Handling small features in isosurface generation using Marching Cubes

Abstract

The Marching Cubes (MC) algorithm is a well-known surface-rendering algorithm for volume visualization. However, it has problems in handling small features having a size of one voxel. There are two possible kinds of small features, denoted by type A and type B. The type A feature occurs when at least one cube face has an intersection point in each of its four edges. The type A feature also leads to the “hole problem” due to the ambiguity in the topology. The type B feature occurs when a cube has at least one edge with values of both of its ends being above or below the threshold. We show that if type B features are to be represented with the same accuracy as the type A ones, it would be very computation-intensive and unacceptable for interactive applications. For such applications, there is no need to represent type A features with high accuracy by using complicated methods suggested in the past literature. We present a new approach to handle the type A features which is much simpler than the previous approaches and is also more efficient. This new method is consistent in the sense that all types of small features having the same level of detail are represented with equal accuracy.