This paper presents a scan curve algorithm for evaluating the face area of solids in constructive solid geometry (CSG) representation. Compared to previous methods, the algorithm is more accurate and computationally faster. The applicable domain is limited to solids bounded by three classes of surfaces: all quadric surfaces, cylindrical surfaces, and surfaces of revolution which are algebraic s...

While the framework of Isogeometric Analysis (IGA) has opened new perspectives for the improved interaction between design and analysis, it has also led to new challenging problems which are related to the representation of the geometry. In particular, while models in geometric design are typically given in boundary representation (BRep), the use of parameterized volumes is essential for IGA. D...

Boundary representations (BRep) of three-dimensional solids are complex data structures that have to be created with topological and geometrical integrity. In many applications, the boundary of a solid may he specified as a list of polygons. In this paper, we consider the problem of constructing a BRep solid model from a list of polygons with the assumption that the points of each polygon lie i...

The complexity and variety of buildings the defects point cloud data are main challenges faced by 3D urban reconstruction from clouds, especially in metropolitan areas. In this paper, we developed a method that embeds multiple relations into procedural modelling process for automatic photogrammetric clouds. First, hybrid tree constructive solid geometry boundary representation (CSG-BRep) was bu...

We consider the geometric support in detecting and analyzing collisions and contact between arbitrarily shaped polyhedral objects for a physically based simulation. The contact detection is formulated as a static collisiondetection problem in three-dimensional space. We address both robustness and efficiency of the problem, and show how both can be achieved by using the brep-index data structure.

We describe a new geometric representation scheme suitable for finite element mesh generation. The representation is by boundaries (i.e., brep) and relations between boundaries are stored as a directed acyclic graph. The geometry itself is based on NURBS curves and surfaces. The new geometry proposal has been been adopted by the CornellMississippi State joint ITR project. We describe why the ge...

An object oriented data structure is presented for the purposes of finite element mesh generation. It is unique in the sense that it maintains containers of entities through an event m anager called reactable entities. This data structu re provides tight coupling with the geometric model (BRep) and user inputs to the mesh generation algorithms. It also provides a definition of a procedural clas...

This paper presents an effective method for automatic topology recovery of non-manifold geometries. Mixing topology recovery and geometry noise detection/removal allowed us to achieve effectively the automation and robustness required by such methods. We developped our method on CAD boundary representation (BREP) geometries in the context of surface mesh generation, but it could also be directl...

Nowadays, the integration of different mechanical design process stages (Design, analysis and manufacturing) of is a necessity so as to reduce the time of design and optimization. This tendency of integration CAD/CAM/Analysis and automation of the corresponding processes requires shared data between the various tasks using an integrated product model. Our research is oriented to CAD/CAM/Analysi...

Low degree (typically 2, 3) tetrahedral implicit algebraic patches are gaining in popularity for modeling boundaries of free-form (sculptured) solids. A Constructive Shell Representation (CSR) is a union of truncated tetrahedra, called \trunctets", that form a thick shell containing the boundary of such a free-form solid. One bounding face of each trunctet is an algebraic patch, and the other f...