Single-task cutting graph

Instructions for use

Single-task graph cutting, namely single-task Generate Map Tiles, means that only a single process is started to complete the graph cutting task, the process calls one graph cutting task at a time, and after the Current Task is finished, the subsequent tasks are called in turn to execute the graph cutting.

It is suitable for the cutting requirements of small map data volume and small cutting scale.

Before Generate Map Tiles, Application will check the index of the Dataset, and will prompt the user to Create Spatial Index when the number of data objects is greater than 2000 and No Spatial Index. It is recommended that you DatasetCreate Map Index on the map in advance to improve the generation rate of Map Tiles.

Function entrance

Workspace Manager-> Map node-> Map Context Menu requiring Generate Map Tiles-> Generate Map Tiles (single task) item.
Right click Map and select Generate Map Tiles (Single Task).
Map tab-> Drawing group-> Single task.

Operating instructions

Create New Task: In the Generate Map Tiles (Single Task) dialog box, you can select three single-task cutting methods: Create New Task, Update/Append Tiles, and Resume/Restore Tiles. Select the Create New Task item here.
To perform Performance Diagnosis on a map, check the Diagnose check box on the Generate Map Tiles (Single Task) dialog. Perform Performance Diagnosis on the Current Map, and select whether to continue to cut the map according to the diagnosis result. If the diagnosis result is not ideal, the map can be optimized, and then the Start to generate tiles function can be used to improve the efficiency of map cutting.
Set scale information: Set the scale parameters of Generate Tiles in the Single Task: Generate Map Tiles dialog box. The program will automatically generate a list of scales according to the map data. You can modify the scale information through the scale toolbar, including switching the scale scheme, Add Scale, and importing the Export ScaleConfig File or Tile Config File.

Parameter Settings：

Caution:

Only the parameter information of Raster Tile is introduced

here. For the Parameter Settings of Vector Tile, please refer to Vector Tile .

Tile Type:: Raster Tile and Vector Tile formats are provided. Select Raster Tile here. For more details on Raster Tile and Vector Tile, see Tile Type: .

Tile format: Support five image formats: JPG, PNG, JPG _ PNG, PNG 8 and WEBP. The default is WEBP format. A description of each format is as follows:

Explain	Data Type
JPG	Full name JPEG, stores a single raster picture in 24-bit color. The JPEG format is platform-independent and supports the highest level of compression, however, it is lossy. Setting Background Transparency is not supported.
PNG	Portable Network Graphics is a bitmap format that uses a lossless compression algorithm. Support setting of Background Transparency, which is not checked by default.
JPG_PNG	JPG _ PNG mixed types. Use PNG format at the data boundary, and use JPG format where there is no invalid data. This will greatly reduce the size of Cache Data, thus optimizing the data download time. Background Transparency is forced to be checked.
PNG8	The 256-color PNG format has a smaller storage space, which is about half of the PNG Picture Size. The generated result is a simple picture with fewer colors and stronger contrast. It supports the setting of Background Transparency, which is not checked by default.
WEBP	Is a new Picture File format that reduces file size while achieving the same picture quality as the JPeg format. Compared with PNG format, it has smaller image size, supports Alpha transparency and 24-bit color number, improves page loading speed and reduces storage requirements. Support the setting of Background Transparency, which is not checked by default.

Background Transparency: When Background is set in Map Properties, if this item is checked, the background color will be set to be transparent during Generate Map Tiles, and only the color of the layer will be retained; When the Tile of Overlay Generate is required to be displayed or merged, it is recommended to check the Background Transparency option, otherwise a solid border overlay will appear.
The size of tiles (PX): The size of each generated Tile in PX (pixels). Five sizes of 1024 * 1024, 512 * 512, 256 * 256, 128 * 128 and 64 * 64 are provided, and the Default Size is 256 * 256.
Tile compression ratio: Quality compression is applied to the generated tiles. The default value is 75. That is, 100M. If the Tile compression ratio is set to 75, the compression result is 75M. The compression ratio is the best state of image clarity and image quality under the default value verified by the laboratory test. If a higher value is selected, the image quality will be higher, but the file will be larger. Using a lower value, the image quality is lower and the file size is smaller. If users have higher requirements for Tile quality and Tile volume, it is recommended to generate Tile in WEBP format.
- when Tile format is WEBP;
- When the Tile format is PNG, PNG 8, or JPG _ PNG, the value range of Tile compression ratio is: (0, 90;
- When the image type is JPG, the value range of Tile compression ratio is: 10,100;
Resolution: Support the setting of Tile resolution, so that the user can customize the output accuracy of the Tile. The default resolution is 96 DPI.
Ignore Invalid Data: Invalid data refers to the map area that does not contain any content. If this check box is checked, the program will ignore the invalid area and will not generate a Tile at the corresponding location. If only the land has data when generating Global Tile, this parameter can be checked to reduce the generation of Tile outside the land and reduce the volume of TileResult Storage. The parameter is not available when the map contains a WebDataset or Tile Layer.
Base Scale: The scale of the finest layer display of the Image Map (i.e., the Zoom to Image Resolution display) is called the base scale. Check this parameter to determine the scale of Generate Tiles based on the scale. The base scale only supports setting when the map layer is a grid or Mosaic Layer, and the Vector Layer in the Mosaic Layer remains invisible.

