World Heroes 2
World Heroes 2 is the only game that applies exactly the method described in one of SNK's patents for animating a rotating sphere or cylinder.
It is used for the short earth animation just before the title screen: a flat texture of the earth's surface is mapped in several horizontal sprite blocks which are positioned and scaled to approximately fit in a circle shape. Each sprite's horizontal shrinking is then adjusted and tiles are remapped when they "go out of the right edge". The resulting different scrolling speeds and tile sizes create the sphere illusion.
Another static sprite block is layed on top as a stencil to mask out the corners of the sprite strips.
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15 horizontal sprite blocks of 16 sprites each. The vertical shrinking coefficients are fixed.
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Mask layer, the outside of the circle is black, the center is transparent.
