摘要
作物器官几何建模是虚拟作物研究的关键技术之一。通过对小麦穗形态结构的观测分析,提出基于形态特征参数的麦穗几何模型及可视化实现方法。在已有麦穗形态模拟模型的基础上,结合麦穗拓扑结构,构建麦穗形态结构几何模型,包括穗轴、小穗(外麸、麦芒、花药等)、麦穗穗形等子模型。其中,穗轴节片使用底面为椭圆的圆柱体进行模拟,节片交错叠加构成穗轴。基于外麸曲面半径变化曲线,以三角面片构造近似半椭球体来模拟外麸;基于麦芒曲线,以三角面片重构横截面近似为等边三角形的麦芒;用非统一有理B样条曲面模拟开花期小花顶端的花药;采用分层模型控制麦穗穗形。然后根据麦穗拓扑结构组合以上各器官,即可构建出麦穗几何模型。进一步结合颜色渲染、纹理映射、光照渲染等真实感显示技术,基于.Net平台,借助CSOpenGL,实现麦穗生长动态的可视化。结果表明,重构出的麦穗具有一定的真实感,能够用于不同品种、不同处理条件下麦穗生长动态的可视化表达。研究结果将有助于实现小麦植株生长动态的数字化、可视化。
Crop organ morphological model is one of the key technologies of virual crop.By observing and analyzing the morphological and topological structures of wheat spike,the morphological parameter-based 3D geometric model and visualization method were developed.Based on the existing morphological model of spike in wheat,the 3D morphological geometric model of wheat spike was constructed by integrating the topological structure of spike,including the submodels of ear axis,spikelet（including outer bran,awn and anther） and spike shape.The ear axis was constructed by connected proglottids which were represented by slant cylinder.Based on the surface vertical curve,the outer bran was simulated by approximate semiellipsoid with triangular faces.The awn,with transversal surface as nearly equilateral triangular,was constructed by triangular faces based on the curve of awn.The anther on the top of floret in flowering stage was simulated with NURBS surface.In addition,the spike shape was controlled by using hierarchical model.Then according to the topological structure,the above organ models were organized together to rebuild the whole 3D geometric model of wheat spike.By further integrating the rendering models of color,texture and light,the visualization of growth dynamic of wheat spike was realized based on the platform of Microsoft.Net and CSOpenGL graphic library.The reconstructed geometric model with three dimensions can simulate visualization of growth dynamic of wheat spike under different varieties and treatments.The result will be helpful to realizing the realistic simulation of wheat plant,and the digitalization and visualization of growth dynamic of wheat.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2011年第3期179-184,I0003,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(30800136,30971697)
江苏省科技支撑项目(BE2009342)资助
关键词
可视化
模型
作物
穗形
小麦
visualization
model
crops
spike shape
wheat
