Defender of the Crown with a night time palette

DefenderOfTheCrown2_CastleNorman_day
DefenderOfTheCrown2_CastleNorman_night
DefenderOfTheCrown_CastleNorman_day
DefenderOfTheCrown_CastleNorman_night

DefenderOfTheCrown2_CastleNormanHall

From Defender of the Crown 2

DefenderOfTheCrown_CastleNormanHall

From Defender of the Crown

DefenderOfTheCrown2_CastleNormanHall
DefenderOfTheCrown_CastleNormanHall

DefenderOfTheCrown2_Normans

From Defender of the Crown 2

DefenderOfTheCrown_Normans

From Defender of the Crown

DefenderOfTheCrown2_Normans
DefenderOfTheCrown_Normans

DefenderOfTheCrown2_RobinHood

From Defender of the Crown 2.

DefenderOfTheCrown_RobinHood

From Defender of the Crown.

This image was not drawn by Jim Sachs and he was not happy with it. He therefore created a completely new version for Defender of the Crown 2.

DefenderOfTheCrown2_RobinHood
DefenderOfTheCrown_RobinHood

JimSachs_20000LeaguesUnderTheSea_Beach

JimSachs_20000LeaguesUnderTheSea_Shipwreck

JimSachs_20000LeaguesUnderTheSea_Shipwreck_var
JimSachs_20000LeaguesUnderTheSea_Shipwreck
JimSachs_20000LeaguesUnderTheSea_Shipwreck_var

JimSachs_20000LeaguesUnderTheSea_Sunset

This image belonged to a sequence where the Nautilus can be seen sinking slowly in the sunset. Jim captured this sequence from a VHS recording that he had made from the game demo during development and posted it on his personal YouTube channel.

JimSachs_Aquarium
  • Jim Sachs
  • Lowres (NTSC)
  • 32 colors
  • ColorCycling

JimSachs_Centurion_RomanEmpire

JimSachs_PortsOfCall

JimSachs_PortsOfCall_var
JimSachs_PortsOfCall
JimSachs_PortsOfCall_var

Jim re-used the title picture for Ports of Call in his abandoned [link=/game/20000LeaguesUnderTheSea.html]20.000 Leagues under the Sea[/link] project.

The german magazine Amiga Magazin did an article on Jim Sachs in their August 1989 issue. They previewed a screen from the project, while it was still in development, and you can clearly see the same sky, mountains and buildings.

JimSachs_PortsOfCall_Storm

JimSachs_Sonix

ljl_ArtificialHeart

ljl_Champagne

ljl_JumboDog

ljl_JumboDog_MoreDogs
ljl_JumboDog
ljl_JumboDog_MoreDogs

ljl_Skier

SAK_NightFlight

SAK_SnowScape