在虚拟现实等技术领域中，都涉及到由现实世界中的实际景物建立对应的计算机描述的虚拟景物的问题，为此提出了利用计算机视觉与CAD几何建模技术相结合的三维珠体建模途径，首先通过编码光栅方法获取三维物体的深度图象，并采用数学形态学的方法加以分割，然后利用代数曲面拟合手段对分割后的三维曲面片进行重建，并使用CAD几何建模工具由重建的曲面片构成物体的几何模型，该文给出了初步的实验结果，证明所提出的技术途径基本可行。

In areas such as virtual reality,it is often needed to establish virtual scene in computer from actual scene in real world.In this paper,a technical approach for realizing geometric modeling of 3D object is proposed,which combines computer vision and CAD geometric modeling.The range images of 3D objects are obtained by using the encoded light stripe patterns,then are segmented by our range image segmentation method based on the basic operations of methematical morphology. The meaningful regions obtained by range image segmentation correspond to the surface patches of 3D object.The 3D surface patches are then reconstructed by the algebraic surface fitting method;the surface parameters are estimated by solving generalized eigenvector problem. The geometric model of 3D object is constructed from reconstructed surface patches by using CAD geometric modeling tool GEOMOD.The primary experimental results of two mechanical parts are presented,which prove the proposed approach is feasible.