Save Settings:
- Tile Name: The name of the Generate Tiles folder, which is Map Name by default. When a tile with this name already exists in the storage directory, click Next and you will be prompted that the "China100 _ 2021" file already exists. Please re-enter the Tile Name or the storage directory.
- Storage Format: provides three Storage Formats: Compact, Original, and MongoDB. Compact Storage Format is selected by default. See the TileS torage Format for the Detail Description of the storage type.
  
  Caution:
  
  The authentication mode
  of MongoDB version 2.0 does not support Generate Map Tiles. Please refer to the MongoDB Instructions for use for MongoDB database usage.
  - When raw and compact are selected, the storage method needs to be set.
  - When compact is selected, it can be TileSet Password to ensure data security.
  - When selecting MongoDB, you need to set the server address and Database Name, and you can select whether to use TileSet Password.
- Storage Mode: The storage mode of Generate Tiles, including Local and Cloud Storage.
  - Select Local. The generated Tile and intermediate files will be stored in the local path specified in the storage directory.
  - If you select cloud storage, you can select a cloud storage path in the storage directory to store Tile files. You need to Add Cloud Storage Connection before using the cloud storage path; At the same time, the working directory needs to be set, and the intermediate files generated in the process of cutting will be stored in the local path specified by the working directory.

Storage Directory: the storage path of Generate Tiles.
Working Directory: The storage method needs to be set when selecting cloud storage or Storage Format and selecting MongoDB. It is used to store the intermediate files generated in the process of graph cutting, so as to facilitate the continuation and update of Tile.

Tile Bounds : Set the Geographic Range of the map data, and the program will Generate Map Tiles according to this range. The following settings are available:
- Whole Map: Use the range of Whole Map as Tile Bounds, and the four text boxes at the bottom left and top right are used to display the set processing range;
- Current Windows: Use the range of Current Windows as the Tile Bounds.
- Custom Bounds: Click the Drop-down Button to select Select Object, Draw Rectangle, or Custom Expression to customize Tile Bounds.
  - Select Object: The program switches to the current Map. Click an object as the processing range of the Tile. If multiple objects need to be selected, press and hold the Shift key to select objects in turn. After the selection is completed, click the right mouse button to end the selection state. Return to the Generate Map Tiles dialog box.
  - Draw Rectangle: Switch the program to the current Map, use the mouse to Draw Rectangular Range in the window, click the right mouse button after drawing, end the selection status, and return to the Generate Map Tiles dialog box.
  - Custom Expression: The program will pop up the SQL Expression dialog box, which supports the determination of Tile Bounds by setting the SQL Expression. The minimum Bounds of the expression Search Result is the Generate Tiles range.
  - Copy, Paste: The program provides Copy, Paste buttons to copy the Geographic Range. Click the Paste button at Range Settings to set the left, bottom, right, and top values of Copy Bounds to the current range.
Filter Select Object Layer: When Tile Bounds is set as the custom range mode of Select Object, check this item, and the program will automatically filter the object layer when Generate Tiles; otherwise, it will not filter. This feature only works when there are multiple layers in the map.
Completely fill the tile: If this item is checked, the contents outside Tile Bounds will not be displayed. If this item is not checked, the Tile contents outside Tile Bounds will be filled with white, which may lead to incorrect display in Merge Tiles. For example, when the user selects a city range object as the range of Generate Tiles, the effects of using and not using Completely fill the tile are shown in the following figure:

Figure 1: Completely fill the tile result Figure 2: No Completely fill the tile result
Origin of Tile: This is the basis of the Map Tiles splitting rule. When the Origin of Tile is determined, the segmentation rule of the Tile can be determined. There are three ways to set the Origin of Tile: Uppe-left corner of the map, Uppe-left corner of the window, and Paste.
- Uppe-left corner of the map: Set the Upper Left Coordinates of Whole Map to the Origin of Tile.
- Uppe-left corner of the window: Set the Upper Left Coordinates of Current Windows to the Origin of Tile.
- Paste: Set the Upper Left Coordinates of Copy Bounds to the Origin of Tile.
After setting the above parameters, you can execute the Map Tiles cutting operation. After the graph is cut, a folder named by Tile Name is generated under the set working directory, which contains a *.sci file and a tile result file. As shown in the figure below, Tile is saved in the corresponding scale folder, and the generated *.sci is TileConfig File. You can open directly as an Open Datasource. For more information on how to open a Datasource, see Open Datasource.

Figure: Map Tiles results