The ray reflection, refraction, diffusion, and transparency are important functions for visualizing 3D objects. Every ray intersection with object boundaries and its normal direction on the intersecting point are used to simulate the optical interference of rays with objects. It is theoretically impossible, however, to construct smoothly interpolated continuous boundaries from a discrete array of sampled values, such as a set of volume elements. Although many volume visualization techniques have been proposed, it is still difficult to ensure appropriate surface topology by a simple algorithm. In the present paper, two new isosurface constructors named MMC (Modified Marching Cubes) and DC (Deformed Cubes) are investigated. MMC is a modification of Marching Cubes algorithm, which is well known as a high resolution isosurface constructor. MMC algorithm produces topologically correct triangulated isosurfaces that are guaranteed to be orientable and closed. DC algorithm is much simpler than MMC, and the produced triangulated isosurfaces are also topologically adequate, and as accurate as MMC. Experimental results and comparisons of the interpolated triangulated isosurfaces in terms of the shape precision between MMC and DC are also presented.