Mapbox Vector Tile (MVT) and MVT Tileset Reader/Writer

Mapbox Vector Tile (MVT). Reads single files from the local file system. The reader can also accept URLs and read single files or entire tilesets when the URL ... SkipToMainContent Account Settings Logout placeholder Account Settings Logout Filter: AllFiles SubmitSearch MapboxVectorTile(MVT)andMVT TilesetReader/Writer LicensingoptionsforthisformatbeginwithFME DesktopProfessionalEdition. Overview FMEprovidesreadandwriteaccessforMapboxVectorTile(MVT)tilesandtilesets.FME canreadfromawebaddress,alocalfile,oralocalfolder;andcanwritetoalocalfolder. Tilesarespatiallyrelatedcollectionsofvectorfeaturesthatcanbestoredononeormorelayers.Tilescanalsobestoredingroupscalledtilesetsthatcontaintilesatthesamezoomlevel.Thetilesarecontainedwithin.mvtfilesorcompressed.mvt.gzfiles. Layersareusedtosemanticallygroupdifferentvectorfeatures,andtheycanspanmultipletiles(forexample,rivers,roads,orvectorfeatureswithinacity). ReaderOverview TheMVTreadersupportsreadingmultipleoneormorevectortilesfromaURLorlocalfilesystem.Eachtilemaycontainanynumberofvectorfeaturesofanysupportedgeometrytype,whichthenbecomefeaturesinFME. ThevectorfeaturesareclassifiedintodifferentlayerswhosenamesandattributesbecomefeaturetypenamesandattributesinFME.Layerscanbedefinedinanoptionalmetadata.jsonfileattherootofatilesetwhichisreadautomaticallywhentilesareconfiguredinatilescheme. TworeadersexistfordifferenttypesofMVTdatasets:MapboxVectorTile(MVT),andMapboxVectorTile(MVT)Tileset.Thefeaturesofeachreaderaredescribedinthetablebelow. MapboxVectorTile(MVT) Readssinglefilesfromthelocalfilesystem.ThereadercanalsoacceptURLsandreadsinglefilesorentiretilesetswhentheURLonlyspecifiesazoomlevel.Forexample,https://b.tiles.mapbox.com/v4//15willreadallthetilesinthespecifiedmapatzoomlevel15. SelectthereaderMapboxVectorTile(MVT)whenthedatasetisafileorURL: Filewiththeextensions.mvtor.mvt.gz. URLaddresstoatileoratileset(forexample,http[s]://path/to/some.mvtforasingletileandhttp[s]://path/to/{Z}foratileset,whereZisthedesiredzoomlevel). MapboxVectorTile(MVT)Tileset Readstilesetsthatareinthespecifieddirectoryzoomlevel.Thedirectoryhierarchyforatilesetmustconformtothestructurespecifiedintheformatusagenotes–otherwise,themetadatamaynotbereadcorrectly. SelectthereaderMapboxVectorTile(MVT)Tilesettoreadalocalfolder. Eachlayerinthevectortilecorrespondswithitsownfeaturetype.Atilemayhavemultiplelayersandthereforemultiplefeaturetypes. Dataset ThedatasetcanbeanMVTfilewithextension.mvtor.mvt.gz,oritcanbeaURLaddresstoatileoratileset(forexample,http[s]://path/to/some.mvtforasingletileandhttp[s]://path/to/{Z}foratileset,whereZisthedesiredzoomlevel). SeeUsageNotesforfurtherinformation. WriterOverview TheMVTwritergeneratestilesintheWebMercator(EPSG:3857)projectionbydefault. Thewriteracceptsinputvectorfeaturesfromvariouslayersandtilesthemupintoabasezoomlevel.Subsequentlower-resolutionzoomlevelsmayalsobegeneratedfromthebasezoomlevel.Eachzoomlevelisauniquetilesetthatcanbereadtogether,orasindividualtiles.Severalsemanticlayersofvectorfeaturesmaybewrittentoeachfileandzoomlevel. Dataset Thedatasetisanoutputfolderintowhichthewriterwillcreateonetilesetperapplicablezoomlevelrequestedinthenewfolder. Note:IfOverwriteFolderissettoYes,theoutputfolderisdeletedandrecreatedtopreventincorrecttilesetcreationwhenreusingtheexistingfolder.Thismeansexistingdatainthefolderwillbedeleted.