Simulation of Autumn Leaves

The deformation of a leaf is the aggregation of the deformation of all the cells on the leaf. Mesophyll cells and vascular bundle cells have distinctly different degree of rigidity for shrinkage. In order to simulate the deformation of an autumn leaf realistically we need the realistic venation distribution of the leaf. We modify Runions’s technique [Runions et al. 2005] by increasing the growing speed of the strongest vein or the primary vein on the top growing point. Then, according to the venation, a double layered model (DLM), a physically-based mechanism, is proposed to simulate the deformation of autumn leaves. In DLM, the upper layer stands for the cells in mesophyll which have remarkable shrinking ratio, meanwhile the lower layer stands for the cells in venation which are more rigid to resist the shrinking force, as shown in Fig. 2. The two layers are also inter-connected to hold the mechanical stability. By setting up the mass-spring system in two interconnecting layers, different kinetic manners of mesophyll and veins can be simulated respectively. Meanwhile the double layers affect each other and determine together the deformed shape of leaves.