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CityGML
CityGML is an open standardised data model and exchange format to store digital 3D models of cities and landscapes. It defines ways to describe most of the common 3D features and objects found in cities (such as buildings, roads, rivers, bridges, vegetation and city furniture) and the relationships between them. It also defines different standard levels of detail (LoDs) for the 3D objects, which allows the representation of objects for different applications and purposes, such as simulations, urban data mining, facility management, and thematic inquiries. CityGML is implemented as a GML application schema for the Geography Markup Language 3 (GML3), the extendible international standard for spatial data exchange issued by the Open Geospatial Consortium (OGC) and the ISO TC211. Implementations In its most common implementation, which is the one generally used to disseminate and exchange data, CityGML datasets consist of a set of XML files and possibly some accompanying image fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D City Models
A 3D city model is digital model of urban areas that represent terrain surfaces, sites, buildings, vegetation, infrastructure and landscape elements in three-dimensional scale as well as related objects (e.g., city furniture) belonging to urban areas. Their components are described and represented by corresponding two- and three-dimensional spatial data and geo-referenced data. 3D city models support presentation, exploration, analysis, and management tasks in a large number of different application domains. In particular, 3D city models allow "for visually integrating heterogeneous geoinformation within a single framework and, therefore, create and manage complex urban information spaces." Storage To store 3D city models, both file-based and database approaches are used. There is no single, unique representation schema due to the heterogeneity and diversity of 3d city model contents. Encoding of components The Components of 3D city models are encoded by common file and excha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Markup Language
The Geography Markup Language (GML) is the XML grammar defined by the Open Geospatial Consortium (OGC) to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet. Key to GML's utility is its ability to integrate all forms of geographic information, including not only conventional "vector" or discrete objects, but coverages (see also GMLJP2) and sensor data. GML model GML contains a rich set of primitives which are used to build application specific schemas or application languages. These primitives include: * Feature * Geometry * Coordinate reference system * Topology * Time * Dynamic feature * Coverage (including geographic images) * Unit of measure * Directions * Observations * Map presentation styling rules The original GML model was based on the World Wide Web Consortium's Resource Description Framework (RDF). Subsequently, the OGC introduced XML schemas in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Level Of Detail (computer Graphics)
In computer graphics, level of detail (LOD) refers to the complexity of a 3D model representation. LOD can be decreased as the model moves away from the viewer or according to other metrics such as object importance, viewpoint-relative speed or position. LOD techniques increase the efficiency of rendering by decreasing the workload on graphics pipeline stages, usually vertex transformations. The reduced visual quality of the model is often unnoticed because of the small effect on object appearance when distant or moving fast. Although most of the time LOD is applied to geometry detail only, the basic concept can be generalized. Recently, LOD techniques also included shader management to keep control of pixel complexity. A form of level of detail management has been applied to texture maps for years, under the name of mipmapping, also providing higher rendering quality. It is commonplace to say that "an object has been ''LOD-ed''" when the object is simplified by the underlying ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Model
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner. The term data model can refer to two distinct but closely related concepts. Sometimes it refers to an abstract formalization of the objects and relationships found in a particular application domain: for example the customers, products, and orders found in a manufacturing organization. At other times it refers to the set of concepts used in defining such formalizations: for example concepts such as entities, attributes, relations, or tables. So the "data model" of a banking application may be defined using the entity-relationship "data model". This article uses the term in both senses. A data model explicitly determines the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Elevation Model
A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top canopy or building roofs. While a DSM may be useful for landscape modeling, city modeling and visualization applications, a DTM is often required for flood or drainage modeling, land-use studies, geological applications, and other applications, and in planetary science. Terminology There is no universal usage of the terms ''digital elevation model'' (DEM), ''digital terrain model'' (DTM) and ''digital surface model'' (DSM) in scientific literature. In most cases the term ''digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GML Application Schema
