Generate Vector Tile, an effective vector map should be prepared first, and the point, line, surface and text layers in the SuperMap map all support Generate Vector Tile. Most of the symbolization and Layer Settings of SuperMap map elements can be supported by MapBox style; However, because the MapBox style display expression is different from SuperMap, there are some limitations and precautions in the production of vector maps. The following takes the general process of map production as the main line, and introduces in detail the mapping content you need to focus on:
And that data complexity is reduce
Tile and map display differences
Data coordinate system
In the actual mapping, if the coordinate system of the data is different from the Display Coordinates of the map, you can start Dynamic Projection to display correctly, and use this map to create Vector Tile. It is recommended that the user first convert the coordinate system of the data to the map Display Coordinates system, and then Generate Vector Tile. The reason is that the coordinate system of Vector Tile data will use the map Display Coordinates system. If the coordinate system of the data is different from the map Display Coordinates system, the system will convert the coordinate system of the data when cutting the Vector Tile. Switch to the map Display Coordinates system. If the map has a large amount of data, the coordinate system conversion operation will occupy a large amount of disk space and cutting time, which will affect the efficiency of cutting.
And that data complexity is reduce
During Generate Vector Tile, in order to improve the efficiency of Tile generation and display, thinning will be carried out on the node-intensive objects during image cutting to reduce node redundancy. In most cases, this thinning will not be visually obvious, but there are also special cases, for example, the river in small scale uses planar rivers. As shown in the following figure (left figure), the river surface object has dense nodes and complex shapes. After thinning, the Vector Tile result is as shown in the following figure (right figure), and the object is obviously deformed. Therefore, it is recommended that when creating a map for cutting Vector Tile, users should ensure that the Map has reasonable complexity under different Display scales. Here, it is recommended that rivers be represented by line objects under small scales.
 |  |
| Figure: Display Effects of the line type in the left map in the right Vector Tile |
In addition, if the map features contain too many sub-objects, it will affect the cutting speed when creating Vector Tile. Therefore, it is recommended to split the sub-objects to improve the cutting efficiency.
Symbolic map
MapBox supports almost all point symbols, common line symbols such as roads, and common face Fill symbols. Maps used to create Vector Tiles should avoid complex symbols, which may not display correctly in Vector Tiles. In addition, some symbols not supported by MapBox can be replaced by the following alternatives.
The following table shows the point and line symbols and their alternatives that are not supported by the MapBox style.
Symbol Type |
SuperMap Symbol |
Vector TileDisplay Effects |
Alternative |
dot |
|
|
Create a new point symbol and draw a square Geometry to get the square point symbol. |
Line |
|
|
Create a new linetype, add dashes (system linetype) sub-lines, and adjust the Virtual-real Mode of the sub-lines to obtain the desired dashed linetype. |
Symbol Type |
SuperMap Symbol |
Vector TileDisplay Effects |
Alternative |
Line |
Line type with the following sublines: |
|
Create a new linetype, add dashes (system linetype) sub-lines, and adjust the Virtual-real Mode of the sub-lines to obtain the desired dashed linetype. |
The following table shows the Super Map face symbols and alternatives that are not supported by the MapBox style.
Symbol Type |
SuperMap Symbol |
Vector TileDisplay Effects |
alternative |
Face |
|
|
First, make these fill patterns as images; then, create a new Fill symbol and add the images as an Image Filling sub-layer. |
To sum up, the symbols not supported by MapBox are displayed as corresponding dots, solid lines and Pure Filling according to Symbol Type and Vector Tile. The MapBox style's support for area symbol outlines is exactly the same as that for line symbols.
Caution: - The display of
- Vector Tile does not support Scale Symbol.
- For custom linetypes, the MapBox style supports linetype symbols that contain multiple sublines, but each subline must be of type Default. Additionally, MapBox styles do not support Offset Settings and End Symbol settings for sublines.
- For custom Fill symbols, the MapBox style only supports Fill symbols that contain one fill sublayer, which can be Image Filling or the symbol Fill Symbol.
 |  |
| Figure: Subline Types | Supported by MapBox Style Figure: Subline Properties Dialog Box |
The effect of the text
The MapBox style also has limitations in supporting text effects in the map. Therefore, you need to pay attention to the Style Settings of all text in the map and avoid using Font Effects that are not supported by the MapBox style. The details are as follows:
text effect |
Map |
Vector Tile |
Supported or not |
bold Outline |
|
|
√ |
bold italic |
|
|
√ |
Shadow |
|
|
× |
Underline |
|
|
× |
Strikethrough |
|
|
× |
Caution: - When Generate Vector Tile, the text in the map needs to be set to Fixed Size, otherwise, the text effect displayed by Tile may be different from that of the original map.
