Study On Model-Based Visualization Of Rice Roots

Virtual roots are to simulate roots morphological architecture and growth processes in three-dimensional space visually on computer, which is an important part of virtual crop, and has important realistic significance and wide application prospects in agronomy, ecology and virtual teaching. Based on the multidisciplinary theories and technologies of crop science, applied mathematics, computer graphics, virtual reality and relevant knowledge of home and abroad, a dynamic model of root morphology in rice was developed. Then, the key techniques for rice root geometry model, realistic rendering, collision detection and reponse were developed by the computer visualization technology. Finally, based on object-oriented program design and software component technology, a model-based visualization of rice roots growth system was established, which realized the visualization of rice roots on the computer. This study would lay the foundation for visualization of rice plant and population growth.System analysis principle and geometric modeling technology were applied to rice roots morphological modeling, an architectural parameter-based geometrical model for rice roots were developed by analyzing the change patterns of root-tip growth with development processes. By integrating the topological structure of rice root, a three-dimensional visualization model of rice root was established using GDD as driving factor, including the sub-models of the initial emergence time and location, initial extension angle, elongation rate and spatial distribution of adventitious root in rice. The main controlling parameters of model were the total number of leaves of the main stem, total number of stretched-out nodes of the main stem, the initial coordinates, the initial growth vector, the number of root, the length of root, the maximum of cross-section radius. The model could describe the dynamic changes of rice root growth process, and the parameters of model had definite biological meanings. The established model could be easily integrated with other rice morphological model, and thus lay a foundation for rice roots visual growth.Based on the morphological modeling of rice root, the 3D graphics of root in rice was realized by selecting element figures of point, line and cylinder. Further by using of realistic graphics display technology of computer graphics, such as illumination treatment, color rendering and texture mapping, visualization of rice roots were realized. Preliminary studies on the rice root of collision detection and response mechanism was conducted. Finally, data structure storage and protract mechanism of rice roots dynamic growth were proposed through determination of the main control parameters of model. This method could serve as the key technology for visualization rice roots growth.Driven by weather, variety, management databases and integrating rice root geometry model and visualization model, a model-based visualization of rice roots growth system was established by using Visual C++ programming language and the platform of OpenGL, adopting Access 2000 database structure. The implemented system could be used for visualization of morphological architecture of rice root under various genotypes and water regimes and nitrogen levels on single root and roots levels. Results showed that the system would be useful for improving the overall level of visual and digital rice growth system and further developing virtual farming technology.