The whole process of mesh generation is presented in detail. Advancing front technique (AFT) is proposed for 3D tetrahedral mesh generation [1]. AFT starts from initial front. Initial front is a boundary surface conformal triangulation. On each step a new tetrahedron is constructed and the front is updated. At this point local mesh size could be selected automatically in order to create quasi-u...

Within a shipyard, many designers each having their own design objective cooperate in a complex design situation where a variety of software tools run on different hardware platforms. The exchange of design data models among these heterogeneous CAD systems is a difficult task because the systems involved have different data structures optimized for their own functions. CAD geometric models are ...

With today’s Virtual Reality (VR) systems, it is difficult to directly and precisely create and modify objects in a VR environment. This chapter presents an approach for solid modelling in a VR environment. Solid modelling in the VR environment is performed precisely in an intuitive manner through constraint-based manipulations. A hierarchically structured and constraint-based data model is dev...

This paper extends a recently proposed robust computational framework for constructing the boundary representation (brep) of the volume swept by a given smooth solid moving along a one parameter family h of rigid motions. Our extension allows the input solid to have sharp features, i.e., to be of class G0 wherein, the unit outward normal to the solid may be discontinuous. In the earlier framewo...

Until recently terrain models were developed in a GIS, and built-up structures were modelled using a CAD system. Extending the current “2.5D” TIN model by incorporating CAD functions is a necessary development, while preserving topological integrity. A solid-modelling CAD system may be excessive for our “extended 2D” mapping needs, but the CAD “boundary representation” (brep) design, based on m...

In this work, we propose a detailed computational framework for modelling the envelope of the swept volume, that is the boundary of the volume obtained by sweeping an input solid along a trajectory of rigid motions. Our framework is adapted to the well-established industry-standard brep format to enable its implementation in modern CAD systems. This is achieved via a “local analysis”, which cov...

We present a novel integrated approach to reverse engineering point clouds by producing fully editable feature-based Boundary Representation (B-rep) models. We use point cloud morphology analysis techniques to extract features from a 3D point cloud. We then reconstruct the boundary contours of features using a fast and efficient fitting approach employing a sequence of piecewise rational Bezier...

We present a system for fast and accurate display of CSG (constructive solid geometry) models. Such models have as primitives, polyhedra and solids whose boundaries can be represented using rational spline surfaces. As a part of pre-processing, we compute the Brep (boundary representation) from the CSG tree and represent the resulting solid using trimmed spline surfaces. No assumptions are made...