Modeling fractures and cracks on tree branches

Abstract

Wood is a complex biological material. Due to the anisotropy of wood, the difference in the structure and physical-mechanical properties of different tree species, and the irregularity and complexity of the internal structure of tree branches, it is challenging to model wood fractures caused by natural disasters and man-made damage. In this paper, we propose a user-controllable procedural modeling algorithm simulating the fractures based on the theory of wood science and wood fracture mechanics. It can also simulate cracks caused by wood shrinkage. The roughness of the corresponding area on the fracture surface is adjusted by setting the parameters of different material properties of pith, heartwood, sapwood, and bark; when the branches are broken, the fracture surface of the wood area under tension is treated as uneven and full of spines, and the pressure part is treated as a more regular section; the wood composed of different types of plant cells is represented by a group of particles. Various realistic cracks on wood fracture surface can be simulated by setting different strength and shrinkage rate in axial, radial and tangential direction. We illustrate our approach with various models from several tree species. Experimental results indicate that our approach can be used to model fractures and cracks on tree branches efficiently and realistically.