GML may refer to: Computing * Game Maker Language, the scripting language of Game Maker * Generalized Markup Language, a set of macros for the IBM text formatter, SCRIPT * Generative Modelling Language, an extension of PostScript used for the concise description of complex 3D shapes * Geography Markup Language, an XML grammar to express geographical features * Graffiti Markup Language, an XML-based file format that stores graffiti motion data * Graph Modelling Language, a hierarchical ASCII-based file format for describing graphs Other uses * Canadian Gold Maple Leaf, a gold bullion coin * Gilmala Halt railway station (station code), in Pakistan * GML Heritage, an Australian heritage consultancy firm * Hostomel Airport (IATA code), in Ukraine * Gradient multilayer nanofilm, a nanomaterial * Grand Medal of Lotus Flower, an honour of Macau * Guardian Media Limited, a Trinidadian media company * Middle Low German Middle Low German or Middle Saxon (autonym: ''Sassisch'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Geospatial Consortium
The Open Geospatial Consortium (OGC), an international voluntary consensus standards organization for geospatial content and location-based services, sensor web and Internet of Things, GIS data processing and data sharing. It originated in 1994 and involves more than 500 commercial, governmental, nonprofit and research organizations in a consensus process encouraging development and implementation of open standards. History A predecessor organization, OGF, the Open GRASS Foundation, started in 1992. From 1994 to 2004 the organization also used the name Open GIS Consortium. The OGC website gives a detailed history of the OGC. Standards Most of the OGC standards depend on a generalized architecture captured in a set of documents collectively called the ''Abstract Specification'', which describes a basic data model for representing geographic features. Atop the Abstract Specification members have developed and continue to develop a growing number of specifications, or ''stand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO TC211
ISO/TC 211 is a standard technical committee formed within ISO, tasked with covering the areas of digital geographic information (such as used by geographic information systems) and geomatics. It is responsible for preparation of a series of International Standards and Technical Specifications numbered in the number range starting at ISO-19101. The Chair of the committee was 1994-2016: Olaf Østensen; during 2017-2018: Christina Wasström; and from 2019 Agneta Gren Engberg. Scope ISO/TC 211 is concerned with the standardization in the field of digital geographic information. This work aims to establish a structured set of standards for information concerning objects or phenomena that are directly or indirectly associated with a location relative to the Earth. Project specification areas within the ISO/TC 211 technical committee include: * Simple Features access * Reference models * Spatial and temporal schemas * Location-based services * Metadata * Web feature and map s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GitHub
GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. Headquartered in California, it has been a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. As of June 2022, GitHub reported having over 83 million developers and more than 200 million repositories, including at least 28 million public repositories. It is the largest source code host . History GitHub.com Development of the GitHub.com platform began on October 19, 2007. The site was launched in April 2008 by Tom Preston-Werner, Chris Wanstrath, P. J. Hyett and Scott Chacon after it had been made available for a few months prior as a beta release. GitHub has an annual keynote called GitHub Universe. Organizational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESRI Shapefile
The shapefile format is a geospatial vector GIS file formats, data format for geographic information system (GIS) software. It is developed and regulated by Esri as a mostly open standard, open specification for data interoperability among Esri and other Geographic information system, GIS software products. The shapefile format can spatially describe Vector graphics, vector features: Point (geometry), points, polyline, lines, and polygons, representing, for example, water wells, rivers, and lakes. Each item usually has Attribute (computing), attributes that describe it, such as ''name'' or ''temperature''. Overview The shapefile format is a digital vector storage format for storing geographic location and associated attribute information. This format lacks the capacity to store Geospatial topology, topological information. The shapefile format was introduced with ArcView 3.x, ArcView GIS version 2 in the early 1990s. It is now possible to read and write geographical datasets u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GIS Vector File Formats
A geographic information system (GIS) is a type of database containing geographic data (that is, descriptions of phenomena for which location is relevant), combined with software tools for managing, analyzing, and visualizing those data. In a broader sense, one may consider such a system to also include human users and support staff, procedures and workflows, body of knowledge of relevant concepts and methods, and institutional organizations. The uncounted plural, ''geographic information systems'', also abbreviated GIS, is the most common term for the industry and profession concerned with these systems. It is roughly synonymous with geoinformatics and part of the broader geospatial field, which also includes GPS, remote sensing, etc. Geographic information science, the academic discipline that studies these systems and their underlying geographic principles, may also be abbreviated as GIS, but the unambiguous GIScience is more common. GIScience is often considered a subdisc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
