Geometry Modeling for Cotton Leaf Based on NURBS

Digitalization of agriculture bring controllable industrial production and computer-aided design ideas into agriculture, NURBS curves and surfaces is described freedom of widely popular technology, CAD systems are widely used. Method can be easily applied to generate curves, surfaces with NURBS. In this paper, we have developed model of cotton organs using NURBS surface, present a introduction of Topological Structures on virtual plant from our personal perspective and simulated a 3-D growing of cotton with OpenGL and VC++ 6.0.briefly introduce method of simulating cotton organ based on NURBS and from our personal perspective present a introduction of Topological Structures on virtual plant. Based on VC++6.0 and OpenGL, methods of establishing models of main cotton organ using techniques of computer graphics are presented and realistic results have been achieved. Burls of stem and fruit branches are simulated by octahedronlike prism. Other organs are built based on NURBS. These organs are: bell、caulis leaf、fruit branch leaf、Petal、bract. Using NURBS we don’ t need to obtain an abundance of accurate data and bother with regression equation by contrast with three-dimensional digital. Topological Structures of cotton is represented by C++ class: stem class and fruit branch class. Key-Words: NURBS, OpenGL, C++, Cotton, Topological structures