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B-rep
In solid modeling and computer-aided design, boundary representation (often abbreviated B-rep or BREP) is a method for representing a 3D shape by defining the limits of its volume. A Solid modeling, solid is represented as a collection of connected Surface (mathematics), surface elements, which define the boundary between interior and exterior points. Overview A boundary representation of a model comprises topology, topological components (face (geometry), faces, edge (geometry), edges and vertex (geometry), vertices) and the connections between them, along with geometric definitions for those components (surfaces, curves and points, respectively). A face is a bounded portion of a Computer representation of surfaces, surface; an edge is a bounded piece of a curve and a vertex lies at a point. Other elements are the ''shell'' (a set of connected faces), the ''loop'' (a circuit of edges bounding a face) and ''loop-edge links'' (also known as ''winged edge links'' or ''half- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cascade Technology
Open Cascade Technology (OCCT, formerly named CAS.CADE) is an object-oriented C++ class library for 3D computer-aided design (CAD), computer-aided manufacturing (CAM), computer-aided engineering (CAE), etc. It is developed and supported by Open Cascade SAS company. It is free and open-source software released under the GNU Lesser General Public License (LGPL), version 2.1 only, which permits open source and proprietary uses. OCCT is a full-scale boundary representation (B-rep) modeling toolkit. History ''CAS.CADE'' (abbreviated from Computer Aided Software for Computer Aided Design and Engineering) was originally developed in the early 1990s by Matra Datavision, developer of Euclid CAD software as the underlying infrastructure for its future version Euclid Quantum. In 1998 the company abandoned software development to concentrate on services, and most of the software development facilities were sold to Dassault Systèmes, developer of competing CATIA. Open sourcing In 1999 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGES
The Initial Graphics Exchange Specification (IGES) is a vendor-neutral List of file formats, file format that allows the CAD data exchange, digital exchange of information among computer-aided design (CAD) systems. It is an ASCII-based textual format. The official title of IGES is ''Digital Representation for Communication of Product Definition Data'', first published in March, 1980 by the U.S. National Bureau of Standards as NBSIR 80-1978. Many documents (like early versions of the Defense Standards MIL-PRF-28000 and MIL-STD-1840) referred to it as American Society of Mechanical Engineers, ASME Y14.26M, the designation of the ANSI committee that approved IGES Version 1.0. Using IGES, a CAD user can exchange product data models in the form of circuit diagrams, wire frame model, wireframe, freeform surface modelling, freeform surface, Boundary representation, boundary (B-rep) or solid modeling (CSG) Representation (arts), representations. Applications supported by IGES include tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer-aided Design
Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. Designs made through CAD software help protect products and inventions when used in patent applications. CAD output is often in the form of electronic files for print, machining, or other manufacturing operations. The terms computer-aided drafting (CAD) and computer-aided design and drafting (CADD) are also used. Its use in designing electronic systems is known as ''electronic design automation'' (''EDA''). In mechanical design it is known as ''mechanical design automation'' (''MDA''), which includes the process of creating a technical drawing with the use of computer software. CAD software for mechanical design uses either vector-based graphics to depict t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volumetric Models
In 3D computer graphics and modeling, a volumetric mesh is a polyhedral representation of the interior region of an object. It is unlike polygon meshes, which represent only the surface as polygons. Applications One application of volumetric meshes is in finite element analysis, which may use regular or irregular volumetric meshes to compute internal stresses and forces in an object throughout the entire volume of the object. Volume meshes may also be used for portal rendering. See also * B-rep * Voxels * Hypergraph * Volume rendering In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set, typically a 3D scalar field. A typical 3D data set is a group of 2D slice image ... References 3D computer graphics Computer graphics data structures Mesh generation {{mathapplied-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACIS
The 3D ACIS Modeler (ACIS) is a geometric modeling kernel developed by Spatial Corporation (formerly Spatial Technology), part of Dassault Systèmes. ACIS is used by software developers in industries such as computer-aided design, computer-aided manufacturing, computer-aided engineering, architecture, engineering and construction, coordinate-measuring machine, 3D animation, and shipbuilding. ACIS provides software developers and manufacturers the underlying 3D modeling functionality. ACIS features an object-oriented C++ architecture with 3D modelling capabilities. ACIS is used to construct applications with hybrid modeling features, since it integrates wireframe model, surface, and solid modeling functionality with both manifold and non-manifold topology, and a set of geometric operations. History As a geometric kernel, ACIS is a second generation system, coming after the first generation Romulus. There are several versions about what the word ACIS actually stands f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cambridge
