A physics-based approach to motion capture data processing for virtual plant modeling and simulation

Dynamic virtual plant simulation is an attractive research issue in both botany and computer graphics.Data-driven method is an efficient way for motion analysis and animation synthesis.As a widely used tool,motion capture has been used in plant motion data acquisition and analysis.The most prominent and important problem in motion capture for plants is primary data processing such as missing markers reconstruction.This paper presents a novel physics-based approach to motion capture data processing of plants.Firstly,a physics-based mechanics model is found by Lagrangian mechanics for a motion captured plant organ such as a leaf,and then its dynamic mechanical properties are analyzed and relevant model parameters are evaluated.Further,by using the physical model with evaluated parameters,we can calculate the next positions of a maker to reconstruct the missing makers in motion capture sequence.We take an example of a maize leaf and pachira leaf to examine the proposed approach,and the results show that the physics-based method is feasible and effective for plant motion data processing.

An interactive design method for realistic fruit rot modeling and simulation

This paper presents a general 3D method to simulate a rotting process in fruits using a visual model for the digital design of the fruits.The global rot parameter and rot resistance parameter are used to control a dynamic simulation of a rotting process.The rot resistance parameters of every point of a 3D fruit model are generated by an interactive designing method that is similar to the traditional sketch drawing tools.We construct a texture of a rot region on a fruit surface by resistance parameters.The degree of rot that is used to control both shape and appearance of rotten fruit surface can be computed by tuning the resistance parameters and global rot parameters.We derive an exponential function to calculate the depression displacement of geometric shape caused by the rot.In order to render a wrinkle on the rot region,we use a normal noise map to modify a normal vector of fruit model and use an isotropic ward BRDF model to represent an appearance of fruit in which the time-varying diffuse reflectance is derived from the real photos.We utilize a linear function to control the dynamic simulation processes including shape deformation and aging appearance.We have evaluated our method by simulating the rotten apple and moldy orange.The results have shown that our method provides a dynamic,real-time and realistic simulation,and it is flexible,fast and of a general character for digital fruit design as a visualization model.