- For a text layer, the Vector Tile uses the style of the first Text in the layer as the style of all text in the layer. When the bold and italic effects are used for the
- text, it is necessary to ensure that the bold and italic fonts of the corresponding fonts are available in the computer, so that the bold and italic effects of the text in the generated Vector Tile are effective. For example, the Microsoft YaHei font is used for the text, and bold and italic are set. You need to have both the Microsoft YaHei Bold font and the Microsoft YaHei Italic font on your computer.
 |
Create Thematic Map
Generally, thematic maps are used in the map to enrich the content expressed by the map, such as Statistic Infomation, classification information, etc. However, the MapBox style only supports thematic maps of SuperMap type. See the following table for details. If your map contains thematic maps that are not supported below, these thematic layers are ignored during Generate Vector Tile.
 |
| Figure: Support of MapBox Style for SuperMap Thematic Map |
 |  |
| Figure: Graudated Colors Map in Vector Tile | Figure: Unique-values Map in Vector Tile |
Caution: - Offset Settings for Point, Line, Face Unique-values Map are not supported by
- the MapBox style.
- For the annotation field used by the Thematic Label Map, only the native field value is supported at present, and the SQL function Calculate Result, such as name | | '_' | | type, cannot be displayed.
- In The same map, for the same point/line/regionDataset, at most one thematic map and one Thematic Label Map based on the point/line/regionDataset can exist at the same time. Otherwise, the effect will not meet the expectations.
- In the same map, for the same Point Dataset, at most one Unique-values Map based on the Point Dataset and one Unique-values Thematic Label Map can coexist. And the single-value fields for both must use the same field.
- For the same Point Dataset, when the Point Normal Layer and the Thematic Label Map made based on this layer exist at the same time, MapBox does not support setting both the point symbol and the label background, otherwise the point symbol will be lost and the label will be retained. But the label background will be offset from the label text.
- MapBox style only supports two display directions along the line (i.e. "Along the normal of the line" and "Top to bottom, left to right"). The Vector Tile will use the Top to bottom left to right "the Display Method.
Limited visible scale
Usually, in order to improve the map display performance, we will Set Visible Scale for the layer, which can also improve the drawing efficiency of Vector Tile in Vector Tile application. Vector Tile is created with the Global scale, so you can adjust the visible scale range of each layer in the vector map with reference to the Global scale.
About Layers Display Filter
The objects in the layer can be filtered and displayed by setting the layer display Filter. Currently, Vector Tile only supports some Filter Expressions, including simple logical operators (And, Or, Not) and comparison operators (=, >, <,! =).
- Comparison Operators: Example 1: GDP _ 2014 < = 10000; Example 2: PAC = 140502; Example 3: pop _ 2014 < 950; Example 4: PAC! = 140502。
- Logical operators: Example 1: pop _ 2014 > 4000 And GDP _ 2014 > 15039.38; Example 2: PAC = 131028 Or PAC = 140502; Example 3: Not PAC = 140502.
Caution: - Table name cannot be added before Field in
- Filter Expression, that is, "China _ Province. Pop _ 2014" is not supported. 3833 "is an expression with a table name.".
- Currently, only numeric values are supported for the values involved in the comparison and judgment of expressions, and text or characters are not supported at present, that is, expressions such as "NAME = 'Sichuan'" are not supported.
Tile and map display differences
Because the MapBox style display expression is different from SuperMap, there are differences in some map display details. The following shows you the main display differences between the two to help you clearly understand the results of Vector Tile generation. The following screenshots all show the Vector Tile using MapBox GL rendering.
- Typesetting: MapBox handles wrapping for long tags differently than SuperMap. Display Effects in the Tile are quite different from the map after the Generate Vector Tile when the settings for label wrapping and the settings for multi-line text typesetting are applied to the Thematic Label Map.
Map
Vector Tile
New Line Display, 16 words in a single line of text , Center Alignment in multiple lines of text
The location of
New Line Display is different
from the map
Set label text Single Line Display.
New Line Display
- Label Alongline: MapBox handles Label Alongline differently from SuperMap. Therefore, the Label Alongline effect displayed by Vector Tile is different from that of the original map.
Map
Vector Tile
Set Label Alongline character spacing by 1.3 times
Label Alongline is
closely spaced
The number of
Label Alonglines and where they appear are different
from the map - Avoidance and Overlap Settings: The avoidance processing of MapBox for features in the map is different from that of SuperMap, resulting in differences in the number of labels displayed, labels and alignments, etc. In addition, the Overlap Settings of the SuperMap map are not valid when the Vector Tile is displayed.
Figure: Vector Tile does not support map Over lap Settings.
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