基于NURBS曲面的小麦叶片三维可视化研究与实现

作物三维可视化将为作物生长动态预测、栽培管理调控、作物株型设计等提供形象逼真的可视化工具,从而有力促进虚拟农业和信息农业的发展。针对小麦形态结构复杂、叶片三维可视化不易表达的问题,基于田间实测数据和NURBS曲面建模实现了小麦叶片的三维重建。首先,通过田间实验定期观测小麦形态数据(叶长、叶宽、茎叶夹角、叶片弯曲度、茎秆直径等),建立小麦叶片主脉控制点构造算法,将小麦形态数据转换为主脉控制点坐标;其次,确定所有控制点坐标和节点矢量,构建小麦叶片和叶鞘NURBS曲面;最后,借助Open GL图形库可实现小麦不同生育期的模拟模型,并实现了小麦叶片的扭曲形变。结果表明该方法选取的小麦形态数据具有代表性,重建的小麦叶片模型逼真度较高,接近实测模型,易于实现小麦生长过程的动态模拟。

Research and Realization of Wheat Leaf Three-dimensional Visualization Based on NURBS Surface

Crop three-dimensional visualization will provide image lifelike visual tools for crop growth dynamic prediction, cultivation management control and crop plant type design, so as to effectively promote the development of the virtual agriculture and information agriculture. Since morphological structure of wheat is complex and three-dimensional visualization of the leaf is not easy to express, wheat leaf three-dimensional visualization were realized based on measured data and NURBS surface modeling. Firstly, wheat morphological data (leaf length, leaf width, stem and leaf angle, leaf bending angle, stem diameter, etc.) were collected from the field experiment, and then wheat leaf main vein control point construction algorithm were established, and the coordinates of the leaf main vein control point were calculated. Secondly, all control point coordinates and node vectors were calculated, the wheat leaf and leaf sheath surface model were built. Finally, the wheat simulation model of different growth period can be built with OpenGL graphics library, and the wheat leaf twisting deformation was implemented. The results showed that the selected wheat morphological data were representative, the reconstructed wheat leaf model were close to the real model, and it was easy to realize the dynamic simulation of wheat growth process.