Wrap-around operation for Multi-resolution CAD model

In the design of a very complex product, the multi-resolution modeling technique plays an important role for the real time operation of the model on computers. There are many previous works to simplify or compress the geometric data to obtain a multi-resolution model from the original shape. But, most of them focused on the generation of multi-resolution model for facetbased models, not for B-rep models. The facet model is good enough for rendering purpose, but is not the basis model for many commercial CAD systems. A new multi-resolution algorithm for the B-rep model is needed to improve the interactivity in dealing with a large assembly model generated by CAD systems. We propose a new modeling operation, called wrap-around, to simplify a B-rep model. With this operation, a part model and an assembly can be simplified efficiently to yield multi-resolution models. Also, applying the reverse wrap-around operation can recover the original un-simplified model. In this paper, the structures and the processes to realize this operation are discussed in details, and some examples are also demonstrated.