Symmetry and Fourier Descriptor: A Hybrid Feature For NURBS based B-Rep Models Retrieval

Before we start to tessellate the trimmed NURBS surface, we give an introduction of the tessellation of an untrimmed NURBS surface, which is based on the methodology of

Understanding shape of point sets, either they are stratified or not, is crucial in the design of b-rep geometric data struc- tures and their shape operators (e.g. Euler

As Figure 2 shows, attempts to refine mesh approximations to curved surfaces will generate new vertices that lie, not on the exact surface where we would like, but on the

The first issue we must address is to define a measure of symmetry for a 3D model with respect to an axis of k-fold rotation or a plane of reflection. To this end, we describe a

First, we consider the case of a single instance set: This means, we are given symmet- ric subgraphs with sets of features F 1 , …, F m , and rigid transformations T i,j that

Since each SIFT descriptor is a low-level feature, the entire set of descriptors extracted from the image collection is divided into a fixed number of clusters with each cluster

In contrast to shape retrieval approaches based on global descriptors where object similarity can be determined in a straight forward way by computing the distance between

As discussed in Section 3, global symmetry detection is a special case of partial symmetry detection. We now dis- cuss five main approaches for partial symmetry detec- tion: