A 3D surface model of human anatomy is widely used in medical imaging software to increase visualization of volumetric data in 3D. In the first part of the paper, we present a process for fast 3D surface reconstruction with high quality from large volumetric data. The subsampling technique is used to support large volumetric data. After constructing the contours, we apply the smoothing technique to smooth out the polygon mesh. Specifically, in this study, we focus on the subsampling and smoothing parameters that affect the quality of the 3D surface model and the efficiency of the computation time. In addition to 3D surface reconstruction, 3D surface clipping is also useful for visualization because it allows one to see detail structures inside the surface model. In the second part of the paper, we propose another process to perform 3D surface clipping on volumetric data. Clipping along an arbitrary plane requires the position and orientation of that clipping plane. Since, with clipping only, the corresponding clipped surface produces empty holes, a texture mapping technique is used to cover the holes by placing the cut image data of that clipping plane on top of the clipped surface. Our proposed processes in this paper are based on the Visualization Toolkit (VTK) library.