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.