Research On Visualization Algorithm Of Wood Fracture Simulation

Wood fracture simulation is an important part of natural landscape simulation.Because wood is a complex biological organism,it is difficult to simulate the fracture of wood and branches by traditional methods.In addition,the diversity of wood structure and wood physical and mechanical properties of different tree species,irregularities and complexity of internal structure of branches increase this complexity.The manual modeling by the 3D modeler always takes a long time,and this method is inconvenient to generate a fracture animation;the broken tree model collected by the 3D scanning instrument is prone to many voids due to the uneven and staggered wood thorns at the wood fracture;The use of random noise to generate the fracture surface of wood results in a lack of realism due to the excessively simplified wood characteristics.In this paper,a wood fracture simulation algorithm based on wood science and wood internal structure reconstruction is proposed.By studying the characteristics of the branch fracture surface,reconstructing the internal structure of the wood based on the outer contour of the branch,and analyzing the differences in the branch fracture effects of different tree species,etc.The key factors of the breaking effect of the branches are integrated into the procedural modeling of the wood fracture surface.The main contents and innovations are as follows:(1)Parametric modeling of tree branch fracture surface: An algorithm that uses computer graphics technology to interactively generate realistic wood fracture surfaces in real time is provided.This algorithm provides multiple parameters.Users can set the relevant parameters according to needs to refine breaking effect richly.Users can obtain the obvious effect of layering by setting the angle,orientation and height of a certain section on the fracture surface.A plurality of Perlin noise and white noise adjusted by parameters is added on the axial height of the vertices on the cross-section to obtain richer details and stronger irregularities.This article also explores the relationship between the difference in physical and mechanical properties of different tree species and the difference in fracture effect by analyzing the samples of real branches collected from woodland.(2)Modeling of tree branch fracture surface based on external contour: An algorithm for reconstructing wood annual rings and wood fiber bundles inside the 3D model of the tree branch is proposed,and a reasonable internal structure of the tree branch is generated: a hierarchy consisting of multiple ring-like annual rings structure,each annual ring is divided into a series of connected fan rings.Based on this reconstruction result,an algorithm for mapping the wood fracture surface generated by parametric modeling to an irregular 3D tree branch model is proposed,and a tree branch fracture surface that conforms to the wood structure,is realistic,and fits the 3D model is generated.(3)Wood crack simulation: An algorithm to simulate radial cracks on wood rays is proposed,as well as an algorithm that simulates tangential cracks between early wood and the late wood on another annual ring.The algorithm proposed in this paper captures the basic characteristics of the wood fracture effect,and the generated realistic broken tree model can be used for animated movie special effects,real-time games,real scene simulation,wood knowledge assisted education,etc.