The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, world's third-oldest university in continuous operation. The university's founding followed the arrival of scholars who left the University of Oxford for Cambridge after a dispute with local townspeople. The two ancient university, ancient English universities, although sometimes described as rivals, share many common features and are often jointly referred to as Oxbridge. In 1231, 22 years after its founding, the university was recognised with a royal charter, granted by Henry III of England, King Henry III. The University of Cambridge includes colleges of the University of Cambridge, 31 semi-autonomous constituent colleges and List of institutions of the University of Cambridge#Schools, Faculties, and Departments, over 150 academic departm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combinatorial Maps
A combinatorial map is a combinatorial representation of a graph on an orientable surface. A combinatorial map may also be called a combinatorial embedding, a rotation system, an orientable ribbon graph, a fat graph, or a cyclic graph. More generally, an n-dimensional combinatorial map is a combinatorial representation of a graph on an n-dimensional orientable manifold. Combinatorial maps are used as efficient data structures in image representation and processing, in geometrical modeling. This model is related to simplicial complexes and to combinatorial topology. A combinatorial map is a boundary representation model; it represents object by its boundaries. History The concept of a combinatorial map was introduced informally by J. Edmonds for polyhedral surfaces which are planar graphs. It was given its first definite formal expression under the name "Constellations" by A. Jacques but the concept was already extensively used under the name "rotation" by Gerhard Ringel and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bézier Surface
Bézier surfaces are a type of mathematical spline used in computer graphics, computer-aided design, and finite element modeling. As with Bézier curves, a Bézier surface is defined by a set of control points. Similar to interpolation in many respects, a key difference is that the surface does not, in general, pass through the central control points; rather, it is "stretched" toward them as though each were an attractive force. They are visually intuitive and, for many applications, mathematically convenient. History Bézier surfaces were first described in 1962 by the French engineer Pierre Bézier who used them to design automobile bodies. Bézier surfaces can be of any degree, but bicubic Bézier surfaces generally provide enough degrees of freedom for most applications. Equation A given Bézier surface of degree (''n'', ''m'') is defined by a set of (''n'' + 1)(''m'' + 1) control points k''i'',''j'' where ''i'' = 0, ..., ''n'' and ''j'' = 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bézier Curve
A Bézier curve ( , ) is a parametric equation, parametric curve used in computer graphics and related fields. A set of discrete "control points" defines a smooth, continuous curve by means of a formula. Usually the curve is intended to approximate a real-world shape that otherwise has no mathematical representation or whose representation is unknown or too complicated. The Bézier curve is named after France, French engineer Pierre Bézier (1910–1999), who used it in the 1960s for designing curves for the bodywork of Renault cars. Other uses include the design of computer fonts and animation. Bézier curves can be combined to form a Composite Bézier curve, Bézier spline, or generalized to higher dimensions to form Bézier surfaces. The Bézier triangle is a special case of the latter. In vector graphics, Bézier curves are used to model smooth curves that can be scaled indefinitely. "Paths", as they are commonly referred to in image manipulation programs, are combinations of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-spline
In numerical analysis, a B-spline (short for basis spline) is a type of Spline (mathematics), spline function designed to have minimal Support (mathematics), support (overlap) for a given Degree of a polynomial, degree, smoothness, and set of breakpoints (Knot (mathematics), knots that partition its Domain of a function, domain), making it a fundamental building block for all spline functions of that degree. A B-spline is defined as a piecewise polynomial of Order (mathematics), order n, meaning a degree of n - 1. It’s built from sections that meet at these knots, where the continuity of the function and its Derivative, derivatives depends on how often each knot repeats (its multiplicity). Any spline function of a specific degree can be uniquely expressed as a linear combination of B-splines of that degree over the same knots, a property that makes them versatile in mathematical modeling. A special subtype, cardinal B-splines, uses equidistant knots. The concept of B-splines tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 10303
ISO 10303 (Automation systems and integration — Product data representation and exchange)ISO 10303-1:1994 Industrial automation systems and integration -- Product data representation and exchange -- Part 1: Overview and fundamental principles is a family of ISO standards for computer-interpretable representation (description) and exchange of product manufacturing information (PMI). It aims to provide interoperability between various computer-aided design (CAD) software, assist with automation in computer-aided manufacturing (CAM), and allows long-term archival of 3D, CAD and PDM data. It is known informally as "STEP", which stands for "''Standard for the Exchange of Product model data''". Due to a large scope ISO 10303 is subdivided into approximately 700 underlying standards total. The standard includes Parts 11-18 and Part 21 that describe EXPRESS data schema definition language and STEP-file (also STEP-XML) used for textual representation of PMI data codified by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