(IfOverwriteFolderissettoNo,thewriterwillreturnanerrorifthedatasetisanon-emptyfolder.) ThesefolderscorrespondtotheMVTtiledirectoryspecification,/{Z}/{X}/{Y}.,where{Z}isazoomlevelbetween0and22,and{X}and{Y}arethetileindexeswithinthetilespecification. Example TheMVTwriterreceivesinputvectordataforcountriesoftheworld,andhasthefollowingparameters: anoutputdatasetofc:/output, minandmaxzoomlevelsof0and0,and atileextensionof.mvt. Wewouldexpectthefollowingoutputfolderandfiles: c:/output/0/0/0.mvt c:/output/0/0/1.mvt c:/output/0/0/2.mvt c:/output/0/0/3.mvt c:/output/0/1/0.mvt c:/output/0/1/1.mvt c:/output/0/1/2.mvt c:/output/0/1/3.mvt SeeUsageNotesforfurtherinformation. Toreadatilesetinalocalfolder,pleaseusetheMapboxVectorTile(MVT)Tilesetreader,whichacceptsfoldersasdatasets.NotethatwhiletheMVTwritercreatesmultipletilesets,theMVTreadertypicallyonlyreadsoneatatime. AreOpenStreetMapPBFfilesrelatedtoMapboxVectorTiles? Theyarenotrelated.PBFsareaformat–muchlikeXML–andcantakemanyforms.MapboxVectorTilesandOpenStreetMapPBFsareprotobuffiles,buttheyconformtodifferentspecificationsandprotobufschemas,andtheyareusedindifferentways.FME doesnotusethisextension,butotherMVT providersmight. HowFMEWorkswithMVTData Toaccessvectordata,ithelpstosubdividethedataintosmallertilesaccordingtoawell-knowntilingscheme,andstoreeachtile.MapBoxhascreatedtheMVTtileschematostoretilesandtilesetsatdifferentzoomlevelsandaccessthemoneitheraserverorlocalhost.Thesetilesarestoredinefficientprotocolbufferfiles,vectortilesfiles,orcompressedvectortilesfiles.SeeGDAL Documentation–MVTformoreinformationonMVTfilestructure. FMEcanreadandanalyzeindividualtilesortilesets,filterthem,organizethem,andthenoutputtheresultsintoanewtileset,oranyothervectorformat.FMEcanalsointegratevectorfeaturedatafromotherformats(forexample,GIS,CAD,oranyothervectordata)intoaneworexistingtileset. TerminologyinthisChapter Term DefinitionorFME Representation tile readerdataset tileset readerorwriterdataset layer featuretype field/attribute attribute feature feature UsageNotes FMEsupportsreadingMapBoxVectorTilesspecificationversion1.xand2.x,andwritingversion2.1. TheMVTreaderusesthreeintegercoordinates,wherezisthezoomleveland(x,y)isthecoordinateofthetileinthezoomlevel. TheMVTwriterusesthejsonkeyfromthemetadata.jsonfiletopopulatefeaturetypenames,attributenamesandtypes,andthegeometrytype.Theboundskeyisalsousedforthefeaturetypeextents.Allothercontentsofthemetadata.jsonfileareunused.Ifametadata.jsonfilecannotbefound,thefeaturetypeschemaisestablishedbyscanningthefeaturesofthetile(s). Ifametadata.jsonfilecannotbefound,thefeaturetypeschemaisestablishedbyscanningthefeaturesofthetile(s). Eachlayerinthevectortilecorrespondstoitsownfeaturetype.ATilemayhavemultiplelayers,andthereforemultiplefeaturetypes.