基于形态特征参数的稻穗几何建模及可视化研究

Architectural Parameter-Based Geometric Modeling and Visualization of Rice Panicle

【目的】建立基于形态特征参数的稻穗几何模型,实现稻穗的可视化。【方法】通过对稻穗形态建成过程中关键特征的观测分析,利用三维几何建模技术,构建基于形态特征参数的稻穗几何模型,包括穗曲线、穗轴、次枝梗和小穗几何模型;用Bezier曲线来拟合穗曲线,将二维空间的穗曲线映射到三维空间,构建穗轴几何模型;用一段穗轴及圆柱体模拟一次枝梗和二次枝梗;并分别用椭球体及圆柱体模拟小穗的谷粒及小枝梗,最后基于稻穗的拓扑结构,构建稻穗几何模型。模型参数主要有穗长、穗倾角、一次枝梗长、一次枝梗数目、二次枝梗长、二次枝梗数目、谷粒大小等。【结果】在稻穗几何模型基础上,基于OpenGL图形平台,实现了稻穗生长过程的三维可视化,较好地描述了稻穗形态建成过程。【结论】稻穗的可视化为建立可视化水稻生长系统奠定了基础,同时对其它作物的可视化表达也有很好的借鉴意义。

【Objective】 The aim of the study was to develop an architectural parameter-based geometrical model and realize the visualization of panicle in rice. 【Method】 Based on measuring and analysing morphological structure of rice panicle, an architectural parameter-based geometrical model for rice panicle was developed by using 3D geometric modeling technology. The model included 4 submodels： panicle axis curve, panicle axis geometry, primary and secondary branch geometry, and spikelet geometry submodels. Bezier curves were used to simulate dynamics of the panicle axis curve, panicle axis geometry submodel was developed by mapping panicle axis curve to 3D, primary and secondary branch geometry submodel was developed with a part of panicle axis and a cylinder, spikelet geometry submodel was developed by a ellipsoid and a cylinder. Based on topographic structure of rice panicle, the rice panicle geometrical model was developed. The main parameters of the model were the length of panicle, the angle of panicle-neck, the length and number of primary and secondary branches, the grain size and so on. 【Result】 Based on the geometrical model for rice panicle and the platform of OpenGL, the dynamic growth processes of three-dimensional morphological structure of rice panicle was realized on the computer. 【Conclusion】 Rice panicle visualization could lay a foundation for development of visual growth system in rice and be used for reference to the visualization of other crops.