Virtual autumn coloring system based on biological and fractal model

The authors simulate the time evolution of autumn coloring of both maple leaves and entire trees, and propose both biological and fractal models of this process. We calculate the amount of sunlight received on the leaves and propose the "autumn-coloring-logical-time" that is the temporal indicator of autumn coloring, then we use experimental biological data to calibrate the model parameters. Using the leaf fractalities, we adopt a chaos game algorithm or random iteration algorithm to render natural autumn colorings.