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The Esri TIN format is a popular yet proprietary geospatial vector data format for geographic information system (GIS) software for storing elevation data as a triangulated irregular network. It is developed and regulated by Esri. The Esri TIN format can spatially describe elevation information including breaking edge features. Each points and triangle can carry a tag information. A TIN stored in this file format can have any shape, cover multiple regions (e.g. islands) and contain holes (e.g. lakes).〔(【引用サイトリンク】url=http://www.utdallas.edu/~briggs/poec6382/surfaces.ppt )〕 In 2007 a reverse-engineered description of Esri TIN format came to light.〔(【引用サイトリンク】url=http://vterrain.org/Implementation/Formats/ITF.html )〕 Since then, the Virtual Terrain Project, an open-source software, has implemented support for reading the format, without the need of ArcGIS being installed.〔(【引用サイトリンク】url=https://code.google.com/p/vtp/source/browse/trunk/TerrainSDK/vtdata/vtTin.cpp )〕 == Overview == The Esri TIN format is a digital vector storage format for storing elevation information including breaking edge features. The Esri TIN format was introduced with ArcView GIS. The Esri TIN format consists of a collection of files with specific filenames and a common filename extension, stored in the same directory. Most of the files are ''mandatory'' files (tdenv.adf, tedg.adf, thul.adf, tmsk.adf, tmsx.adf, tnod.adf,〔 tnxy.adf〔 and tnz.adf〔), optionally a file containing the coordinate system and projection information (prj.adf) and files containing point tag information (tnval.adf and tndsc.adf) and triangle tag information (ttval.adf and ttdsc.adf)〔〔 can be given. ;Mandatory files : * tdenv.adf — header and statistical data * tedg.adf — edges data and topology * thul.adf — outer and inner hull polygon data * tmsk.adf — mask data, masks invisible triangles * tmsx.adf — index file for tmsk.adf * tnod.adf — triangle node data * tnxy.adf — position informations (x and y coordinates) * tnz.adf — height informations (z values) The endianness of most of the files is big-endian. tmsk.adf, tmsx.adf and tdenv.adf have mixed endianness. ;Other files : * prj.adf — projection format; the coordinate system and projection information, a plain text file describing the projection using well-known text format; are single line signifies an unknown coordinate system〔(【引用サイトリンク】url=http://code.nicholas.duke.edu/projects/mget/export/980/MGET/Trunk/PythonPackage/dist/TracOnlineDocumentation/Documentation/PythonReference/Method_GeoEco.DataProducts.HYCOM._HYCOMGridGOMl0044D.ConvertSpatialReference.html?format=raw )〕 * tndsc.adf — statistic on point tag usage * tnval.adf — point tag data * ttdsc.adf — description of triangle tag data * ttval.adf — triangle tag data The endianness of the file tndsc.adf and tnval.adf is little-endian. ;Files generated by ArcGIS 10 : * tnodinfo.adf — point types and more * teval.adf — edges data * tdenv9.adf — the file tdenv.adf renamed ;Size of file A TIN with n points (incl. superpoints) and k triangles, the file sizes calculate to: * tnxy.adf : 16 *n bytes * tnz.adf : 4 *n bytes * tnod.adf : 12 *k bytes * tedg.adf : 12 *k bytes * tmsx.adf : 116 bytes * tdenv.adf/tdenv9.adf : 104 bytes * tmsk.adf : 132 + 4 *ceiling(n/32) bytes * thul.adf : min. 12 bytes, depends on the number of points in the convex hull polygon * tndsc.adf : 24 * the number of tag entries specified in tndsc.adf bytes (see below) * tnval.adf : 4 *n' bytes (n': number of tagged points, incl. superpoints; see below) * tnodinfo.adf : 2 *n bytes * teval.adf : 16 * the number of breaking edges entries specified in tdenv9.adf bytes (see below) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Esri TIN」の詳細全文を読む スポンサード リンク
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