Sprite Kit provides a graphics rendering and animation infrastructure that one can use to animate arbitrary textured images, or sprites. Sprite Kit uses a traditional rendering loop where the contents of each frame are processed before the frame is rendered. A game determines the contents of the scene and how those contents change in each frame. Sprite Kit does the work to render frames of animation efficiently using the graphics hardware. Sprite Kit is optimized so that the positions of sprites can be changed arbitrarily in each frame of animation.