1 General

SuperMap GIS version 10.1 supports HBase (this function has been removed since 11.2) and DSF vector data (hereinafter referred to as distributed vector data or distributed data) maps. "tile-free" is achieved by publishing as a vector tiles service through workspace. One of the advantages of vector tiles is the separation of data and style. The vector tiles of distributed vector data also follow MapBox. The style of vector tiles and tiles in MVT specification is described by MapBox standard style. Therefore, the style of some distributed vector data layers will not be supported in vector tiles; In addition, since the distributed vector data layer itself uses a new rendering display mode, the individual style settings of the original layer type (traditional vector data layer) are also invalid for the distributed vector data layer. Therefore, based on the above situation, the layer styles and related settings supported by the distributed data vector tiles are summarized as follows. It is convenient to grasp the correctness and effectiveness of the final vector tiles service display in the distributed data mapping link:

 1.1 Data coordinate system

 The display of the distributed data vector tiles service supports MapBox GL and OpenLayers rendering display effects. Among them, OpenLayers supports vector tiles rendering display of various projections, while MapBox GL only supports rendering vector tiles that display the EPSG3857 projection.

In practical mapping, if the coordinate system of data is different from the map display coordinate system, dynamic projection can be enabled to achieve correct display. It is suggested that the distributed data map publishing vector tiles service should not use dynamic projection as far as possible to ensure that the data is consistent with the map projection. Otherwise, the generation performance of vector tiles will be reduced.

 1.2 Symbolization of layers

 When using SuperMap iDesktopX carries out distributed data mapping, the symbolization of its layer and the original layer type (traditional vector data layer) share a set of symbol setting interface and symbolization system. However, because the distributed data layer adopts a new rendering display mode, there are some symbols supported by the original layer type. The distributed data layer is not supported, and when the vector tiles service is displayed, the style of the tile is described by the MapBox standard style, so the style support of the published vector tiles service is not the same as that of the distributed data map. The summary is as follows:

 1.3 Production of thematic maps

 1.4 Thematic map setting:

The vector tiles service corresponding to distributed data shows that the following unsupported content exists.

 l MapBox style does not support the offset setting of point, line and surface single-value thematic maps.

 l For the annotation field used by the label thematic map, only the native field value is supported at present, and the SQL function calculation result cannot be displayed , such as name | | '_' | | type。

 l For the same point data set, it is not supported that the single value map and label based on the point data set exist at the same time, otherwise the point symbol of the point thematic map will be lost; However, you can use multiple point ordinary layers to replace the point single-value thematic map, that is, based on the single-value field, different single-value point data are split into independent point data sets, indirectly achieving the effect of displaying different point symbols for different single-value points and displaying point labels.

 l For the same point data set, when there are both a point ordinary layer and a label thematic map based on the layer, MapBox does not support setting both the point symbol and the label background; Otherwise, the dot symbol is lost and the label remains, but the label background is offset from the label text.

 l The MapBox style only supports two display directions along the line (normal direction along the line and from top to bottom and from left to right). If the map sets other display directions along the line, the vector tiles will use "from top to bottom". Place the label in the left to right direction.

 l The text in the map needs to be set to a fixed size, otherwise, the text effect displayed by vector tiles may be different from that of the original map.

 l When the bold effect is used for the text, it is necessary to ensure that there is a bold font library of the corresponding font in the computer, so that the bold effect of the text in the generated vector tiles is effective. For example, the text uses the Microsoft Yahei font and is set to be bold. Then you should have the Microsoft Elegant Bold Font Library on your computer.

1.5 Other settings

1.6 Summary

 The mvt vector tiles service does not yet support all distributed data layer styles. For example, the mvt vector tiles service does not support system symbols well in terms of layer symbolization. However, the expected effect can be achieved indirectly in other ways. For example, if the dotted system linetype is not supported, a new linetype can be created based on the dash (system linetype), and the expected dotted linetype symbol can be obtained by adjusting the virtual and real intervals of the dash; In the aspect of thematic map, the mvt vector tiles service of the thematic map type supported by distributed data is also supported, but in the aspect of setting the thematic map, the mvt vector tiles service basically does not support it. The reason is that mvt vector tiles uses the MapBox specification, so some settings, for example, the wrapping and alignment of the label in the label thematic map are processed by the MapBox rendering engine; Therefore, in general, the mvt vector tiles service can basically support most of the distributed data layer styles.