3维植物叶片精确建模和绘制技术研究

Research on Techniques for Accurate Modeling and Rendering 3D Plant Leaf

准确、灵活的叶片模型对植物建模具有重要的意义,但目前大部分植物叶片曲面模型没有提供足够的准确性和细节描述。为了给生成准确、细致的叶片几何模型提供灵活的方法,即首先利用B样条曲线来描述叶片的边缘轮廓和主脉;然后用Delaunay三角化方法对叶片曲面进行网格化;最后通过改进Loop细分规则的自适应细分方法来优化叶片曲面,从而为植物叶片提供了一种灵活的3维几何造型描述方法。由于B样条曲线能够很好地描述大部分植物叶子的轮廓,Delaunay三角化方法的使用又解决了包含多个裂片的叶片曲面的网格化问题,而自适应曲面细分方法则不仅使得生成的空间曲面具有更高的光滑度,同时可使得生成的叶片曲面能够进行卷曲变形。实验结果充分表明,该方法是有效的。

A variety of models for plant leaf morphogenesis have been reported, but none of them can be generated with great accuracy or level of detail. In this paper B-spline curve is used to describe the silhouette and midvein of plant leaf, and the leaf blade surface is meshed with Delaunay triangulation. Then an adaptive refinement scheme is introduced to smooth the triangular mesh. This may provide a common method for describing the morphology of plant leaf blade. B-spline curves which pass through the control points gives an intuitive mechanism to model the silhouette of a wide variety of plant leaf, and the usage of Delaunay triangulation solves the difficulty of meshing complex leaf blade such as lobbed leaf. In addition, our adaptive subdivision scheme can generate relative smooth leaf surface, and the curled effects can be obtained basing on the subdivided surface. The experimental results verify the validity of the proposed method.